EOS

Congratulations to the 2021 class of Fellows! These 59 individuals have made outstanding achievements and contributions by pushing the frontiers of our science forward. They have also embodied AGU’s shared vision of a thriving, sustainable, and equitable future for all powered by discovery, innovation, and action. Equally important is that they conducted themselves with integrity, respect, diversity, and collaboration while creating deep engagement in education and outreach.

Since 1962, AGU has elected fewer than 0.1% of members to join this prestigious group of individuals.

Thanks to their dedication and sacrifice, AGU Fellows serve as global leaders and experts who have propelled our understanding of geosciences. We are confident that they will remain curious and relentlessly focused on answers as they continue to advance their research, which pushes our boundaries of knowledge to create a healthy planet and beyond.

We are grateful for their invaluable contributions. We also recognize that numerous individuals were pivotal to their success, and we thank them too.

AGU will formally recognize this year’s recipients during #AGU21 Fall Meeting, where we will celebrate and honor the exceptional achievements, visionary leadership, talents, and dedication of all 59 new AGU Fellows.

On behalf of AGU, we welcome to our community the 2021 AGU Fellows, who are listed below in alphabetical order.

—Susan Lozier, President, AGU; and LaToya Myles (unionfellows@agu.org), Chair, Honors and Recognition Committee, AGU

 

2021 AGU Fellows

Ariel D. Anbar, Arizona State University

Suzanne Prestrud Anderson, University of Colorado Boulder

Richard C. Aster, Colorado State University

Sushil Atreya, University of Michigan Ann Arbor

Andy Baker, University of New South Wales

Leonard Barrie, McGill University, Stockholm University, and the Cyprus Institute

Kristie A. Boering, University of California, Berkeley

Simon Brassell, Indiana University

Paul D. Brooks, University of Utah

V. Chandrasekar, Colorado State University

Daniele Cherniak, University at Albany

Mian Chin, NASA Goddard Space Flight Center

Paul Judson DeMott, Colorado State University

Andrea Donnellan, Jet Propulsion Laboratory, California Institute of Technology

Christopher Fairall, NOAA Boulder

Harindra Joseph Fernando, University of Notre Dame

Fabio Florindo, National Institute of Geophysics and Volcanology, Rome, Italy

Steve Frolking, University of New Hampshire

Ferran Garcia-Pichel, Arizona State University

Darryl Granger, Purdue University

Kaj Hoernle, GEOMAR Helmholtz Centre for Ocean Research Kiel

David Holland, New York University

Niels Hovius, GFZ German Research Centre for Geosciences

Fumio Inagaki, Japan Agency for Marine-Earth Science and Technology (JAMSTEC)

Vania K. Jordanova, Los Alamos National Laboratory

Kim Kastens, Lamont-Doherty Earth Observatory

Sukyoung Lee, Pennsylvania State University, University Park

Xinlin Li, University of Colorado Boulder

Peter C. Lichtner, OFM Research and the University of New Mexico

Carolina Lithgow-Bertelloni, University of California, Los Angeles

Parker MacCready, University of Washington Seattle

Donald R. MacGorman, NOAA/National Severe Storms Laboratory (retired) and Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma

Michelle Cailin Mack, Northern Arizona University

Wendy Mao, Stanford University

Jerry F. McManus, Lamont-Doherty Earth Observatory, Columbia University

Andrew J. Michael, USGS Earthquake Science Center

Glenn Milne, University of Ottawa

Onno Oncken, Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences

Victoria Orphan, California Institute of Technology

Bo Qiu, University of Hawaii at Manoa

Andy Ridgwell, University of California, Riverside

Stephen R. Rintoul, CSIRO Oceans & Atmosphere

Allen Robinson, Carnegie Mellon University

Stanley Sander, NASA Jet Propulsion Laboratory, California Institute of Technology

Keith P. Shine, University of Reading

Whendee L. Silver, University of California, Berkeley

Craig T. Simmons, Flinders University

John R. Spencer, Southwest Research Institute Boulder

S. Alan Stern, Southwest Research Institute

Dimitri A. Sverjensky, Johns Hopkins University

Roy Torbert, University of New Hampshire Main Campus and Southwest Research Institute, EOS department, Durham

Philippe Van Cappellen, University of Waterloo

Peter van Keken, Carnegie Institution for Science

Thorsten Wagener, University of Potsdam

David Wald, USGS National Earthquake Information Center

Yigang Xu, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences

Edward D. Young, University of California, Los Angeles

Xubin Zeng, The University of Arizona

Yan Zheng, Southern University of Science and Technology

All life needs nitrogen, but most organisms can use only nitrogen that has been “fixed,” or transformed into a biologically useful form by microbes. Biological nitrogen fixation was imperative to the expansion of life on early Earth, and a dearth of fixed nitrogen has even been invoked as an explanation for Earth’s “Boring Billion,” a 1-billion-year period in the Proterozoic when the expansion and evolution of life seem to have ground to a halt.

Cyanobacteria—commonly called blue-green algae—are often thought to have been the most important marine nitrogen fixers in the Proterozoic, as they are generally considered to be today. But a new discovery made in an alpine lake offers a window to Earth’s distant past, complicating that assumption.

Purple sulfur bacteria (PSB) in Proterozoic-analogue Lake Cadagno, Switzerland, can fix nitrogen at rates comparable to the low end achieved by cyanobacteria, according to researchers. This finding, published in a new study in Nature Communications, is the first time that PSB have been observed fixing nitrogen outside of a laboratory.

An Unexpected Discovery

PSB are anoxygenic phototrophs—photosynthetic organisms that don’t produce oxygen like plants and cyanobacteria do. Previously, researchers had discovered that different anoxic phototrophs called green sulfur bacteria could fix nitrogen in Lake Cadagno, but only at very low rates.

“It became very clear that the one organism that was previously shown to fix nitrogen in [the Lake Cadagno] ecosystem could not be responsible for the high rates that we measured.”As part of a short field trip in 2018, Miriam Philippi, a biogeochemist from the Max Planck Institute for Marine Microbiology in Bremen, Germany, visited Lake Cadagno and had intended to simply double-check previous measurements of nitrogen fixation in the lake.

“We were not expecting to find what we actually found,” she said. The bacteria in her samples were fixing nitrogen much faster than the previously described green sulfur bacteria should have been able to. “It became very clear that the one organism that was previously shown to fix nitrogen in this ecosystem could not be responsible for the high rates that we measured,” she recalled.

Linking Nitrogen Fixation to Purple Sulfur Bacteria

The microbial community in Lake Cadagno is variable—it is sometimes dominated by green sulfur bacteria and sometimes by PSB. When Philippi visited, PSB were so abundant that they colored her water samples pink. Additionally, the genomes of PSB previously found in Lake Cadagno contained genes for nitrogenases, enzymes responsible for nitrogen fixation. But claiming that PSB were responsible for high nitrogen fixation rates would have been unprecedented.

“There was some indication that under in situ [natural] conditions, there is potential for purple sulfur bacteria to fix nitrogen,” said Katharina Kitzinger, also a biogeochemist from the Max Planck Institute for Marine Microbiology. But PSB had never actually been observed fixing nitrogen in a natural environment.

To conclusively link PSB to nitrogen fixation, Philippi, Kitzinger, and their colleagues combined multiple approaches. Using metatranscriptomics, they showed that the majority of nitrogenase gene expression in Lake Cadagno was tied to PSB. A different set of measurements showed that PSB could fix nitrogen much faster than other noncyanobacterial aquatic microbes.

“It’s a very beautiful environmental microbiology study showing very conclusively, I think, for the first time that it is the purple sulfur bacteria that are fixing a lot of nitrogen in a natural system,” said Jennifer Glass, a geobiologist from the Georgia Institute of Technology who was not involved in the research.

Implications for the Proterozoic Ocean

Discovering that PSB fix nitrogen in Lake Cadagno is significant because of the lake’s unusual, layered structure—it has a shallow oxygenated surface layer overlying sunlit sulfide-rich bottom waters where anoxygenic phototrophs can thrive. These characteristics are thought to mimic the ocean during the Proterozoic eon. And if PSB fix nitrogen in Lake Cadagno, they might have been important players in the Proterozoic nitrogen cycle, too. This challenges the assumption that cyanobacteria were the only dominant nitrogen fixers in the Proterozoic, which could have rippling implications for Earth’s past biogeochemical cycles.

“Just because a compound has a lower availability in terms of concentration doesn’t mean that microbes can’t make use of it.”One possible limit on Proterozoic life could have been nitrogen because the most important nitrogenase enzymes contain molybdenum—an element that was likely scarce in the Proterozoic ocean. Lake Cadagno’s waters are likewise poor in molybdenum, but the PSB there could still fix nitrogen effectively. And although Kitzinger cautioned that it’s impossible to know exactly what the nitrogen cycle looked like in the past, the new result could indicate that nitrogen fixation might not have been as severely impeded by the Proterozoic molybdenum limitation as sometimes hypothesized.

“Microbes just find a way to function irrespective of the concentration,” Kitzinger said. “Just because a compound has a lower availability in terms of concentration doesn’t mean that microbes can’t make use of it.”

—Elise Cutts (@elisecutts), Science Writer

Internal Earth cooling occurs by a combination of passive heat conduction and active fluid flux between the crust and the surface. While thermal conduction is the main cooling mechanism in most parts of the ocean basins, hydrothermal circulation dominates near mid-ocean ridges. However, the reach and intensity of off-axis circulation as the newly formed crust cools and migrates away from the spreading center is still poorly known.

By combining realistic maps of rock physical properties retrieved by seismic waveform tomography with hydrothermal modelling techniques, Kardell et al. [2021] present compelling evidence that hydrothermal circulation is a significant cooling factor up to crustal ages of 60 to 65 million year, in excellent agreement with previous estimates and observations. These results should be incorporated in Earth cooling models and may serve as a reference to plan future seafloor drilling expeditions.

Citation: Kardell, D. A., Zhao, Z., Ramos, E. J., Estep, J., Christeson, G. L., Reece, R. S., & Hesse, M. A. [2021]. Hydrothermal models constrained by fine-scale seismic velocities confirm hydrothermal cooling of 7–63 Ma South Atlantic crust. Journal of Geophysical Research: Solid Earth, 126, e2020JB021612. https://doi.org/10.1029/2020JB021612

—Valentí Sallarès, Associate Editor, JGR: Solid Earth

Although we rarely stop to consider it, Earth’s magnetic field is an important part of our daily lives. The magnetic field protects our planet from charged particles emitted by the Sun; high doses of these particles can cause malfunctions in the electrical grid and in satellites.

But thanks to complex processes unfolding deep within Earth, the magnetic field is ever changing. To predict what it might do in the future, scientists are looking deep into the past.

This is no easy task—intentionally kept human records of the magnetic field exist for only the past few hundred years. To see further back in time, scientists rely on “accidental” records, as well as on volcanic and sedimentary rocks, said Lisa Tauxe, a geophysicist at the Scripps Institution of Oceanography. Tauxe is a coauthor of a new study that used ancient artifacts to analyze changes in Earth’s magnetic field thousands of years ago—as far back as 7600 BCE. The study was published in the Proceedings of the National Academy of Sciences of the United States of America.

These accidental records, Tauxe explained, can be created when certain materials are heated to very high temperatures. When they cool, magnetic minerals within the material are frozen in place, providing a snapshot of the direction and strength of Earth’s magnetic field at the time.

Clues from the Past

Ancient pottery is a robust and widely used way to study the history of Earth’s magnetic field. But in the context of geologic history, pottery poses a problem for researchers who want to delve deeper into the past. That’s where the present study comes in.

“In this study, what we did was to try to push the record back beyond pottery,” said Tauxe.

These researchers wanted to see whether they could obtain information about the magnetic field from flint, one of the most common materials used to make stone tools. It is thought that ancient humans deliberately heated the flint to make it easier to work with, said study coauthor Anita Di Chiara, a paleomagnetist at Scripps and at Italy’s National Institute of Geophysics and Volcanology.

Heated flint dates back much further than pottery, likely to around 50,000 years ago, so it could potentially substantially increase our understanding of the magnetic field’s past.Heated flint dates back much further than pottery, likely to around 50,000 years ago, so it could potentially increase our understanding of the magnetic field’s past by a substantial amount. Di Chiara said that obtaining data from flint is difficult because it is generally not very magnetic. However, in this study, researchers were able to obtain data from tiny amounts of impurities in the flints.

Using artifacts from Jordan, including both flint and pottery, researchers found that the magnetic field around 7600 BCE was only two thirds the strength of today’s field but just 600 years later had greater strength than today’s field. Then, around 5200 BCE, it weakened again.

Today, said Tauxe, the strength of Earth’s magnetic field is dropping very quickly. Although this change isn’t necessarily catastrophic, Tauxe said it could cause problems for some types of technology. “Our electrical grid and satellites will become more vulnerable to solar storms.… We need to build our infrastructure with that in mind—that we’re losing the protection of the magnetic field.”

Although Tauxe said the overall strength of the field won’t be very low for another 500 or so years, she noted that one region of the world, an area over parts of South America and the South Atlantic Ocean, is already experiencing an unusually weak magnetic field. This weak spot, called the South Atlantic Anomaly, can leave satellites vulnerable to charged particles, which can cause glitches and malfunctions.

Early Humans

Although studying the magnetism of ancient objects is important for understanding the magnetic field’s history, it could also help us understand human history. Erella Hovers, a professor of prehistoric archaeology at the Hebrew University of Jerusalem, said that studying the magnetism of ancient artifacts can be very useful in an archaeological context. Such study can help archaeologists determine the relative ages of ancient human-made objects. This method is especially useful for objects that are beyond the scope of carbon dating, which is effective only for things that are less than 50,000 years old.

For example, she said, archaeomagnetism allows scientists at older sites to “see if the features [they’re] studying were created at one particular point in time, which would suggest something about the rapidity of the site being formed, or whether it’s just a big hodgepodge of things that were mixed in place and were originally formed in different periods.”

Both Tauxe and Di Chiara emphasized the collaborative nature of this work and noted the importance of partnerships between geophysicists and archaeologists in learning more about Earth’s magnetic history.

—Hannah Thomasy (@HannahThomasy), Science Writer

Rising seas threaten communities and ecosystems around the world. Efforts to stave off sea level rise—or mitigate the effects—will benefit from accurate predictions of how quickly it could occur.

Now new research by Ding et al. investigates and confirms the existence of a 64-year fluctuation in Earth’s global mean sea level; incorporating this repeating pattern into calculations of sea level rise predictions could improve their accuracy, according to the authors.

The new findings build on earlier analyses of historical tide gauge data that suggested the existence of a fluctuation in global mean sea level that repeats about every 6 decades. Alongside global warming, such a cycle could have contributed to accelerations in sea level rise detected via satellite radar altimetry over the past 30 years.

To confirm the existence of this multidecadal fluctuation, the researchers applied a novel method to analyze data from 44 separate tide gauge sea level records dating from 1933 through 2019. The technique they used is called optimal sequence estimation, which is a data stacking approach designed to detect patterns shared between different geoscience data sets.

The analysis confirmed that alongside fluctuations on other timescales, global mean sea level fluctuates regularly about every 64 years—by an average of about 1 millimeter and up to 18 millimeters in some ocean regions. The researchers validated their findings using additional data from 94 other tide gauges.

The research team also confirmed that the 64-year cycle can have a significant impact on calculations of regional sea level rise, indicating the importance of accounting for it to ensure accurate estimates in the future.

Meanwhile, what causes the fluctuation is unclear. However, the researchers note that it corresponds to certain fluctuations observed in Earth’s magnetic field, as well as to periodic oscillations in the length of a full day on Earth. These other patterns are associated with processes inside Earth’s core, and it is possible that the same core motions underlie the 64-year sea level fluctuation. (Journal of Geophysical Research: Solid Earth, https://doi.org/10.1029/2021JB022147, 2021)

—Sarah Stanley, Science Writer

In July, the Australian geosciences community was shocked to learn that the globally recognized School of Earth and Planetary Science at Macquarie University in Sydney had been culled as part of the university’s efforts to deal with pandemic-related revenue losses. This was the latest blow after a prolonged, nearly 2-year downsizing process during which 18 of the 21 academics who worked at the school have now been let go and, with them, Macquarie’s ability to provide a well-rounded geoscience education. In the wake of this purge, the three remaining staff are left to bear what remains of the teaching load.

Unfortunately, this was not an isolated event. A string of mergers, cutbacks, and closures have hit geoscience departments across Australia in response to the recent financial pressures and low undergraduate enrollment numbers. The Australian National University Research School of Earth Sciences in Canberra made drastic cuts in December 2020, including a massive reduction in its operating budget and laying off 20 permanent staff members, plus additional contract employees. This layoff resulted in reduced levels of technical support across the entire school, the closure of its renowned mechanical workshop, and a major reduction in the research capability of the world’s first SHRIMP (Sensitive High-Resolution Ion Microprobe) mass spectrometer laboratory, responsible for dating many of the oldest known Earth and extraterrestrial materials ever discovered.

In 2020, 17,300 university jobs were lost across Australia. A federal decision to cut funding for Earth and environmental science courses by 29% has only compounded the situation.Meanwhile, at the University of Newcastle, the geology major was dropped completely. In total, seven of the 21 Australian geoscience departments have been hit with substantive reductions in staffing and curriculum offerings in the past few years, and many others have suffered smaller reductions.

Although faults in Australian geoscience education predate COVID-19, the significant financial pressure inflicted upon Australian universities as a result has catalyzed its rapid fragmentation. More casualties are likely to come as the Australian university sector is forecast to lose up to AU$19 billion (US$13.7 billion) between 2020 and 2023 because of the collapse of international student revenue. The federal government’s refusal to financially back the university sector has forced institutions across the country to consolidate their educational offerings to those that generate the greatest profit margin. In 2020, 17,300 university jobs and AU$1.8 billion (4.9% of 2019 revenue) were lost across Australia, with a further 5.5% drop estimated for 2021. Research-related staff have been particularly hard hit, with women, early-career researchers, and recent graduates disproportionately affected. A 2020 federal decision to cut funding for Earth and environmental science courses by 29% has only compounded the situation, setting the sights of financially strapped universities looking to cut overhead squarely on the backs of geoscience departments.

The loss of these geoscience resources could not come at a worse time. Australia faces unprecedented environmental and energy challenges while simultaneously trying to revitalize an economy stunted by the COVID-19 pandemic. To tackle these challenges and ensure a sustainable and prosperous future, Australia needs the very geoscience expert community currently being diminished.

Geoscience, as the interface between humanity and Earth, is essential to tackling climate change and will aid in the economic recovery from COVID-19. The United Nations (UN) and the World Bank have championed geoscience as critical to reaching the UN’s Sustainable Development Goals, disaster risk reduction, and achieving the goals of the Paris Agreement (e.g., clean energy technologies will greatly increase the demand for critical minerals).

What, then, has led Australia to jeopardize its ability to respond to these challenges by making deep staffing cuts and closing entire geoscience programs? What measures can be taken to save Australian geoscience? And what implications does this have for the international geoscience community?

Broadening and Refocusing the Geoscience Narrative

Even before the COVID-19 pandemic, student enrollment in geoscience majors was in decline across Australia, despite increasing demand from diverse geoscience industry sectors. Although undergraduate enrollment appears anecdotally to be bouncing back in Western Australia following a post-2016 revival of the mining industry largely based there, student numbers in southeastern geoscience departments have not rebounded sufficiently to ensure their viability. The problem is that many people in the more urbanized southeastern states and territories view mining as the only career option for someone who pursues geology studies, an industry they understand to be detrimental to the environment.

This enrollment crisis extends beyond the shores of Australia.

Undergraduate geoscience enrollment trends in Australia, the United States, and United Kingdom since 2003. National enrollment data are normalized to the maximum enrollment for each country during the recorded time span. Although national undergraduate enrollment data for geoscience subjects are not yet available post-2017 in Australia or after 2019 in the United Kingdom, it is expected that the downward trends in student numbers will be exacerbated by the COVID-19 pandemic. Data sources are the Australian Geoscience Council, the American Geosciences Institute, and the U.K. Higher Education Statistics Agency (HESA). HESA undergraduate geoscience enrollment data for the United Kingdom are unavailable prior to the 2014–2015 academic year.

The United Kingdom has also seen a progressive decline in undergraduate geoscience enrollment since 2016. It has been attributed to a parallel reduction in geology course offerings in primary and secondary schools. Geoscience enrollment has similarly collapsed in the United States over the past 5 years, a trend that predates the 2019–2021 shrinkage of employment prospects in the U.S. petroleum, mining, and geological engineering industries. These numbers are all made more complicated by the pandemic, including challenges in charting enrollment during virtual learning.

Thus, a global recasting of the geoscience narrative as a mechanism for meeting the challenges of science and society is needed to better reflect the true merit and breadth of its disciplinary applications.

It must be made clear that contrary to many inaccurate public perceptions, the expertise and capabilities of the mining and petroleum industries will play a fundamental role in the global fight against climate change.If we’re going to convince young people that a geoscience education can lead to rewarding careers, we need to remold geoscience curricula so they align with contemporary student values. First, it must be made clear that contrary to many inaccurate public perceptions, the expertise and capabilities of the mining and petroleum industries will play a fundamental role in the global fight against climate change. Simply put, without meeting the fivefold increase in demand for critical minerals and sequestering 190 billion metric tons of carbon dioxide into sedimentary basins, we will fail to reach the Paris Agreement carbon neutrality targets. However, economic geology courses should be accompanied by interdisciplinary lessons on environmental and mining ethics, which could form a more substantive component of classes on Earth resources. While maintaining core geoscience education and pursuing fundamental research, broader societal applications should also be incorporated into our curricula, including subjects on sustainability, water resource management, geoengineering, and the mitigation of natural and anthropogenic hazards. These are just a few ideas for rebranding the discipline to accommodate the cultural differences between those who want to pursue employment in the geological resource sector and those who do not.

This adaptation of geoscience curricula for a new era must involve substantive change, not simply be lip service to creating a more progressive career tract. In at least one high-profile case in the United States, small changes to geoscience syllabi were insufficient to attract students, so the university is now attempting a full overhaul of the Earth science curriculum so it will focus on preparing students to meet the pressing challenges of today.

What is clear, however, is that in many places, the current model is not attracting enough students for geoscience departments to remain viable in a financially weakened university sector. A community-wide dialogue is thus needed to develop a revived and unified geoscience education narrative that captures the imagination of young minds.

National Strategies for Geoscience Education and Research

The nation’s ability to sustainably secure food, energy, and water is also reliant on the capacity of its geoscientists to discover, manage, and responsibly use its natural resources.Perhaps more than any other developed nation, Australia’s wealth and prosperity depend on its geoscience expertise. This year alone, the country’s mineral and energy resource sector is forecast to generate AU$296 billion (US$214 billion) in export earnings (~10% of GDP) and will no doubt be key to powering Australia’s recovery from the tumultuous economics of the COVID-19 era. The nation’s ability to sustainably secure food, energy, and water is also reliant on the capacity of its geoscientists to discover, manage, and responsibly use its natural resources.

It is therefore in the government’s own best interest to preserve its geoscience capacity. Australia needs a national strategy for geoscience education and research to temper the fiscal decisions of universities and ensure a future geoscience workforce. Previous programs designed to build national capacity, such as the Australian Mathematical Sciences Institute and the Minerals Tertiary Education Council (MTEC), were greatly successful in drawing increased enrollment when they were established over a decade ago. Indeed, the MTEC program contained many elements that could be implemented again today, with industry-funded teaching positions in critical geoscience disciplines created at several universities across the country, development of aligned national geoscience curricula, and funding travel for students to visit and study at other hubs across the country.

With new investment aligned to a national geoscience education strategy, teaching hubs across several universities could be identified and developed in areas of strength and strategic importance, such as renewable energy and critical mineral exploration, applied geophysics, water resource management, carbon sequestration, and geohazard mitigation. David Cohen, president of the Australian Geoscience Council, recently advocated for such a national geoscience professional development system. Cohen argued for a partnership between industry, government, universities, and professional societies, so that the system can deepen the skills of existing geoscientists while simultaneously providing a pathway for scientists from other fields to transition into the discipline.

When developing strategies to bolster its geoscience capacity, Australia might also look to the United Kingdom. In response to diminishing geoscience enrollment there, the Geological Society of London and University Geoscience UK have developed strategic aims to reinvigorate undergraduate-level geoscience education. In them, they lay out a multifaceted action plan for revamping geoscience education, funding, marketing, and diversity across a wide range of stakeholders to avoid the looming skills shortage. Addressing the geoscience maladies of Australia will require a similarly comprehensive strategy to be formulated and implemented by an alliance of geoscience departments, academic and professional societies, research infrastructure providers, industry advocates, and policymakers.

Saving Geoscience

Meeting the geoscience labor force needs of national and global communities must, therefore, become a strategic imperative for our universities.Ensuring a sustainable and prosperous future, both in Australia and abroad, requires saving and empowering the geoscience community. Although geoscience departments produce relatively few graduates each year compared with other STEM (science, technology, engineering, and mathematics) disciplines with which they compete for university funding, they are, nevertheless, required to produce the skilled geoscientists demanded across a variety of industries critical to societal well-being. Meeting the geoscience labor force needs of national and global communities must, therefore, become a strategic imperative for our universities.

To do this, national strategies involving geoscience, university, industry, and government stakeholders are needed that rebrand geoscience in line with contemporary student values, align secondary school curricula to teach geoscience in the context of societal betterment, and develop and fund nationally coordinated university research and education programs in areas of community priority.

Acknowledgments

We acknowledge the contributions of Mike Sandiford, Olivier Allard, Alan Collins, Annette George, and Jonathan Palmer for their informative input and suggestions.

Author Information

Samuel Boone (samuel.boone@unimelb.edu.au) and Mark Quigley, University of Melbourne, Melbourne, Vic., Australia; Peter Betts, Monash University, Clayton, Vic., Australia; Meghan Miller, Australian National University, Canberra; and Tim Rawling, AuScope, National Collaborative Research Infrastructure Strategy Program for Geosciences, Melbourne, Vic., Australia

27 September 2021: This article was updated to remove a reference to the University of New South Wales.

In a warming world, it is crucial to study the evolution of temperature extremes, such as heatwaves and wildfires. These extremes carry severe implications for water availability, soil conditions, and food production with consequences on economic sectors and human stability.

Ajjur and Al-Ghamdi [2021] demonstrate that temperature extremes would increase “unprecedently” over all global land areas, with a notable change observed in the coldest days and nights. When comparing the end of the twenty-first century (2071-2100) with the historical period (1981–2010), they project a temperature increase up to 7.4oC in the warmest day, 6.6oC in the warmest night, 10.9oC in the coldest day, and 12oC in the coldest night parameters, under the business-as-usual scenario. The global hotspots affected mainly by this increase are North America, Iceland, Central Asia, the Russian Arctic, Siberia, the Mediterranean, and the Middle East and North Africa.

The trend in temperature extremes is “unequivocally” linked to anthropogenic influences, such as greenhouse gas emissions and land use activities. The authors argue that “dismissing the evolution in temperature extremes leads to reactive-way management relying on emergency responses, making temperature extremes exact their toll”.

Ajjur, S. B., & Al-Ghamdi, S. G. [2021]. Global hotspots for future absolute temperature extremes from CMIP6 models. Earth and Space Science, 8, e2021EA001817. https://doi.org/10.1029/2021EA001817

—Jonathan H. Jiang, Editor, Earth and Space Science

The motion of material in Earth’s mantle, powered by heat from the deep interior, moves tectonic plates on our planet’s surface. This motion generates earthquakes, fuels volcanic activity, and shapes surface landscapes. Furthermore, chemical exchanges between the surface and Earth’s mantle possibly stabilize the oceans and atmosphere on geologic timescales. A book recently published by AGU, Mantle Convection and Surface Expressions, gathers perspectives from observational geophysics, numerical modelling, geochemistry, and mineral physics to construct a holistic picture of the deep Earth. We asked the book’s editors some questions about what readers can expect from this monograph.

In simple terms for a non-expert, can you start by explaining what the mantle is, how material moves around the mantle, and the effects of this on Earth’s surface?

The mantle is the largest region in our planet, connecting the hot liquid outer core to Earth’s surface. Convection in the Earth’s mantle is linked to plate tectonic processes and controls the fluxes of heat and material between deep mantle reservoirs and the atmosphere over time. A better understanding of these deep-mantle material cycles and their impact on the long-term evolution of our planet requires integrated approaches that involve all disciplines in the Earth sciences.

A better understanding of deep-mantle material cycles and their impact on the long-term evolution of our planet requires integrated approaches that involve all disciplines in the Earth sciences.For example, geochemical observations on the surface suggest different chemical reservoirs within the lower mantle. This would imply potentially widespread variations in physical properties driven by the chemical differences between materials.

The connection between chemical variations and physical property changes needs to be quantified by experimental and theoretical mineral physics. In turn, the constrained variations in physical properties provide the basis for self-consistent state-of-the-art geodynamic models of mantle convection.

Finally, the predictions of geodynamic models can be quantitatively tested by geophysical observations, which constrain the geometry of sinking slabs and rising plumes, as well as geochemical data.

Any such models rooted by observational and theoretical constraints can be applied to study the evolution of the mantle over billions of years, thereby linking the accretion of our planet to the present-day. Indeed, such an interdisciplinary effort can even provide insight into the conditions for planetary habitability and sustainability of higher life.

What motivated you to write a book on mantle processes and surface expressions?

We believe that real progress is increasingly made at the intersection between different sub-disciplines and, ultimately, only the synergy between disciplines can truly overcome the limitations of each individual approach.Our book aimed to unify researchers with expertise in different Earth science disciplines, including observational geophysics, numerical modelling, geochemistry, and mineral physics, to outline current concepts on dynamic processes occurring in the mantle and associated material cycles. We believe that real progress is increasingly made at the intersection between different sub-disciplines and, ultimately, only the synergy between disciplines can truly overcome the limitations of each individual approach. Our book is motivated by the vision of a new holistic picture of deep Earth sciences.

How is your book structured?

The overarching idea of the book is to bridge between disciplines. The sub-sections of the book are not sorted by discipline, but rather by research topic. The first part describes key mantle domains and basic properties of the Earth’s mantle. The second part presents reviews and new research related to the dynamic aspects of deep Earth material cycles, integrating all relevant geoscientific disciplines. The third part aims to place the preceding chapters in a broader context, trying to summarize ideas and stimulate new concepts on how the Earth’s deep mantle is connected to our planet’s surface and atmosphere, and how processes might work on other planets.

What value did you find in bringing together perspectives from different scientific disciplines in your book?

Several high-profile papers have been published relating to mantle convection and surface connections during the past decade, including materials cycles through the deep Earth interior and its impact on the evolution of the atmosphere.

The value that our book adds is to summarize existing multidisciplinary work and foster future research across the boundaries.Progress has been significant, but often work still falls mostly within one discipline. Some initial progress in multidisciplinary work has been made, but is still often complicated by gaps in knowledge, jargon, and networks.

The value that our book adds is to summarize existing multidisciplinary work and foster future research across the boundaries.

How do you hope that your book will inspire further transdisciplinary research?

Despite the common call for transdisciplinary research, only little work has been done that truly and quantitatively integrates different approaches. Sometimes, just the lack of a common language, with different jargon across discipline boundaries, prevents any directed and sustainable progress.

We are convinced that our book can help to bridge the gaps between different Earth Science communities, resolve some semantic issues, and foster promising future collaborations. In order to achieve this, we took particular care that chapters are written in a style that makes them accessible for researchers from all sub-disciplines (i.e., jargon and pre-conceptions are explained).

The topic “Mantle Convection and Surface Expressions” covers an area of central importance for all target research disciplines and is central to our understanding of the evolution of our planet. Thus, we feel that the topic is not only a ‘hot-topic’ of cross-disciplinary importance but is also ideally suited to unify researchers and trigger fruitful future work.

Mantle Convection and Surface Expressions, 2021, ISBN: 978-1-119-52861-6, list price $249.95 (print), $200 (e-book). AGU members receive 35 percent off all books at Wiley.com. Log in to your AGU member profile to access the discount code.

—Hauke Marquardt (hauke.marquardt@earth.ox.ac.uk, 0000-0003-1784-6515), University of Oxford, UK; Maxim Ballmer ( 0000-0001-8886-5030), University College London, UK; Sanne Cottaar ( 0000-0003-0493-6570), University of Cambridge, UK; and Jasper Konter ( 0000-0002-4853-5456), University of Hawaii at Mānoa, USA

Editor’s Note: It is the policy of AGU Publications to invite the authors or editors of newly published books to write a summary for Eos Editors’ Vox.

Après Snowpack • The Challenges of Forecasting Small, But Mighty, Polar Lows   • The Changing Climate’s Snowball Effect   • How the Ski Industry Stopped Worrying and Learned to Love Climate Activism   • How Infrastructure Standards Miss the Mark on Snowmelt   • The Who, What, When, Where, and Why of the Polar Vortex   • Testing on the Tundra: NASA Snow Program Heads North   • SnowSchool Spans the States   • Winter’s Melting Point  

When you think about snow, what comes to mind? Sledding and hot chocolate? Shoveling and wet boots? “As a native U.S. East Coaster, I never had much of an appreciation for the importance of snow—it was exciting as a kid and can be somewhat of a nuisance as an adult,” said Ellyn Enderlin of Boise State University and Eos’s Science Adviser representing AGU’s Cryosphere section.

“It’s really difficult to grasp the importance of snow when you’re focused on driving down slippery roads, but it’s important that society collectively realize that changes in snowpack have impacts beyond winter sports, days off from school, and difficulties commuting to work. The changes also profoundly influence the natural system, from microscopic to global scales.” Enderlin and Merritt Turetsky, our Biogeosciences Science Adviser, suggested the theme of our October issue and consulted on its development.

We start with Marta Moreno Ibáñez, who writes about the challenges of forecasting polar lows—the phenomenon that can result in sudden, dangerous conditions including strong winds and heavy snowfall. Until the dawn of the satellite era, not much at all was known about polar lows. Today scientists have a better handle on why they form but still have to work out the nuances of the many processes involved in warning people when to take shelter from one.

Then we take a look at The Changing Climate’s Snowball Effect on our planet. It used to be that city planners would know how much water to anticipate in their reservoirs by measuring the snowpack at the top of the mountain. These days, one measurement isn’t nearly enough to predict the runoff, leaving planners high and dry when all of the water anticipated doesn’t appear. Our reporting looks at the complex variables scientists and policymakers must start accounting for and how they work with communities who aren’t always ready for change.

Winter ski enthusiasts are coming to the realization that climate change is coming for the sport they love, and the reckoning may be an example for us all.“Snowmelt is an incredibly important source of water in the western U.S., in terms of both human use and ecosystem services, but snowpack has decreased dramatically in the past several decades while the regional population has grown,” said Enderlin. “It seems as though people are finally becoming more aware of the importance of snow, yet little action has been done to reduce the greenhouse gas emissions that are driving changes in snowpack and the timing of its melt.”

Finally, read more about one industry that is gearing up for action. Winter ski enthusiasts are coming to the realization that climate change is coming for the sport they love, and the reckoning may be an example for us all. Just ask professional snowboarder Jeremy Jones, who founded Protect Our Winters, a nonprofit organization that recently led a campaign to oust the head of the International Ski Federation after he went on record as a climate change denier. In July, four of the biggest North American ski resorts signed on to a charter to enforce unity in climate advocacy and make real changes in their business operations—but they know they alone can’t save winter. This advanced lesson in how to bring equivocators on to the boat is one we could all learn from.

—Heather Goss (@heathermg), Editor in Chief

Après Snowpack • The Challenges of Forecasting Small, But Mighty, Polar Lows   • The Changing Climate’s Snowball Effect   • How the Ski Industry Stopped Worrying and Learned to Love Climate Activism   • How Infrastructure Standards Miss the Mark on Snowmelt   • The Who, What, When, Where, and Why of the Polar Vortex   • Testing on the Tundra: NASA Snow Program Heads North   • SnowSchool Spans the States   • Winter’s Melting Point  

It begins at the height of winter in the mountains, when the landscape is particularly inhospitable. The surveyors arrive on skis, snowshoes, and snowmobiles. Some fly in by helicopter. Others travel the backcountry for days. When they arrive at their destination, there’s critical information to collect: the depth of the snowpack and how much water it holds. For regions confronting the effects of climate change, more and more hinges on the results.

“It all boils down to how much water makes it down into the reservoir,” said Sean de Guzman, chief of snow surveys and water supply forecasting at the California Department of Water Resources. De Guzman has it easier than some. Between February and May, around the first of each month, he drives to the Phillips Station snow course—a designated site for measuring the snowpack—located at around 6,800 feet (2,100 meters) of elevation in the Sierra Nevada. Once there, he manually inserts a tube into the snowpack, an instrument and method developed in the early 20th century by James Church, a professor at the University of Nevada, Reno who wanted to help put an end to local water wars by finding a way to estimate how much Lake Tahoe would rise in springtime. With the tube, de Guzman is able to measure the snowpack’s snow water equivalent, or the amount of water the snowpack contains at that location.

Today there are approximately 1,600 snow courses in the United States, with around 260 in California, primarily in the Sierra Nevada and the southern Cascades. Some date back more than a hundred years. Data from these locations, said de Guzman, represent the longest-running climate record in the Sierra Nevada. In the West, manual snow surveys are augmented by data from an automated snow telemetry (SNOTEL) network maintained by the Department of Agriculture’s Natural Resources Conservation Service that provides hourly snowpack measurements.

What these collective data tell snow surveyors, water resources managers, policymakers, and millions of people enduring water shortages, drought, flooding, and wildfires is that the snowball effect of climate change often begins, appropriately enough, with snow. And snow—how much falls, where and when, how much accumulates, and how quickly it melts—is changing.

“As a whole, over the last 70 years, we’ve seen a decline in snowpack,” de Guzman said. “With the warming temperatures and a warming climate, you can expect the snow-line—basically where that snow transitions into rain, and vice versa—to increase,” or climb in elevation.

Even when the snow survey data are relatively promising, other climate factors can inhibit a favorable outcome. At 59% of average on 1 April, California’s 2021 winter snowpack had more snow than was measured in any of the state’s 2012–2016 drought years. At the height of that drought in 2014, the snowpack on 1 April was at only 5% of average. And yet, de Guzman said, the 2021 snowpack yielded about the same amount of runoff as during those very dry years. “If you have more snow, you expect more [runoff], but that didn’t happen this year,” he said. The reason in part was that another low-rainfall year resulted in dry soil, which soaked up more of the runoff. “The snowpack was melting,” de Guzman said, “but the rivers weren’t rising.”

A Shrinking Season

There are different contexts and consequences across the United States, but all regions are struggling with rapid change. While the West grapples with water shortages amid severe drought, other parts of the country have become more vulnerable to extreme thunderstorms and flooding as more precipitation falls as rain rather than snow and as snowmelt occurs earlier in the spring. Increasingly, snow will also accumulate later in the season. An analysis by Climate Central showed that between 1970 and 2019, snowfall measured in 116 U.S. locations had decreased by 80% before December, and at 96 locations it had decreased by 66% after 1 March. But though historical data can reveal broad regional trends and patterns, they are becoming a less reliable forecasting tool as the warming climate throws snowfall patterns into disarray.

“The snow season is shrinking,” said Hans-Peter Marshall, an associate professor in the Cryosphere Geophysics and Remote Sensing group at Boise State University. But how much snow falls within that shortened seasonal window, he said, is difficult to predict. “The main thing we know is there’s going to be larger fluctuations, and the year-to-year variability is likely to increase.”

That variability includes the possibility of heavier snowstorms even as temperature averages trend upward. There’s no consensus on why warming has what appears to be a counterintuitive impact. According to Marshall, one reason the western United States might experience bigger storms is that a heated atmosphere can hold more water. In a warmer climate, water from the ocean could potentially make its way to the mountains, and more of that water might fall as heavy snow or torrential rain.

Meanwhile, warming Arctic temperatures may contribute to the kind of frigid blasts that reached as far south as Texas in 2021 (with catastrophic results) by disrupting the polar vortex, weakening the Northern Hemisphere’s polar jet stream and causing Arctic temperatures to dip south and warmer air to move north.

In the West, as the snow season shortens and the snowpack shrinks, so too does the water supply. In August, the federal government for the first time declared a water shortage on the Colorado River, a move that will reduce the amount of water allocated to Arizona and Nevada in 2022. (Mexico will also see a reduction in its share of the Colorado.) A continued water shortage will reduce water allocated to California.

“If you’re living in the West, you’re going to feel it,” said Amato Evan, an associate professor of climate sciences at the University of California, San Diego’s Scripps Institution of Oceanography. “In regions where the snowcap is vulnerable, like California, we’ve had year after year of 46 drought already,” demonstrating that the consequences are real.

The mountain snowpack, Evans said, acts as the state’s water bank for the year, melting slowly over the course of the summer and refilling depleted reservoirs. But snow that melts too early overwhelms reservoirs and can’t be captured and stored for use later in the year. And runoff that evaporates in warm, dry conditions or, as de Guzman described, gets absorbed into the earth before it reaches reservoirs, results in low water supply early on in the season.

A Recipe for Disaster

Both scenarios may have far-reaching consequences. In California, 2021’s lower than forecast runoff contributed to drought emergency proclamations being declared in May, for 50 of the state’s 58 counties, with state agencies directed to instigate a series of measures to conserve the water supply.

According to Marshall, the entities that decide how much water to release from dams must constantly estimate how much remains in the seasonal snowpack—decisions made more challenging by unpredictable snowfall. Though snow surveys and telemetry data provide accurate measurements for the area immediately surrounding snow courses and sensors, the data aren’t necessarily indicative of what’s happening between the sites. Currently, Marshall said, water managers might take a survey site’s 30-year average, compare it with streamflow over 30 years, and find the statistical correlation between the two. But that approach depends on a stationary climate, and these days, Marshall said, the current year is rarely representative of the past 30.

“As predictions get harder and harder in a changing climate,” he said, “we’re at this point where we need to make a paradigm shift, [and go] from just looking at individual sites and correlating them over the last 30 years to actually being able to estimate how much snow is everywhere on the landscape.”

Marshall and his group at Boise State are helping to fill in the data gaps by supporting NASA’s SnowEx campaign, which uses coordinated airborne and field experiments to determine the best combination of sensors for measuring snow globally from space. Current monitoring from space can tell scientists where snow cover is located but not how much of it there is.

“We’re operating old infrastructure in a changing climate, and that is a recipe for disaster.”“That’s one of the largest components of the water cycle that we just don’t have a very good handle on,” Marshall said.

When Marshall first began his work in Idaho in 2008, water managers showed less interest in new approaches than they do today. As the climate changes, weather events are altering the snowpack in unique ways, making reliable forecasting technology crucial for implementing decisions that affect water allocation for agriculture, water supply for communities, and flood forecasting.

According to de Guzman, incorporating forecasts into infrastructure operations, rather than relying on historical data, would enable water managers to better determine when to release water from reservoirs.

“A lot of the regulations and operations and maintenance manuals on how we operate reservoirs are built off old historical data,” de Guzman said. “So we’re operating old infrastructure in a changing climate, and that is a recipe for disaster.”

All Over the Map

In the Midwest and Northeast, less snowfall and more rain affect everything from agriculture, as farmers struggle with soil erosion, to the recreation industry, as the snow sport season shortens. In both cities and rural areas, increased rainfall and more frequent severe snowstorms will strain critical infrastructure systems and put vulnerable populations at risk.

In the Great Lakes region, warmer temperatures reduce ice cover on lake surfaces, leaving water open for lake-effect snowstorms. Increases in these storms in the short term could overwhelm snow and ice removal systems and affect roadways, buildings, and power lines. In the long term, as temperatures continue to climb, the air moving over the lakes will be warmer, and rain will fall instead of snow.

Abigail McHugh-Grifa is a founding member and executive director of Climate Solutions Accelerator of New York’s Genesee-Finger Lakes Region, which includes the city of Rochester where the nonprofit is based. McHugh-Grifa sees signs that the climate is changing. “Certainly we are already seeing the impacts of the weather just getting weirder and more unpredictable at all times of the year,” she said, adding that in the past few years, heavy snowfalls have quickly melted rather than accumulating. “It will dump a lot of snow on us and then melt and then dump a lot of snow on us and melt again. It’s just all over the map.”

“Even though we are seeing extreme weather conditions and other impacts of climate change, most local municipalities and community members aren’t making the connection yet.”Patterns can be difficult to tease out in an area like Rochester, where winter is the fastest warming season. The city has experienced a slight downward trend in snowfall over the past 50 years, with a more dramatic decline expected in the next 20–30 years, according to Climate Central meteorologist Sean Sublette in an interview for Rochester’s WROC TV. But in the short term, Rochester, like other Great Lakes communities, will likely see more lake-effect snowstorms, followed by warming springtime temperatures that can hasten snowmelt and lead to, among other changes, disruptions to the growing season.

For McHugh-Grifa, whose organization seeks to engage the community and public officials in mapping out solutions for adapting to climate change, getting leaders to recognize the urgency of the task can be the biggest challenge. “I wouldn’t say that any municipality around here is being bold enough or ambitious enough in their approach,” she said. “Even though we are seeing extreme weather conditions and other impacts of climate change, most local municipalities and community members aren’t making the connection yet.”

New York is a home rule state, meaning in short that municipalities have the autonomy to pass local laws. McHugh-Grifa believes that for public policies to shift toward climate adaptation planning, multiple municipalities must get on board. “If one municipality wants to go above and beyond, it’s challenging for them because there’s a real fear that, for example, if they…demand higher standards for building efficiency, then the developer is just going to go to the next town over.”

Without increased regional cooperation and collaboration on land use, transportation, and building codes, McHugh-Grifa said, policy planning for climate change adaptation will continue to stall. In part to respond to this challenge, Climate Solutions Accelerator uses a collective impact approach, working to convene partners, ensure that the voices of those most affected are represented, and develop a shared regional plan. “No one organization or one individual or one solution can possibly meaningfully address this problem, so we need this kind of massive coordinated response,” she said.

In many urban areas where snow, and winters in general, are predicted to transform in the decades ahead, climate action plans have been developed to set goals for reducing greenhouse gas emissions. Chicago, Boston, and Philadelphia are among the U.S. cities that have joined C40 cities; a global network of so-called megacities whose mayors have pledged to deliver on climate change goals. Ultimately, with sharply divided political positions among top elected officials, local leaders may have the largest influence on whether their cities can adapt quickly enough to meet the changing climate.

A Climate to Reckon With

In Alaska, one of the fastest warming regions on the planet, the effects of changing winter patterns—including snowfall, snowmelt, and permafrost thaw—will have wide-ranging ramifications for the state’s human and wildlife inhabitants. Many animals and native or migrating fish depend on snow, ice, and streamflow for habitat. Communities rely on snow for transportation and recreation and on snowmelt for hydropower. Uncertainties for such key industries as timber and fisheries contribute to economic vulnerability.

In northern coastal areas, Alaska Native communities that hunt for subsistence or migrate to work depend on the sea ice and permafrost—a layer of frozen ground—for survival. As the ice melts and the permafrost thaws and becomes less stable, villages may lose homes and other structures to flooding or erosion. Diminished mobility cuts off access to hunting and fishing grounds and isolates residents from emergency services. In some cases, the thaw has proven fatal.

“In the last couple of years, we’ve had at least a dozen people go through unstable ice,” said Amy Lauren Lovecraft, director of the Center for Arctic Policy Studies and a professor of political science at the University of Alaska Fairbanks. “It’s unimaginably tragic,” she said. “It’s the people who don’t produce or produce very little carbon emissions who are most impacted.”

And yet, Lovecraft said, current and past governors have been careful to avoid politically charged policies that directly address climate change, leaving it to villages and boroughs to take on the role of strengthening their communities. “In the absence of federal or state direction, it’s happening at the local scale,” Lovecraft said, adding that, in fact, these communities know best about how changes in snow affect them. “It’s not an entirely negative thing that it has to happen from the bottom up.”

Still, there is a role for the state to play, Lovecraft said, including setting parameters, spreading information, and backing local-scale projects that address mobility, housing, hunting, and other concerns. “It’s a matter of how smooth that transition could be,” she said.

As scientists continue climate research and refine technologies for accurate forecasts and measurements, communities will need to find support for applying new methods and data and implementing policies that address specific changes in their regions. But for some areas already deeply affected by changing winters, paradoxical weather events and the vagaries of snowfall patterns, winter storms, and snowmelt may hinder efforts to communicate the urgency of taking action.

Ultimately, the question for Alaska, Lovecraft said, isn’t whether the science on climate change is correct but, rather, whether it’s a message that anyone wants to hear.

“Does Alaska really want to face the pain of doing a transition that’s conscious, or do we ignore it? Eventually, we’re going to have to reckon with it.”

Author Information

Korena Di Roma Howley (korenahowley@gmail.com), Science Writer

Après Snowpack • The Challenges of Forecasting Small, But Mighty, Polar Lows • The Changing Climate’s Snowball Effect • How the Ski Industry Stopped Worrying and Learned to Love Climate Activism • How Infrastructure Standards Miss the Mark on Snowmelt • The Who, What, When, Where, and Why of the Polar Vortex • Testing on the Tundra: NASA Snow Program Heads North • SnowSchool Spans the States • Winter’s Melting Point

An interview with the president of the International Ski Federation, Gian Franco Kasper, made its way around the Internet faster than locals flocking to the first chair on a powder day. In the 2019 interview, Kasper told a Swiss newspaper that he preferred working with dictators to environmentalists and that there is no proof of “so-called” climate change. The International Ski Federation represents more than a hundred national ski organizations in the world and organizes the Olympic ski events.

Many did not take kindly to Kasper’s remarks. Days after an English translation of snippets from the interview was published in the sports publication Deadspin, the outdoor community sent a letter with nearly 9,000 signatures to the federation demanding that Kasper step down.

The letters said that climate change threatens the existence of the ski industry and that Kasper’s comments went against the experience of resorts that have already closed because of climate change. “Kasper’s remarks should disqualify him for a leadership position in any business capacity, let alone that of a ski federation,” read the letter from the nonprofit Protect Our Winters (POW).

Kasper apologized, and 7 months later, the International Ski Federation signed on to the United Nations Sports for Climate Action Framework. This year, Kasper retired after 23 years as president and was replaced by a candidate, Johan Eliasch, endorsed by John Kerry, the U.S. special presidential envoy for climate.

Skier and mountaineer Caroline Gleich swapped her ski gear for a blazer and slacks before testifying before Congress in February 2020. Gleich is a salaried athlete influencer for the nonprofit Protect Our Winters. Credit: Caroline Gleich

The shift in perspective symbolized by Kasper’s final years in office reflects a concern by the industry that winter may become a shell of its former self. Already, the snow-water equivalent in the western United States has dropped 41% since the early 1980s, and the ski season has decreased by 34 days. Half of all Northeast ski resorts may go out of business by 2050, and climate modeling predicts that 90% of ski resorts in the West won’t be financially viable by 2085 if greenhouse gas emissions aren’t curtailed. Not that they’ll have much to drink anyway: snow melt provides up to 75% of the water supply in western states.

Until recently, “there was an ethos within the outdoor industry and even the outdoor community to try and remain apolitical, and [these groups] saw climate change as a political issue,” said Mario Molina, executive director of POW, which organized the letter campaign to oust Kasper.

Social media abuse would rain down on those daring to mention climate change, Molina said. Trolls descended on athletes speaking about climate, telling them to stick to their sport. Resorts risked angering customers when unleashing new sustainability initiatives.

Outdoor enthusiasts remained ambivalent. A 2020 POW report focused on the United States concluded that members of the community—people striving for physical sensations, for inner well-being, or to achieve new personal records—“are not prime candidates for abstract communal action.”

But the same report showed that 90% of outdoor enthusiasts think climate change is caused by humans. The report also found that people who participate in outdoor sports are politically diverse: Democrats make up 40% of outdoor enthusiasts, whereas 31% are Republican and 29% identify as independent. The results were based on surveys of 2,100 people across a variety of sports, interviews with professional athletes, and online focus groups.

Downhill Emissions

Ski resorts are cutting emissions in creative ways.

Aspen Skiing Company in Colorado partnered with a local mine operator to trap methane from one of its coal mines that would otherwise leak into the atmosphere. The methane powers the ski area, producing energy equivalent to what’s needed to power roughly 2,400 homes. Berkshire East Mountain Resort in Massachusetts powers itself on 100% renewable energy using solar and wind on site. Jackson Hole Mountain Resort in Wyoming operates 100% on wind energy purchased from a wind farm in neighboring Idaho.

Skiing and snowboarding produce greenhouse gas emissions by powering ski lifts, snowmaking, and lodges. Tourists fly and drive across the world to ski, staying in chateaus and drinking at heated outdoor bars. But cutting their emissions won’t stop global climate change.

“Even a victory like a large corporation cutting its carbon footprint by 30 percent—the stuff of Shazam-level super-heroism and incredibly difficult to pull off—wouldn’t even dent the climate problem,” wrote Aspen Skiing Company senior vice president of sustainability Auden Schendler in the Stanford Social Innovation Review in 2021. “Systemic change is the only path to climate stability.”

For their sport to survive climate change, skiers will need to not only cut their emissions (see downhill emissions) but also somehow convince the rest of the world to cut its as well.

Because the industry’s longevity relies on the actions of others, it has been slowly emerging as a vocal advocate for broad-based systemic climate reform. Activists have been spinning two webs of influence to enact change: (1) creation of an influencer-led, identity-driven voter bloc and (2) a jobs-first pitch to lawmakers on Capitol Hill.

The NRA of Skiing

The National Rifle Association (NRA) is not a group most would associate with skiers and snowboarders. But Schendler said the cohorts have more in common than you might expect.

“This is a unmobilized cohort that could swing elections.”“It’s a very similar group if you think about why they’re motivated,” Schendler said. “They’re gun people in the same way that I have a friend who says, ‘I don’t climb, I’m a climber.’ ‘I don’t ski, I’m a skier.’”

“Think about gun owners, and then think about who’s just as amped up, passionate, influential, wealthy, crazed? Well, it’s the outdoor [community]. These are all fanatics,” he said. Just look at how they spend their time: Skiers hit the slopes wearing garbage bags in the rain. Climbers live in their vans chasing the next project. Runners don headlamps to clock kilometers before dawn. “This is an unmobilized cohort that could swing elections.”

If emissions remain unchecked, the snow season will be cut at least in half by midcentury at many ski resorts in the contiguous United States. Credit: NOAA

The NRA has outsized power in Washington despite its middle-of-the-road spending on lobbying. As Gallup reports, although most people in the United States approve of gun control, Congress hasn’t imposed tighter regulations.

Even the NRA’s election spending is a fraction of what companies or individuals invest in attempting to sway polls.

“The NRA is not successful because of its money. To be sure, it is hard to be a force in American politics without money. The NRA has money that it uses to help its favored candidates get elected. But the real source of its power, I believe, comes from voters,” said Adam Winkler, a professor of constitutional law at the UCLA, School of Law and author of Gunfight: The Battle over the Right to Bear Arms in America, told the Guardian in 2018. The organization remains one of the most powerful lobbying groups in Washington.

No longer are skiers and snowboarders just people who like chasing powder for fun; they are citizens of the “Outdoor State,” a body politic that demands their allegiance and fidelity.As the chairperson of POW’s board, Schendler has talked about the NRA as an inspiration for years. POW’s mission is to mobilize millions of outdoorsy people to climate action. Although POW originally focused on snow sports like skiing and snowboarding, the organization’s target demographic now includes climbers, trail runners, and bikers as well.

POW mobilizes its base by reframing the political identity of an outdoors person, complete with voter guides and influencers. No longer are skiers and snowboarders just people who like chasing powder for fun; they are citizens of the “Outdoor State,” a body politic that demands their allegiance and fidelity.

The Influencer Economy

Professional snowboarder Jeremy Jones founded POW in 2007, and ever since, the organization has recruited a collection of famous athletes to spread its message. “What makes POW different and unique—and I think where our potential really lies—is in this cadre of influencers,” Molina said.

The more than 100 athletes in POW’s alliance program have received training in science, advocacy, and clean energy. In exchange, they agree to appear at a certain number of public speaking events, to write op-eds and social media posts, and to generally exist as POW ambassadors. The arrangement is somewhat like the billion-dollar industry of influencers who represent corporate brands on Instagram and other social media sites. But most of POW’s athletes volunteer their time apart from four paid “team lead” athletes who manage volunteers.

Tommy Caldwell, a world-famous rock climber with 820,000 Instagram followers, hosted an event with the League of Conservation Voters to get out the vote.Premier athletes like skier Hilaree Nelson, who boasts the first ski descent of the fourth-highest peak in the world (Lhotse, in China and Nepal), touts POW to her 59,200 followers on Instagram. Tommy Caldwell, a world-famous rock climber (821,000 Instagram followers), endorsed Joe Biden for president because of his climate-friendly policies and hosted an event with the League of Conservation Voters to get out the vote in 2020. Endurance runner Clare Gallagher (44,500 Instagram followers) penned an op-ed in UltraRunning magazine in April 2021 on coping with climate anxiety.

In the U.S. Senate race in Montana in 2018, POW athletes rallied around Democratic candidate Jon Tester, a two-term senator with a proenvironment voting history.

Mountaineer Conrad Anker of Bozeman and fly-fisher Hilary Hutcheson of the greater Missoula area led the charge. The two gave press interviews, wrote op-eds, and posted on social media in support of Tester, all of which POW shared with its followers through social media, email, and the web, said Auden. Tester won by nearly 18,000 votes.

Although it’s unclear how much POW played a role in Tester’s victory, athletes drawing in incremental votes is exactly the organization’s mission, Schendler said.

Other organizations also target environmentally conscious voters. The nonprofit Environmental Voter Project (EVP) reaches out to people who consider the environment one of their main political issues but visit the polls only in presidential elections. This cohort could pack a punch: An EVP report from this year found that environmental voters could swing 2022 midterms in six purple states if they showed up. These voters are predominantly young, female, and disproportionately Hispanic, Asian American, and Pacific Islander.

Like POW, EVP wants to remake the model of a “good environmentalist” from someone who recycles or is a  vegetarian into someone who votes in all elections, big or small.

Protect Our Winters founder Jeremy Jones, rock climber Tommy Caldwell, and ski mountaineer Caroline Gleich testify in front of the Senate Democrats’ Special Committee on the Climate Crisis in Washington, D.C., in 2019. Credit: Jesse Dawson

Consumer preferences force businesses to adapt, too. A 2016 study of 83 Western ski resorts published in Strategic Management Journal found that “environmental institutional pressures”—defined as regulatory, normative, and cultural pressures—have led to increased adoption of climate change mitigation practices by resorts. These pressures were more successful at forcing resorts to adapt than were the adverse effects of climate change itself.

“I think we were able to actually nudge the entire industry into the realization that civic engagement is not a political activity.”In June, four of the biggest North American ski resort companies (Vail Resorts, Alterra Mountain Company, POWDR, and Boyne Resorts) signed a charter to enforce, among other things, unity in climate advocacy.

On the retail side, 82 brands have now joined POW’s brand alliance by giving $5,000 or more to the nonprofit. Burton and Patagonia have both contributed more than $150,000.

The recent events suggest that athletes, resorts, and brands agree that talking about climate change is now fair game. POW’s Molina credits his organization for this shift in opinion. “I think we were able to actually nudge the entire industry into the realization that civic engagement is not a political activity,” he said.

The next question is, What will the industry and its fans do with their newly found voice?

From the Statehouse to Capitol Hill

Fifty million Americans participate in outdoor sports, and the pandemic inspired many to visit parks for the first time. Although it’s easy to think of a solo paddle or a hike through a reclusive forest as far from an economic activity, outdoor adventures leave a trail of money in their wake: The gear. The clothing. The transportation. The marathon registration. The cabin. The after-trip milkshake.

But climate change threatens that money train: U.S. downhill skiing, just one subset of the outdoor economy, lost $1.07 billion over a decade because of lower snow years between 1999 and 2010, according to a 2012 POW and Natural Resources Defense Council report. This downturn led to a loss of up to 27,000 jobs, a drop in unemployment of as much as 13%.

Since the release of that 2012 report, there’s been a race to calculate just how much outdoor recreation is worth. POW releases estimates, the Outdoor Industry Association (OIA) has reported its own, and more estimates are in the works.

American consumers spend more on outdoor recreation than they do on pharmaceuticals and fossil fuels combined.In 2016, Congress passed an order for a thorough assessment of how much money the outdoor sector contributes to the U.S. economy. The Bureau of Economic Analysis set up a special fund for this purpose and in 2020 published a tally: $459.8 billion of current-dollar gross domestic product came from outdoor recreation in 2019. (The amount is half of the current-dollar gross domestic product from all arts and cultural activity in the country in 2019.)

According to a 2017 OIA report, American consumers spend about $887 billion on outdoor recreation annually. That is more than they spend directly on pharmaceuticals and fossil fuels combined.

These billions of dollars in market power form the backbone of lobbying by the outdoor industry. “It literally changed the conversation in Washington,” said advocacy lead Chris Steinkamp at Snowsports Industries America (SIA), who led POW previously.

Before hard economic numbers appeared, the ski industry appealed to lawmakers by expressing a love of winter and a fear of its expiration date. Now advocates tout the sector’s economic contribution to the U.S. economy. In Colorado alone, the ski industry generates $4.8 billion annually, according to a study by Colorado Ski Country USA and Vail Resorts.

Trade Organizations Band Together Amid Criticism

In 2019, SIA partnered with two other outdoor trade organizations to amplify their voices in Washington. Their goal is to use a jobs-first agenda to spur legislative climate wins.

The Outdoor Business Climate Partnership (OBCP) combines the power of SIA, which is a collection of winter recreation retailers, suppliers, resorts, and sales reps; the National Ski Areas Association (NSAA), which includes more than 300 alpine ski resorts and more than 400 suppliers; and OIA, an industry heavy hitter that represents 1,200 businesses in outdoor sports from big names like REI to small family shops.

The new partnership targets lawmakers in such states as Utah, Colorado, and New Mexico, where recreation is a major part of the state’s economy. OBCP’s priorities include putting a price on carbon, passing a clean energy standard, and supporting clean transportation.

Lawmakers on both sides of the aisle have aligned with OBCP. The partnership hosted Democratic Rep. Joe Neguse from Colorado and Republican Rep. John Curtis of Utah at a virtual event earlier this year, for instance.

Bipartisanship is at the heart of OBCP’s mission. “We can’t shame our elected officials into agreeing with us,” said Steinkamp. “We have to be allies and not adversaries.”

Steinkamp said that OBCP doesn’t spend time talking to or supporting lawmakers who are climate skeptics, however. Instead, they home in on Republicans like Curtis, who recently launched a conservative climate caucus.

“We were very strategic with the name because we wanted to be very clear that we were embracing the science with climate, but that we were conservatives,” Curtis said of the caucus in an interview with C-SPAN. “Today there are 65 members. It grows every day.”

Snowpack in the Sierra Nevada dropped sharply in 2015 (left) compared with 2010 (right). Credit: Jesse Allen/NASA

The industry’s cross-party approach has attracted criticism, however.

The political contributions of ski resorts and their executives came under scrutiny following a 2016 article by Porter Fox in Powder magazine. Fox, a former Powder editor and author of Deep: The Story of Skiing and the Future of Snow, wrote that industry tycoons such as executives from Vail Resorts and Jackson Hole gave money to candidates or political action committees with a record of opposing climate legislation, according to records from the Center for Responsive Politics.

“We should be thanking these members of Congress, not attacking them.”In a rebuttal, NSAA director of public policy Geraldine Link wrote, “The ski industry, like every other industry, is not ‘single-issue’ in its approach to advocacy.” Republican candidates who were singled out in the article helped protect water rights and support year-round activities, she wrote. “We should be thanking these members of Congress, not attacking them.”

Three years later in an opinion piece in the New York Times, Fox responded. Supporting candidates who bolster year-round activities and water rights but not climate isn’t enough, he wrote. “The time for soft-pedaling passed decades ago. At this very late stage in the game, the snow sports world needs decisive action.”

To achieve the Paris Agreement target of limiting average global warming to 1.5°C, relative to pre-industrial temperatures, the world will need to phase out all carbon emissions by 2040. Humanity has made some progress: Before the Paris Agreement was reached, we were headed toward 3.6°C warming. Now we’ve got that down to 2.9°C.

But we have a long way to go: 2°C would still bring catastrophic climate impacts. And the world will need to make emissions cuts like those from the COVID-19 shutdowns every year for the next decade to keep warming below 1.5°C.

Charting a Line for Years to Come

Famed alpinist and POW athlete Graham Zimmerman spent much of his twenties chasing peaks around the world. Even though he studied glaciohydrology in college, he pushed climate change to the back of his mind. And when he did think of it, he felt guilty for all the plane flights, car rides, and gear he tore through as an international athlete.

But in the 20-minute documentary An Imperfect Advocate from Outside TV, Zimmerman argued that climate activism is for everyone—even those with large carbon footprints. We see Zimmerman calling his representatives and visiting statehouses, high schools, and universities to talk up climate change policy.

“Our goal with solving the climate crisis is not to stop traveling, or stop heating our homes,” Zimmerman said. Instead, it’s to continue to do the things that “inspire us and drive us” but with carbon-neutral or carbon-efficient technologies. “And that all comes from government.”

An Imperfect Advocate represents a tension in climate activism that goes back decades. To halt carbon emissions and slow global warming, should individuals put their energy toward cutting their carbon footprint? Or should people focus on calling for top-down regulation from lawmakers? And what if the emitter isn’t a person, but an industry? Must an industry walk the walk before sticking its neck out for systemic change?

“The outdoor industry and winter sports industry are not the largest carbon emitters, but we rely on those larger [emitting] sectors like transportation and electricity,” said Amy Horton, senior director of sustainable business innovation at OIA. The dependence on these carbon-heavy activities is a catch-22: Carbon pollution is still needed to bring customers, but it’s also slowly eroding away the sport’s future.

A review of 119 research studies of climate change risk to ski tourism across 27 countries, shows clearly that the industry is in for a shake-up. Resorts can’t depend on natural snow anymore. They’ll need to pump more water and burn more power to make artificial snow, ski areas will close, ski seasons will shrink and shift, ski markets will bend and morph as skiers travel for snow or give up the sport altogether, and real estate values will shoot up or down accordingly.

The industry finds itself at a crossroads that environmental activists have long pondered: How can climate policy pass in the United States when the politics remain so divisive?

Steinkamp of OBCP doesn’t think the discussions over the past 10 years demanding immediate action have spurred productive policy, however. Although bipartisanship “takes time,” he said, “I think this is where we see the long-lasting change happening.”

POW has put its bet with a strong voter base of outdoors people—a group that overwhelmingly believes in climate change but is politically diverse—who it says could sway elections. OBCP is betting on forging relationships with emerging Republicans who believe in climate change to adopt climate legislation.

“I think this ship is slowly moving in the right direction,” Molina said of recent partnerships in the outdoor industry. “The next year or two will actually show us how many of the new coalitions and groups that have emerged are going to really put their weight behind the statements.”

Author Information

Jenessa Duncombe (@jrdscience), Staff Writer

The width of bedrock channels is a key factor controlling erosion and transport processes in mountain rivers. Channel width controls flow dynamics, the force exerted on the riverbed, and therefore erosion and sediment transport rates. A narrowing river will concentrate the flow over a small area, potentially enhancing sediment transport and erosion rates, and may generate obstructions. Conversely, a widening river may undermine the hillslopes and make them more unstable, leading to increased hillslope erosion and sediment supply.

Bedrock riverbed and banks are commonly eroded by the repeated impacts of sediment grains during floods. While some models exist that relate the rate of vertical incision to a river’s sediment flux and grain size, the influence of these parameters on the erosion of bedrock walls (and therefore on channel width) is not as well understood.

In an earlier paper, Li et al. [2020] proposed a model that predicts the erosion of bedrock walls through repeated impact by sediment grains by tracking the trajectory of each grain, but such models require huge computational power and time. In a new paper, Li et al. [2021] now provide an analytical solution, that is, a series of equations that replicate the results of the earlier model without needing to track every single grain.

This new model is much faster and can easily be integrated in models of landscape evolution, thus providing a new tool to explore more completely the interactions between sediment flux, grain size, channel width and the propagation of perturbations along rivers and up valley sides.

The model shows the circumstances in which one may expect rivers to narrow or widen as a function of how much sediment is coming through the river and what its grain size is, and is tested against a real river, Boulder Creek, in California.

Citation: Li, T., Venditti, J. G., & Sklar, L. S. [2021]. An analytical model for lateral erosion from saltating bedload particle impacts. Journal of Geophysical Research: Earth Surface, 126, e2020JF006061. https://doi.org/10.1029/2020JF006061

—Mikaël Attal, Editor, JGR: Earth Surface

Reviewers are critical to ensure quality and rigor in scientific publications. In most cases, their contributions are hidden because of our masked peer review system but, while many choose to remain anonymous to authors, it’s important that we know who they are and where they are. To mark Peer Review Week 2021, we wanted to share how AGU has been tracking and analyzing reviewer demographics. We shared previous work on reviewer demographics [Hanson and Lerback, 2017; Lerback et al., 2020] and, over the past few years, have continued to work on expanding the reviewer pool to engage a wider range of perspectives and ultimately publish more inclusive science benefiting larger sector of society. Expanding our reviewer pool also helps to supply an increasing demand for peer reviews as scientific output and submissions increase.

Sources of Demographic Information

AGU has several methods for identifying reviewer demographics. First, we use our member database to match authors and reviewers in our journal submission system with their member profiles containing gender, age, and race/ethnicity information. When  gender is not given in the member profile, we use the gender-name database Gender API, which uses first name and country to guess and we keep guesses with +90% confidence score. Some of the race/ethnicity categories are based on U.S. census categories (e.g., Asian American), so our current race/ethnicity data only applies to U.S.-based reviewers. However, we are in the process of updating our system so that the categories accurately describe the global population. Country of residence is determined from a person’s profile in the submission system. For those that don’t have it, we use their email suffix (when it identifies a country).

Gender of Reviewers

The number of invitations to review a paper sent to women (both total counts and percentages) has been increasing since 2016, although the rate at which they agree to review is slightly lower than male invitees, so the proportion of women agreeing to review papers (“final (agreed) reviewers” in the chart below) has nominally increased each year:

It’s tricky to develop a specific target for invitations to women, as reviewing receives less professional credit than publishing articles, leading research groups, chairing department committees, and other activities. Some members of the community are worried that over-burdening women scientists with reviewing will take their attention away from activities that more overtly advance their careers.

AGU is currently working on expanding co-reviewing opportunities, which will allow senior scientists to partner with those earlier in their careers to work together on reviews.However, by increasing reviewing opportunities for early career scientists, which, in the Earth and space sciences includes a higher proportion of women than older cohorts, younger scientists will benefit more from reviewing papers than those advanced in their careers. AGU is currently working on expanding co-reviewing opportunities, which will allow senior scientists to partner with those earlier in their careers to work together on reviews. This will help train early career scientists in peer review and expand future opportunities to review.

Geographic Region of Reviewers

An interesting comparison is between the location of the invited reviewer and the geographic region where our corresponding authors are located, as shown in the chart below. Though we’ve seen an increase in the proportion of review invitations sent to regions where we see the fastest growth in authors submitting papers, namely China, the increase in invitations isn’t as large as the increase in accepted papers from China. Additionally, the proportions of invitations sent to U.S.-and Europe-based reviewers have been declining but are still higher than their representation in our pool of authors whose papers are published.

Age of Reviewers

It’s important to disaggregate gender data by age group to see where specific improvements can be made. These next charts show age groups of reviewers, authors, and AGU members.

People invited to review papers are predominately mid- to late-career men (40s-60s). The largest cohort of women invited to review are in their 30s.

We typically compare invited reviewers to authors of accepted papers and members, shown below. Both authors and members are skewed slightly younger than invited reviewers, which indicates editors are more comfortable inviting those in the mid- and later-career stages. This could be due to the expertise of those in these stages (including being known published authors) or because these reviewers are a part of the editor’s professional network.

Increasing reviewing opportunities to younger scientists could help decrease the burden on mid-career scientists who likely have more teaching, administration, and/or family-related duties while having the benefit of training younger scientists earlier in their career on how to do a good peer review.

Reviewer Workload

Another interesting way to assess the diversity of our reviewer pool is to calculate the number of invitations per person within various demographic groups. For example, are we inviting the same men more often than we’re inviting the same women? We can calculate this by dividing the number of total invitations by the number of distinct email addresses belonging to that demographic group, with the chart below showing the resulting invitations per person.

The results show that we invite fewer women than men and much fewer unknown gender (majority China-based) than either gender. We also see that as the years progress, we are inviting the same men and women less often.

This decrease in invites per person is also seen in invited reviewer country-region. The chart below shows editors are inviting people in the U.S. more often than those in all other country-regions. However, we also find that we are inviting people by region less often indicating that in 2020, we expanded our reviewer pool.

Reviewing during the COVID-19 pandemic

Across the scientific community, there was considerable concern about how the pandemic would affect people’s capacity to submit papers and their ability to review. In May of 2020, we looked at the initial impact of the pandemic on our submissions; we now have enough data from the past year to understand how this has impacted our community.

Submissions increased overall and across all demographic groups (based only on the corresponding author) with proportions varying only slightly with no statistically significant difference between in-pandemic and pre-pandemic periods. Editors and associate editors invited slightly more reviewers in their 20s and 30s and slightly fewer in their 40s and 50s compared to previous years. Reviewer agree rates dropped a few points among women and increased a few points among men in 2020, as shown in the chart below.

Overall, paper submissions and reviewer activities increased (more submissions, more peer reviews) likely because stay-at-home orders were conducive to these types of desk-based activities (see survey conducted by the American Geosciences Institute on work habits in 2020). Though many survey-based studies showed that women (and men) with children reported less productivity and decreased job satisfaction, we found that these effects of the pandemic weren’t reflected in AGU submission and reviewing rates.

Increasing and Diversifying our Reviewer Pool

The pandemic illuminated the need to expand the reviewer pool, and also made AGU and other scholarly publishers—and quite acutely society at large—consider ways to make processes and systems more inclusive and equitable. Peer review plays a seemingly small part, but the effects on advancing the scientific record could be massive. So, what are some ways we’re trying to increase reviewer representation in key demographic groups?

We ask authors to consider suggesting reviewers who are in historically underrepresented groups in the Earth and space sciences, such as women, early career scientists, and racial minorities. We encourage editors to invite more author-suggested reviewers, not just for those papers but for other submissions. Though there is a worry that some authors suggest their “friends,” these names help to expand the reviewer pool when used for other submissions on a similar topic. We are deliberately increasing editor and associate editor appointments in target demographic groups. This chart shows that they do invite more reviewers from their region:

We’ve enforced term limits and renewals to help our editorial boards to make room for new perspectives. We’ve created author and reviewer resources in other languages (e.g., webinars in Chinese and Spanish and author resources in Chinese and Japanese. We encourage editors to engage younger women for associate editor and reviewer roles when the pool of advanced career women is overworked.

The pandemic impelled us to be even more thoughtful about who contributes to decisions about what gets published. Reviewers are the backbone to that endeavor.Our community takes very seriously our responsibility to publish accurate science that takes into account multiple perspectives and opinions, especially as human-caused climate change threatens to upend our way of life.

The pandemic impelled us to be even more thoughtful about who contributes to decisions about what gets published, which ultimately contributes to the solutions to address our society’s most pressing challenges. Reviewers are the backbone to that endeavor.

—Paige Wooden (pwooden@agu.org, 0000-0001-5104-8440), Senior Program Manager, Publications Statistics, American Geophysical Union

For decades, traditional silicon-based photovoltaic cells have been the industry standard for converting sunlight into electricity—but as a photon-absorbing material, silicon is not actually all that efficient. On average, solar panels made with crystalline silicon convert between 18% and 22% of the Sun’s energy into usable electricity, with an upward theoretical limit of 33%. Despite this limitation, crystalline silicon photovoltaic cells account for 95% of the solar cell market.

By layering traditional silicon cells with a mineral called perovskite, however, materials scientists are engineering more efficient tandem solar cells that significantly boost efficiency, without derailing well-established silicon cell manufacturing pathways.

“Tandem solar cells have significantly higher energy-conversion efficiency than today’s state-of-the-art solar cells. Thus, tandem cells can contribute to lowering the cost of solar energy, in particular in rooftop solar systems, where high efficiency is of central importance,” Dirk Weiss, a materials scientist with First Solar, recently wrote in Joule. “A new generation of low-cost tandem cells is needed to enable widespread implementation. Hybrid-perovskite top cells combined with silicon bottom cells are currently the most popular low-cost tandem candidate under development.”

In a new perspective, published in Applied Physics Letters, a team led by Laura Miranda Pérez, head of materials research at Oxford PV in the United Kingdom, and Chris Case, the chief technology officer at Oxford PV, presents a case for commercializing tandem solar cells by combining existing silicon cell technology with synthetic variants of the perovskite.

The mineral perovskite, also known as calcium titanate, was discovered in the Ural Mountains in 1839, but the perovskite used in solar cells is synthesized in a lab from readily available components. These perovskite solar materials can be applied in very thin layers, making them an ideal material to add to existing silicon cell manufacturing processes.

“Perovskites can enhance and advance silicon technologies without interrupting manufacturing.”“Perovskites are the perfect partner for a tandem system with silicon,” said Miranda Pérez.

By adding perovskite, which more efficiently captures the blue region of the solar spectrum, to silicon, which targets the red region, Oxford PV has set a record solar cell efficiency of more than 29.5%. With further development, efficiencies could reach as high as 39%, said Miranda Pérez. Other research teams have demonstrated that photovoltaic cells made with only perovskite and no silicon are also viable, but these solar cells cannot exceed the practical efficacy of any single solar cell, which is around 26%. The multijunction or tandem approach of Oxford PV is the best way to break the 26% practical efficiency barrier, said Miranda Pérez.

“Of all the alternative solar cell technologies, silicon/perovskite tandem cells are proving to be the most promising because they offer a degree of tunability that you don’t have with a lot of the competing technologies,” said Joseph Berry, a senior research scientist at the National Renewable Energy Laboratory in Golden, Colo., who was not involved in the new study. “This new perspective does a great job of showing how perovskites can enhance and advance silicon technologies without interrupting manufacturing.”

Scaling Sustainably

Oxford PV, a company cofounded in 2010 by University of Oxford physicist Henry Snaith, has focused on developing perovskite-on-silicon tandem cells since 2014. Initially, ensuring the long-term stability of perovskite was the principal challenge, but current perovskite-on-silicon tandem cells have passed key accelerated stress tests for solar cells, known as the IEC 61215, established by the International Electrotechnical Commission. The tandem cells are expected to meet or exceed the industry expectation of 25 years or more of durability in the field.

The team’s next step is to ramp up production at Oxford PV’s factory in Brandenburg, Germany, which houses the world’s first perovskite-on-silicon production line, with a capacity of 100 megawatts. “The line build-out has been completed, and we will be taking tandem cells into the market next year,” Miranda Pérez said.

Initially, the company’s solar cells will be made available for residential rooftops, where space is at a premium. With additional production capacity, Oxford PV has set its eyes on commercial rooftops and utility-scale applications. “As a company we are very concerned about the climate crisis, and the best way we can play our part is to deploy this technology as quickly as we can,” said Miranda Pérez.

As countries commit to reducing emissions to meet U.N. climate goals by 2050, solar power is projected to become more pervasive. “I think tandem technologies will be requisite to hit future solar and climate goals,” Berry said.

“We want to help people understand the huge potential of perovskite-on-silicon tandem technology to boost the efficiency of solar installations and to help the world reach the goal of providing sustainable energy for all,” said Miranda Pérez.

—Mary Caperton Morton (@theblondecoyote), Science Writer

From our perch, surrounded by the undulating sea, we watch a single wave approach. The wind does not roar so much as it pushes. I am recalled to childhood memories of standing on a train platform with my mom as an express line confidently coasts through the station, ruffling our coats as it speeds by and creating just such a push. Today the wind at sea hovers only at about a Beaufort 6—a strong breeze—but it makes me feel small, nonetheless.

The approaching wave is not especially big—I’ve swum with bigger waves, coming face-to-face with rolling masses of water that traveled hundreds, if not thousands, of kilometers to meet me. But it’s not small either, and in this moment, I am overcome by the same sensation of being immersed in the sea and watching an oncoming wave. This time, though, as I track the propagating undulation, I am perfectly dry, dressed not in a swimsuit, but in grimy jeans, worn boots, and a spectacularly tacky, deli mustard–yellow Hawaiian shirt festooned with grape bunches.

If seeing a wave that traveled across the ocean to meet you is a miracle of nature, then watching that wave roll by without so much as adjusting your balance is a miracle of engineering.Now the wave is here, an azure mass of water rolling toward us. As it surges and contorts around the incongruous steel structure supporting us above the water, the wave becomes unstable and breaks, throwing its celebratory whitecap directly under our feet and wetting our soles. The visible sign of breaking comes with its compulsory auditory signature, a resounding crash, eliciting uncontrollable, inarticulate, and giddy whoops of delight from my colleagues and me.

Our lapse in professionalism draws a rebuke directly from the captain, standing on the navigation bridge 6 meters above our heads, and we snap back to reality: It’s fall 2017, and we are in the middle of the Southern California Bight, participating in a major scientific field study aboard a historic, one-of-a-kind oceanographic platform.

We scurry up a series of steel ladders and return to our duties. Later, as I lie in my bunk—a few meters below the water line—I forgive myself. If seeing a wave that traveled across the ocean to meet you is a miracle of nature, then watching that wave roll by without so much as adjusting your balance is a miracle of engineering. And for that, we can afford some giddiness.

Out at Sea but High and Dry

The Floating Instrument Platform (FLIP) is a unique asset in the U.S. ocean research vessel fleet. Technically, FLIP is not a ship or a vessel; it is a platform. Well, to be precise, FLIP is a very, very large spar buoy, a type of cylindrical float that sits upright at the ocean surface and is specifically designed to respond minimally to surface wave motions.

FLIP lies in its horizontal position as it is towed to a research location off the coast of California. Credit: John F. Williams/U.S. Navy, CC BY 2.0

This 109-meter buoy comprises what looks like the front of a ship that’s had its aft section replaced by a 90-meter-long, 4-meter-wide steel pipe resembling the working end of a baseball bat. In its resting state, FLIP floats lengthwise at the ocean surface. For expeditions, it is towed out to sea and, living up to its name, “flips” 90° to “stand” vertically at the surface.

Flipping is achieved by quite literally scuttling (a nautical term for purposefully sinking) the ballasted tubular end of the platform. This controlled, partial sinking—often with the full complement of personnel and equipment aboard—is executed precisely and expertly by the crew, who must be eternally commended for their perfect record in 390 attempts. Although the whole process takes 20–30 minutes, most of the motion occurs in about 90 seconds, taking the platform from an angle of less than 20° to fully vertical. During this time, crew and passengers execute a slow-motion, Fred Astaire–like dancing-on-the-ceiling routine, sans tuxedoes.

After the flip is complete, the “boat” section perches above the water surface. This section contains most of the usable space and sleeping quarters, which meet the comfort standards that satisfied a 1960s era Navy sailor—the word spartan comes to mind. All the interior scientific laboratory space, a galley, and other workspaces are connected by a network of exterior steel ladders and grates. Together with three foldable booms, they give the platform the appearance of a giant mechanical cephalopod or perhaps the treehouse of Peter Pan’s Lost Boys reimagined for the movie Waterworld.

Conceived, designed, and built between 1960 and 1962, FLIP was originally intended to allow collection of precise acoustic measurements at sea. Frederick Fisher and Fred Spiess almost casually presented their ingeniously engineered platform in a journal publication that ran barely 11 pages. By 1969, FLIP had been modified with booms—the arms of the aforementioned cephalopod—to facilitate additional science, and it was being used for major field campaigns.

FLIP was so well engineered to remain motionless amid the waves that during a deployment in the northern Pacific in late 1969, the entire crew had to abandon the platform after 3 days of confinement inside without any power. Tom Golfinos, FLIP’s long-serving captain, and esteemed oceanographer Robert Pinkel, both of Scripps Institution of Oceanography, recounted to me that large Pacific swells overtopped the platform, reaching 15 meters above the still water line and knocking out power. As it had been designed to do, FLIP simply stood impassive as these massive waves broke around it, vindicating its designers but terrifying its occupants.

Among its travels through the remainder of the 20th century and the early 21st century, FLIP was towed from San Diego to Barbados, drifted near the Hawaiian Islands, and was lashed by stormy seas off the Oregon coast. All the while, it provided exactly what Fisher and Spiess envisioned: a stable platform from which to make precise measurements at sea.

A Critical and Charismatic Buoy

The greatest challenge to measuring ocean properties has always been, well, being on the ocean.The beauty and genius of FLIP is that it isolates us from the ocean. The greatest challenge to measuring ocean properties has always been, well, being on the ocean. It is remote, dangerous, alternately cold and hot, wet, salty, and always moving. In an almost metaphysical way, this colossal steel tube allows humans to exist immersed within the ocean while protected from its tantrums.

The physical concept and engineering practice of deploying spar buoys for scientific expeditions were not novel in the early 1960s. But designing a spar buoy to hold scientific expeditions was a boundary-pushing step. The ambition and spirit that Fisher and Spiess captured in their design, which expanded over the platform’s decades of use, helped propel science, exploration, and discovery across the ocean sciences for more than half a century.

In my field of air-sea interactions alone, FLIP contributed to many discoveries. For example, it helped reveal how swells generated by distant storms travel across vast ocean basins, and it enabled scientists to make very accurate measurements of atmosphere-ocean transfers of energy and material (gas), information that remains widely used in numerical weather and climate prediction systems. More recently, scientists aboard FLIP directly measured fine-scale currents and wind patterns within centimeters to millimeters of the sea surface using techniques previously confined to controlled laboratory experiments.

In addition to being a supremely useful platform for scientific study, it was a charismatic buoy—and quite frankly, there are not many charismatic buoys. Simply put, it was interesting to think about, talk about, or just look at, and it left an impression on almost everyone who saw it, let alone on the “Flippers” who have been aboard during a flip.

Once, shortly after my time aboard FLIP, I launched into a lengthy explanation of my research when a man I was chatting with asked about my work. Seeing the glazed look come over his eyes (which speaks more to the quality of my explanation), I changed tack and just showed him a picture of FLIP to illustrate what I “do.” Immediately, his interest returned as he recognized FLIP and recounted how he had learned about it in his fifth grade science class. Indeed, FLIP was a tangible icon with which many in the science-interested public identified.

A Month Aboard a Most Unusual Platform FLIP is a very large spar buoy: It sits upright at the ocean surface and is specifically designed to respond minimally to surface wave motions. The author took this photo of FLIP’s “face” during the 2017 CASPER field study from the end of one of the platform’s three foldable booms, aptly named Face Boom. Credit: David G. Ortiz-Suslow

In October 2017, with a freshly minted Ph.D. in applied marine physics, I spent about 35 days aboard FLIP, and it definitely made a lasting impression on me as well. I was aboard as part of the science team for the U.S. Navy–funded Coupled Air-Sea Processes and Electromagnetic ducting Research (CASPER) program, which involved an interdisciplinary and international cohort of scientists from several academic universities and federal research laboratories. The scientific goal of CASPER was to better understand how the atmosphere and the ocean interact, as well as how this atmosphere-ocean coupling affects electromagnetic energy traveling in the marine environment. The CASPER science team had conducted a field campaign offshore North Carolina in 2015 and then commissioned FLIP for its West Coast campaign during fall 2017.

FLIP bobs; it does not translate. This difference in motion mitigates sea sickness yet leaves passengers with the uncomfortable sense that they’ve been marooned at sea.In some ways, being aboard FLIP was like scientific cruises aboard more horizontal research vessels. Ship life revolved around your watch, the designated period when you do the three primary shipboard activities: work, wait, and eat (sleep, the sanctified fourth activity, is done off watch). Also similar is how you are continually steeped in the aromas of fresh paint, burnt diesel, and brine.

However, in many other ways, time aboard FLIP is not like any other research cruise. FLIP bobs; it does not translate (i.e., move under its own propulsion). This difference in motion mitigates sea sickness yet leaves passengers with the uncomfortable sense that they’ve been marooned at sea. Also, all the livable space is vertically stacked, with hallways being replaced by ladders, which made simply going to bed a challenging multistep process.

After donning class IV laser safety goggles—because of the fascinating nighttime experiments your colleagues are running outside—and noise-blocking earmuffs, you climb down three exterior ladders, make your way through the generator room (hence the earmuffs), and maneuver onto a ladder extending down into the darkness of the spar, or tube, section of FLIP. Through a bulkhead hatch at the bottom of this ladder is yet another ladder to scale down—but don’t forget to first secure the hatch, quietly, without waking up sleeping scientists. Then, finally, you can climb into your own bunk and try to fall asleep to the sound of waves, hoping that you don’t have to use the head (bathroom) some 12 meters above you in the middle of the night.

Its peculiarities and inconveniences aside, FLIP was essential for achieving the objectives of CASPER because we needed a stable vantage from which to make measurements, which FLIP offered, especially compared with typical oceangoing ships. The data we collected from FLIP in 2017 have already given us new, fundamental insights into these physical processes.

For example, we are developing new tools to understand how electromagnetic signals propagate differently in various marine atmospheric conditions, techniques that are important for improved maritime communication and shipboard detection of low-flying objects for national security interests. We are also discovering how ocean internal waves leave distinct imprints on the atmosphere through complex and previously unknown mechanisms, and are getting a firmer grasp of the influence of ocean surface waves on atmospheric processes and atmosphere-ocean exchanges that regulate weather and climate. The CASPER team is also using our measurements to inform and validate sophisticated numerical models to help understand these processes and to generalize and translate our findings to other ocean conditions.

The Sun Sets on FLIP

My time aboard FLIP was short, but being part of the platform’s legacy has been a truly humbling experience.My time aboard FLIP was short, but being part of the platform’s legacy has been a truly humbling experience. Barring a major intervention, the fall 2017 cruise was FLIP’s last. In September 2020, the U.S. Navy ended its support of the platform, and its era of operational use came to an end. Although the pandemic was not the cause of this eventuality, it meant FLIP’s transition to emeritus status came without an opportunity for a public good-bye or any well-deserved fanfare.

Similar to the now defunct Arecibo Observatory in Puerto Rico, FLIP was a creation from a bygone era. Its drift into the sunset comes as research priorities and interests in the Earth sciences are shifting. FLIP was all steel and analog components, but the future will be built with lightweight alloys, carbon fiber, and autonomous systems. There is, of course, the understandable reality that exploring new horizons requires new technologies and that resources to support these explorations are finite.

In short, everything has an expiration date—not even a Hollywood credit helped Arecibo in the end. However, like its Boricua cousin of the planetary sciences, FLIP’s legacy goes beyond the innumerable discoveries it enabled, embodying human ingenuity, curiosity about the natural world, and the drive to witness its unperturbed beauty.

FLIP’s history and significance in oceanography are being actively discussed in the scientific community. My reflection here is only one perspective on a career that spanned decades and involved countless individuals. Given that my experience with FLIP came from its last chapter, I feel it is important to recognize the giant upon whose shoulders I and other researchers have stood. That giant comprised not so much the platform itself, but the engineers and shipwrights who designed, built, and maintained it; the venerable and irreplaceable Capt. Tom Golfinos, whose knowledge, memories, and stories weave an oral history of the past half century of developments in oceanographic science; and numerous full-time crew over the years, including David Brenha and John Rodrigues, who made the 2017 cruise possible. In spirit, if not by name, I would recognize the pioneering scientists who pushed the boundaries of oceanic exploration, inspiring the generations of scientists who followed them. These people and others made my time aboard FLIP possible—my time to bob above the ocean, watch the waves, and whoop as they passed—all without so much as a jostle or a wobble in my feet.

Author Information

David G. Ortiz-Suslow (dortizsu@nps.edu), Naval Postgraduate School, Monterey, Calif.

The coastal ocean is an extraordinarily energetic place where water and sediments are always in motion. More than a third of the human population lives near coastline globally, and we are collectively dependent on the coastal ocean for subsistence, commerce, and recreation. Rising sea levels and increasing intensity of storms are just two consequences of climate change that are influencing and will continue to influence the dynamics of coastal ecosystems. It is these dynamic physical characteristics and important mutual influences that make the coastal ocean critical to study but equally challenging to observe.

Miniaturized biologging devices can make oceanographic measurements and are suitable for small diving marine animals like seabirds.Oceanographers who study coastal ocean processes face a cost-benefit trade-off when planning sampling efforts. Surveys from oceanographic vessels provide opportunities to take measurements over broad areas, but time constraints, ship costs, and vessel drafts limit surveys. In contrast, instruments mounted on moorings can measure long-term time series, but only at discrete strategic locations. Autonomous underwater vehicles (AUVs) offer a mobile and continuous sampling approach, but AUVs are expensive to deploy and maintain, and strong currents, waves, and salinity gradients can reduce maneuverability or prohibit sampling through exceptionally dynamic regions.

Biologging—attaching miniature sensors to animals—is an emerging method for making long-term, low cost, and widely distributed autonomous measurements of the environment [Biuw et al., 2007; Harcourt et al., 2019]. Marine animals like seabirds and seals often access hard to sample locations, and they do so under their own power. Advances in data transmission and sensor technologies are facilitating the development of miniaturized biologging devices that can make oceanographic measurements and are suitable for small diving marine animals like seabirds.

Oceanographic Measurements from Cormorants

The Cormorant Oceanography Project, initiated in 2013, is advancing biologging tag technologies for use with cormorants to measure in situ oceanographic conditions. Cormorants and shags make up a family (Phalacrocoracidae) of about 40 species of birds that inhabit coastal oceans and inland waterways from the tropics to high latitudes. Marine cormorants typically forage along the seafloor at depths up to 80 meters, and they can make more than 100 dives each day. Between dives, cormorants rest on the sea surface, so their movements allow both water column and surface conditions to be measured with biologging.

The biologging tags we currently use are equipped with small, low-power, fast-response sensors to measure water temperature, conductivity (for water salinity levels), and pressure (for water depth). Each tag also features an inertial measurement unit (IMU) to monitor acceleration and orientation. A GPS unit, triggered when a bird surfaces, provides locations for georeferencing measurements, and solar cells recharge the tags’ batteries (at the time of writing, some tags have been transmitting continually for more than 2 years). The sensors collect large volumes of data that are transmitted and retrieved using two-way cellular communications. Cellular communications also allow us to transmit new sampling programs to the tags (Figure 1).

Fig. 1. The Cormorant Oceanography Project uses two-way cellular communications with biologging tags to relay data. While foraging, cormorants make consecutive dives and collect vertical profiles of temperature and salinity, and they provide depth soundings. GPS readings and accelerometer data collected between dives, when birds rest and drift at the surface, provide measurements of surface current velocity and surface gravity waves. Colored dots show water temperature data collected by a diving cormorant in the Columbia River estuary in 2019, where temperatures ranged from about 11°C near the bottom to 19°C at the surface. The data inset shows vertical velocity measured by an accelerometer in a tag deployed on a floating bird in the O. H. Hinsdale Wave Research Laboratory at Oregon State University. Credit: Vexels (flying cormorant image)

The data provide measurements from unsampled dynamic coastal marine environments, allowing us to improve model predictions.We are processing tag sensor data to obtain fundamental information about vertical temperature and salinity profiles, bottom soundings (which measure bathymetry), surface currents, surface gravity wave statistics (which characterize wave motions at the water-air interface), and air-sea temperature contrasts (which help us to understand ocean-atmospheric coupling). The data provide measurements from unsampled dynamic coastal marine environments, allowing us to correct uncertainties in boundary conditions and parameters of ocean models and thus to improve model predictions in a process known as data assimilation.

Processing bottom soundings obtained from pressure records gathered during cormorant dives requires disentangling bird behavior from the data. For example, we use dive shape to distinguish benthic (seafloor) dives from dives to intermediate water depths, which reduces uncertainty in the bottom sounding data.

For information about surface currents and surface gravity wave statistics, we use consecutive GPS fixes and high-frequency IMU measurements. Compiling this environmental information requires using the IMU data to distinguish active bird behavior (e.g., flying and paddling) from drifting passively on the ocean surface.

Measuring well-resolved temperature and salinity profiles is theoretically straightforward with data from diving birds, although engineering challenges remain. These challenges include designing a sensor housing that produces temperature measurements with a short response time and developing a small conductivity sensor that produces stable measurements for the duration of tag deployments. We are working with tag manufacturers to iteratively develop and test tag and sensor prototypes to improve profile measurement capabilities.

Finally, contrasts in air and sea temperatures can theoretically be measured at the beginning of dives when birds first submerge and at the end of dives when they surface. Precisely measuring air temperature is more challenging than measuring water temperatures, however, so improving determination of these contrasts is a long-term goal of the project.

Outfitting Cormorants in the Columbia River Estuary

Insights into Marine Bird Ecology

Cormorants, which forage in biologically rich nearshore areas, can be used as indicators of ecosystem health. In particular, cormorants tend to follow boom-bust cycles that track the availability of the fish they eat. Yet the specific ecological role of many cormorant species is unclear.

Like other predators, cormorants are often viewed as being in direct competition with humans, and they are vilified, persecuted, or simply ignored. The animal movement data collected through the Cormorant Oceanography Project, in tandem with oceanographic data, provide important basic information on the birds’ foraging ecology, distributions, and migrations. This information, in turn, is valuable for efforts such as marine spatial planning, in which human activities are coordinated to balance demands for development with the need to protect the environment.

In summer 2019, we fit 22 Brandt’s cormorants (Phalacrocorax penicillatus) captured from roosting sites near the mouth of the Columbia River, on the Oregon-Washington border, with biologging tags using backpack-style harnesses. At about 40 grams, these tags weighed less than 3% of a cormorant’s body mass, minimizing effects on the birds’ normal activities [Fair et al., 2010].

Brandt’s cormorants are fish-eating foot-propelled pursuit divers—meaning they chase prey—and are endemic to the California Current, a coastal ocean current flowing between British Columbia and Baja California. We found that Brandt’s cormorants are generally loyal to their roosting sites and foraging areas. The Columbia River estuary was their core habitat during the summer, but individual birds moved both north and south. Thus, our tagged birds collected concentrated data near the mouth of the river as well as along much of the Pacific coast of North America (Figure 2a), diving as far as 79 meters below the sea surface. This study allowed us to try out various tag types and collect oceanographic data to use in an assimilative model within a well-studied and highly dynamic estuary system (Figure 2b).

Fig. 2. (a) Cormorants tagged at the mouth of the Columbia River (near the Washington-Oregon state line) traveled long distances along the Pacific coast. About 325,000 dives by these birds (red dots) have been recorded to date. (b) Transect of temperature profiles (color-coded dots) collected by a bird at the mouth of the Columbia River during an ebbing tide over a period of about 1.8 hours. The bird reached the bottom at easting distances less than −2.2 kilometers, but not at easting distances greater than −2 kilometers. (c) Locations of water column profiles, color-coded by maximum dive depth, collected by tagged Brandt’s cormorants at the mouth of the Columbia River. More than 85,000 profiles have been collected in this region to date. Arrows indicate surface current velocities (the maximum shown here is 1.1 meters per second) estimated from the tagged birds, drifting at the surface between dives, along the transect shown in Figure 2(b). The inset shows a tagged Brandt’s cormorant. Click image for larger version. Credits: Adam Peck-Richardson (inset); National Geophysical Data Center (bottom depth and bathymetric contours).

Because of the birds’ autonomy in where and when they dive, the data they collect are heterogeneously distributed, making it difficult to interpret oceanographic information with analysis methods that require regular sampling intervals (e.g., averaging data over a long time at one location or performing a spectral analysis on a time series of data). Instead, we are applying techniques from inverse modeling and data assimilation and are using a numerical ocean model to fill gaps between data points and to infer ocean properties not directly observed.

The ability to estimate bathymetry from frequent, autonomous biologging measurements may have a practical utility for safe ship navigation and channel maintenance.For example, we are inferring seafloor bathymetry from our biologging data. Coastal bathymetry is often poorly known, and it is always changing. The mouth of the Columbia River is continually being filled in with sand, which forms unpredictable shoals and channels [Stevens et al., 2020], and annual dredging operations remove at least 1.5 meters of sediment from navigational channels to keep them safe for commercial shipping. The ability to estimate bathymetry from frequent, autonomous biologging measurements thus may have a practical utility for safe ship navigation and channel maintenance.

Instead of trying to determine the shape of the seafloor directly from the scattered data coming from the cormorants, we apply data inversion. First, we consider various model seafloor profiles using a method developed by Evensen [2009], in which a sample of randomly generated candidate bathymetries is run through a numerical model to obtain a least squares–based statistical relationship between these bathymetries and the observational surface current data [Wilson et al., 2010]. Then this relationship can be inverted (back-calculated) to estimate the bathymetry that best fits the real data.

We are currently testing this inverse approach for use with distributed biologged measurements of surface currents. In the future, we may use similar techniques to determine parameters other than bathymetry, such as the strengths of cold-water currents that upwell from the depths of coastal oceans, for which we could make use of temperature data collected by the cormorants.

Upgrading Tag Technology

Although the tags we have used to date have proven effective, continued advances in tag attachment methods, targeted sampling (recording data when birds are foraging or resting on the sea surface), and battery miniaturization, as well as in tag solar panels, sensors, electronics, and communications, would help to optimize biologging devices for improved data collection and for use with different species.

Several cormorants are seen here in silhouette. Continued technical advances are needed to optimize biologging devices for use with varying species. Credit: Adam Peck-Richardson

Biologging tags should be as small as possible relative to the mass of the animals carrying them, and they should be positioned to have negligible impacts on the animals’ energy expenditure as they fly or dive. Whereas high-latitude cormorants, including Brandt’s, tend to have larger bodies (2.5 kilograms), tropical cormorants can be as small as 360 grams, necessitating further tag miniaturization.

Furthermore, although the use of cell phone technology allows tags to transmit large amounts of data, data transmission is possible only in locations with cell phone coverage. The tags also require occasional electronic updates to keep up with consumer-driven advances in cellular technologies (e.g., 5G).

Finally, considering the birds’ autonomy, the biologging data they collect pose challenges to coordinating near-real-time data processing, archiving, and distribution. Maintaining data provenance, including measures of uncertainty associated with behavioral biologging data (as distinct from uncertainties in data obtained by conductivity-temperature-depth instruments), requires flexibility that has yet to be built into many oceanographic data repositories.

A Work in Progress

Since 2019, we have collected more than half a million dive profiles from three species of cormorants foraging in a range of near-shore habitats (Figure 3): In addition to the Brandt’s cormorants from the Columbia River estuary, we have fit biologging tags to pelagic cormorants to study the water near Middleton Island, Alaska, and to Socotra cormorants in the Arabian Gulf off the United Arab Emirates. We are now evaluating these data and comparing them to numerical models.

Fig. 3. Dive depths from biologging cormorants are indicated here by color-coded red dots, with species photos shown in the insets. (a) Eighteen pelagic cormorants (P. pelagicus) made 71,407 nearshore dives during a 2-week deployment near Middleton Island in the Gulf of Alaska in July 2020. (b) Eleven Socotra cormorants (P. nigrogularis) made 30,611 dives in the Arabian Gulf between November 2020 and January 2021. Credits: (a) Google Earth (shoreline), NOAA (bathymetry), Brendan Higgins (inset photo); (b) NOAA (bathymetry), Sabir Bin Muzaffar (inset photo)

Among other findings, these comparisons have revealed errors in models of temperatures for deep, cold ocean water that upwells to the surface, a common source of uncertainty in regional-scale ocean models on the U.S. West Coast. Future work will investigate other uncertainties about how coastal ocean environments function. For instance, we will use tag data from Socotra cormorants in the Arabian Gulf to diagnose sea surface temperature biases that occur in models and that are commonly associated with uncertain atmospheric forcing (e.g., the influence that dust storms exert on incoming shortwave radiation) [Lorenz et al., 2020].

Although we have made much progress in tag development, our near-term goals are to improve the response times of the temperature sensors we use, to test and improve our conductivity sensors, and to put smaller versions of these tags through trials. Over the next couple of years, we also aim to scale up our tag deployments through international collaborations and through the development of a global cormorant oceanography network. Furthermore, we are building an automated data pipeline through the Animal Telemetry Network to provide our biologging data to the oceanographic research community in near-real time.

With these efforts, we are continuing to expand the range of techniques and data that scientists have at their disposal to better understand highly dynamic—and highly important—coastal ocean environments.

Acknowledgments

The Cormorant Oceanography Project is sponsored by the U.S. Office of Naval Research. Dylan S. Winters (Oregon State University) processed the data for and produced Figures 1, 2, and 3. H. Tuba Özkan-Haller and Donald E. Lyons (Oregon State University), Reginald Beach (Office of Naval Research), and Christopher Wackerman (Naval Research Laboratory, Stennis, Miss.) provide project oversight and guidance. Sabir Bin Muzaffar (United Arab Emirates University) leads the tagging efforts for Socotra cormorants. The biologging tags we use were developed by Ornitela, Ornithology and Telemetry Applications, Vilnius, Lithuania. The 2014 data collection in the Columbia River was supported by Bird Research Northwest field crews, with special thanks owed to Daniel Roby, Yasuko Suzuki, Alexa Piggott, Peter Loschl, Kirsten Bixler, John Mulligan, and Anna Laws and with logistical assistance from Real Time Research. In 2019, efforts in the Columbia River were supported by Stephanie Loredo, Jason Piasecki, Emily Scott, Daniel Battaglia, Margaret Conley, Sam Stark, Tim Lawes, and Olivia Bailey (all at Oregon State University). Middleton Island data collection in 2020 was facilitated by Scott Hatch (Institute for Seabird Research and Conservation) and Jenna Schlener (McGill University), and field efforts were supported by Jillian Soller and Brendan Higgins (both at Oregon State University). Work with birds was approved by the Animal Care and Use Committee of Oregon State University, United Arab Emirates University, and the Office of Naval Research Bureau of Medicine and Surgery and by permits from the U.S. Geological Survey, Oregon Department of Fish and Wildlife, Washington Department of Fish and Wildlife, and Alaska Department of Fish and Game.

The near-Earth space is filled with charged particles that come from two sources, the solar wind and the Earth’s upper atmosphere. A new article published in Reviews of Geophysics investigates the relative importance of the two sources of charged particles and their effects on plasma dynamics, especially the process of magnetic reconnection, which is responsible of coupling the Sun magnetic field to the Earth’s magnetic field. Here the authors explain what ionospheric ions are, what we understand about them, and what there is still to discover.

What are ionospheric ions and where do they come from?

Up in the higher altitudes of the atmosphere is the ionosphere where there are increasing number of charged particles ionized by the Sun’s radiation. These “ionospheric ions” reflect the make-up of Earth’s atmosphere: ionized hydrogen, oxygen, nitrogen, and helium can all be found in this region of space.

Electromagnetic processes can give some of these ions enough energy to escape the Earth’s gravity potential, and magnetic field lines guide these particles in their journey to outer space, where they are further energized.

If that escaping rate remained constant, it would take around 1,000 billion years to deplete the atmosphere.Most of these particles do not go back to the atmosphere, and the net average escaping rate is roughly 5,250 tons per year.

This sounds like a large number, but it is actually a very small fraction of the Earth’s atmosphere. If that escaping rate remained constant, it would take around 1,000 billion years to deplete the atmosphere.

Although the loss of ionospheric ions is small, what impact do they have on near-Earth space?

The near-Earth space environment is known as the magnetosphere, i.e., the region where the Earth’s magnetic field dominates over the Sun’s magnetic field. The magnetosphere is like a magnetic bubble immersed in the heliosphere, the region where the Sun’s magnetic field dominates within the solar system. When certain conditions are met, the coupling between these two regions becomes very efficient, allowing large amounts of energy and particles from the Sun to enter the magnetosphere, generating geomagnetic storms and a variety of space weather phenomena.

The magnetosphere is constantly filled by particles from the solar wind and the Earth’s ionosphere.The magnetosphere is constantly filled by particles from two sources: the solar wind and the Earth’s ionosphere.

The relative contribution of the two sources is variable and roughly of the same order of magnitude, but their properties are quite different.

Solar wind ions entering the magnetosphere are composed mainly of H+ ions and a few percent of He++ ions. Ionospheric ions are initially cold, i.e., have lower thermal energy than the solar wind, and often contain large amounts of O+ ions in addition to the much lighter H+ ions.

Ionospheric ions circulate in the magnetosphere following magnetic field convection and are the origin of various magnetospheric populations, including for instance plasmaspheric plumes or the warm plasma cloak. These populations eventually reach the interface between the magnetosphere and the solar wind, i.e., the magnetopause, and change its properties. Therefore, depending on the time-history (hours to days) of the solar wind and the magnetosphere, the magnetopause changes its location and properties, potentially affecting the efficiency of the coupling between the two regions.

Artist rendition of the MMS mission orbiting in formation the Earth’s magnetosphere, to study its interaction with the solar wind. Credit: NASA/Goddard Space Flight Center (Public domain)

How have recent observations and models advanced our understanding of the behavior of ionospheric ions?

The NASA Magnetospheric Multiscale (MMS) mission has revolutionized our understanding of magnetic reconnection, the main process at work for coupling the Earth’s magnetosphere to the solar wind. Its spatial and time resolution has enabled us to understand how different charged particle populations are energized by the reconnecting magnetic fields.

Thanks to that mission, combined with high-performance numerical modeling, we now understand much better how ionospheric ions modify the reconnection process at a microphysical level. Ionospheric ions circulating in the magnetosphere are accelerated at reconnection sites and constitute a significant sink of energy for the reconnection process. In addition, depending on the ion mass, initial energy, and where the ions are entrained in a reconnection site, different energization mechanisms, some of them more efficient than others, come into play.

Main regions of the Earth’s magnetosphere. Ionospheric ions (light blue) escape and fill the outer magnetosphere until they exit the Earth space environment. Credit: Toledo-Redondo et al. [2021], Figure 1What are some of the unresolved questions where further research, data gathering, or modeling is needed?

We still understand relatively little about how magnetic reconnection microphysics shapes the magnetosphere system as a whole.We still understand relatively little about how these recent discoveries about magnetic reconnection microphysics shape the magnetosphere system as a whole.

The impact of cold ions is still an open field of research, as cold ions introduce a new length-scale and many plasma processes depend on the coupling between different scales.

The MMS dataset is continuously growing and only a portion has been extensively analyzed. Combining it with other mission datasets, such as for instance Cluster or THEMIS, to perform large statistical studies in the solar wind parameter space, will shed light about how the system reacts to ionospheric ions on a global scale.

Moreover, global 3D magnetospheric numerical models coupled to the ionosphere are very advanced nowadays and will also deepen our understanding of the global picture of ion circulation and energization in the magnetosphere in response to different kinds of solar activity.

There is yet another ionospheric population, which is even less understood: cold electrons. They also outflow from the ionosphere, and these are even harder to characterize than cold ions. Electrons play crucial roles on magnetic reconnection and wave generation in the magnetosphere. So far, because of the immense difficulty of observing these low-energy electrons, the effects of cold electrons remain largely unexplored.

Particle-in-cell simulation of magnetic reconnection, the main coupling process between the solar wind and the Earth’s magnetosphere. The color coding represents plasma number density. The magnetic field lines (solid black lines) break and reconnect at the Electron Diffusion Region, generating reconnection outflow jets. Credit: Toledo-Redondo et al. [2021], Figure 13—Sergio Toledo (Sergio.Toledo@um.es; 0000-0002-4459-8783), University of Murcia, Spain and University of Toulouse, France; Mats André (0000-0003-3725-4920), Swedish Institute of Space Physics, Sweden; Nicolas Aunai (0000-0002-9862-4318), Laboratoire de Physique des Plasmas, France; Charles R. Chappell (0000-0002-1703-6769) Vanderbilt University, USA; Jérémy Dargent (0000-0002-7131-3587), University of Pisa, Italy; Stephen A. Fuselier (0000-0003-4101-7901), Southwest Research Institute and University of Texas at San Antonio, USA; Alex Glocer (0000-0001-9843-9094), NASA Goddard Space Flight Center, USA; Daniel B. Graham (0000-0002-1046-746X), Swedish Institute of Space Physics, Sweden; Stein Haaland (0000-0002-1241-7570), Max-Planck Institute for Solar Systems Research, Germany, University of Bergen and The University Centre in Svalbard, Norway; Michal Hesse (0000-0003-0377-9673), NASA Ames Research Center, USA; Lynn, M. Kistler (0000-0002-8240-5559), University of New Hampshire, USA; Benoit Lavraud (0000-0001-6807-8494), University of Bordeaux, France; Wenya Li (0000-0003-1920-2406), National Space Science Center, China; Thomas E. Moore (0000-0002-3150-1137), NASA Goddard Space Flight Center, USA; Paul Tenfjord (0000-0001-7512-6407), University of Bergen, Norway; and Sarah K. Vines (0000-0002-7515-3285), Johns Hopkins University Applied Physics Laboratory, USA

Autonomous vehicles are jauntily steering through the streets of more and more cities, but the navigation systems in these vehicles remain an evolving technological concept. As companies vie for the rights to urban terrains, they typically use sensors based on optical properties (like light waves and video) or radio waves to map and navigate the environment. These options may not provide the best coverage, especially in bad weather. A team of researchers at the University of Michigan is turning to nature to develop something better.

“Animals have the amazing ability to find their way using sound,” said Bogdan Popa, an assistant professor of mechanical engineering at the university and principal investigator on the project. “We want to develop a sensor that uses sound like animals.”

Previous efforts with sound have failed because sound waves do not travel as far in air as light and radio waves. In fact, current ultrasound sensors have a range of only 1 meter and produce low-resolution maps.

Popa plans to leverage knowledge from nature to advance this technology.

Dolphins, bats, and whales use echolocation, a technique where a sound pulse is emitted into the environment. When the pulse encounters an object, it bounces off and sends reflections back to the animal to decipher. Using this approach, animals can navigate their terrain, find food, and avoid predators—all of which happens very quickly.

Popa believes echolocation offers a tantalizing new opportunity that will allow autonomous vehicles to operate in an uncertain world under inclement weather conditions while retaining their autonomy.

The Sensor of the Future

Sound has a limited range as it travels through the air. To propel sound waves more efficiently, Popa and his team constructed an acoustic lens using passive and active metamaterials.

Similar to an optical lens, the acoustic lens consists of two engineered pieces of patterned plastic that are capable of focusing ultrasonic sound waves (35–45 kilohertz) in any desired direction with only the slightest deformation. This capability means that the lens can be fixed to the vehicle and does not need to be cleaned or realigned. With only minor adjustments, the lens can project a focused wave in almost any direction. Popa likens this new sensor to a laser beam compared to traditional sound applications that are more like an incandescent light bulb.

The team also developed a process to analyze the vast amount of information contained in the returning echoes. To do this, they made the project even more multidisciplinary, turning to computer science to interpret biological sensory signals. The Michigan team developed a convolutional neural network, consisting of individual deep learning algorithms that can differentiate, weigh, and assign importance to self-labeled images.

“Using some experiments with dolphins to understand their behavior, we developed a series of neural networks,” said Popa. “Each neural network is specialized to recognize one object, like a type of fish, a threat, rocks, etc.”

For the first stage of the study, the team plans to develop a series of neural networks. Each network will be trained to interpret the returning echoes for a specific object and determine whether the object is present in the environment and its likeliest position.

“This is a modular approach that is more decentralized,” said Popa. “It is easier to do as opposed to one algorithm that has to provide all the data.”

Once identified, the object will be placed on the map in front of the vehicle. Popa plans to simultaneously map the environment with multiple neural networks to identify many different objects to recreate the world before the vehicle.

Next Steps

Once a network is trained, Popa believes it will be able to provide an answer to questions about location almost instantaneously. The team plans to layer neural network after neural network to provide the power of interpretation for an array of incoming echoes.

“For me, the most exciting part is understanding how the natural world does what it does in such an efficient way. We hope to replicate or equal the performance of these biological systems.”Although the team is still acquiring the data to train the various algorithms in the neural networks, they plan to test the system using virtual simulations. If all goes well, they will release the new acoustic sensor-based navigation system into the real world to see how it helps autonomous vehicles navigate the streets.

“Since this technology is still in the beginning stages, it’s hard to say how it will compare with current sensors,” said Teddy Ort, a Ph.D. candidate in the Computer Science and Artificial Intelligence Laboratory at the Massachusetts Institute of Technology. “If it could provide detailed 3D data at range, it could prove very valuable not only to replace, but perhaps to augment the current sensor suites.” Ort did not contribute to this study.

As the demand for autonomous vehicle technology increases, Popa’s contribution could improve the safety of vehicles navigating every community, large and small.

“For me, the most exciting part is understanding how the natural world does what it does in such an efficient way,” said Popa. “We hope to replicate or equal the performance of these biological systems.”

—Stacy Kish (@StacyWKish), Science Writer

Atmospheric levels of carbon dioxide (CO2) are the highest they’ve been in 800,000 years, and they are rising. Since the beginning of the Industrial Age, CO2 levels have increased nearly 50%. The consequences of increased levels of atmospheric CO2 are numerous and have far-reaching negative impacts, including on agriculture, climate, and human health, among others. To make matters worse, once CO2 is added to the atmosphere, it sticks around for hundreds to thousands of years.

Although increasing CO2 levels affect Earth and much of its life, plants are particularly sensitive to variations in these levels. They rely on the gas for survival, and changing carbon concentrations can affect everything from their growth rate to their nutritional value to their toxicity. Some hardy species are benefiting from current conditions, including an invasive plant known as famine weed (Parthenium hysterophorus). New research published in Nature Plants shows that one type of this toxic weed became more lethal under current CO2 levels, possibly making it more competitive and invasive.

Plants in a Carbon-Rich Atmosphere

“The question was, Why is one [famine weed biotype] spreading all over the place and the other is just kind of hanging out?”Famine weed is a flowering plant native to Central and South America but has become an invasive species in parts of Africa, Australia, and the Indian subcontinent. Interestingly, two biotypes of famine weed were introduced into Australia in the 1950s, but only one flourished in its new home.

“The question was, Why is one spreading all over the place and the other is just kind of hanging out?” asked Julie Wolf, a plant physiologist at the U.S. Department of Agriculture and the corresponding author of the study.

According to the international research team that examined how the increase in atmospheric CO2 over the past 170 years has likely changed the biochemistry of the two types of native famine weed plants, the answer lies in one of the organism’s less appealing traits. Famine weed produces a particularly nasty, carbon-based toxin called parthenin that prevents other plants from growing around it. It can also cause severe skin irritation and asthma in humans. This toxin is thought to contribute to the prolific spread of the plant by killing competing plants and possibly deterring predation.

“The current invasiveness and nastiness of [the invasive biotype] is probably being exacerbated to some degree by current CO2 levels.”At current CO2 levels, the invasive biotype produced more toxin by mass than the noninvasive biotype and more toxins than at preindustrial carbon levels, Wolf said. “The current invasiveness and nastiness of [the invasive biotype] is probably being exacerbated to some degree by current CO2 levels,” she said. With the increasing availability of carbon, it is easier for the invasive biotype to grow larger and produce more carbon-based toxin, possibly leading to its increased competitiveness, Wolf explained. The chemistry of the invasive biotype has probably adapted to use high levels of CO2 to its advantage, the authors say.

Focusing on the Future, Overlooking the Past

Further tests will be needed to see how famine weed fares as CO2 levels continue their upward climb, but the implications of its current adaptation are much broader. Danielle Way, a plant physiologist and associate professor at Western University who was not a part of the study, said this research illustrates that the selective pressure of the current level of atmospheric carbon may have already begun to favor carbon-adapted plants. These adaptations may have gone unnoticed because plant-response research has focused on future CO2 changes over the change we have already created.

“What have we already done to our system that is maybe passing under the radar because we’re really focusing on those even larger changes in CO2 and climate that we expect over the next 50 to 100 years?” Wolf asked. Unfortunately, the plants best equipped to thrive in these new conditions may not be the most beneficial to humans. “A plant that is successful in terms of persisting persists in the best way it can, and that might not match what we want from the plants,” said Wolf.

“A lot of times, people uniformly think that CO2 will be a benefit for plants, but it’s very much more diverse and varied.”That doesn’t mean only increased toxicity. Other research studying plant responses in even higher CO2 environments has found that for many food crops, although the size of the plant increased, its nutritional value decreased. When grown under high levels of CO2, species like wheat and rice end up with less protein and lower concentrations of micronutrients even though the individual grains can be larger in size.

Predicting exactly which plants will flourish in an increasingly CO2-rich world is difficult. “A lot of times, people uniformly think that CO2 will be a benefit for plants, but it’s very much more diverse and varied,” Wolf said. She hopes that this work will act as an alarm bell, pushing the community to investigate how plants have already changed in our current, carbon-rich atmosphere to learn what the future holds. Otherwise, we risk a planet rendered increasingly inhospitable not only by temperature and climate but also by the species we share it with.

—Fionna M. D. Samuels (@Fairy__Hedgehog), Science Writer

This piece was produced with support from the National Association of Science Writers’ David Perlman Virtual Mentoring Program.

On rotating planets, differential heating between the poles and the equator gives rise to instabilities. These are manifested as transient disturbances (e.g., Earth’s mid-latitude storms) that transport enthalpy poleward, thereby lessening the temperature gradients and quenching the instabilities. Scientists have long sought to understand how the resultant temperature gradients depend on the degree of destabilization, along with other properties of the system. Gallet & Ferrari [2021] develop a scaling law that quantifies these dependencies and shows how meridional temperature gradients respond – weakly – to changes in the forcing. Their scaling theory bounds the utility of the longstanding but ultimately incorrect hypothesis that eddies relax temperature gradients to a state of marginal stability. These new results provide a fully non-linear benchmark for numerical methods used to simulate geophysical flows, for guiding thinking as to the behavior of less idealized flows, and for inspiring aspiring theoreticians.  As Vallis [2021] points out in a companion Viewpoint, extracting order from turbulence is often seen as academic hardscrabble, which makes the fertility of Gallet and Ferrari’s accomplishment all the more remarkable.

Citation: Gallet, B. & Ferrari, R. [2021]. A quantitative scaling theory for meridional heat transport in planetary atmospheres and oceans. AGU Advances, 2, e2020AV000362. https://doi.org/10.1029/2020AV000362

—Bjorn Stevens, Editor, AGU Advances