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Urban Heat Islands Are Warming the Arctic

Mon, 04/13/2020 - 11:45

Urban heat islands—centers of warmth surrounded by halos of greening fueled by human activities—are an important climate phenomenon. Characterized by raised temperatures and longer growing seasons, these heat islands trigger significantly faster warming in cities than in rural areas. New research using satellite spectral imaging shows that urban heat islands aren’t just a product of metropolises in the planet’s populous temperate zones. They’re also contributing to climate change in the remote Arctic.

Igor Esau, an atmospheric scientist with the Nansen Environmental and Remote Sensing Center at the Bjerknes Centre for Climate Research in Bergen, Norway, has been gauging the impacts of urban heat islands (UHIs) across the Arctic with satellite observations of land surface temperatures and vegetation density. Reporting in Urban Climate, Esau and his Nansen Center colleague Victoria Miles used the Moderate Resolution Imaging Spectroradiometer (MODIS) to study 57 cities with more than 4,000 residents located above 64°N in Norway, Sweden, Finland, and northwestern Russia, an area known as Fennoscandia. This is the most urbanized part of the Arctic, and the area is expected to grow as the climate warms. The researchers found measurable UHIs surrounding every city in the region.

Satellite and thermal images of Noyabrsk, Russia (population 108,000), show the urban heat island effect, a difference between surface temperatures in urban and surrounding areas. Credit: Igor Esau and Victoria Miles, Nansen Environmental and Remote Sensing Center/Bjerknes Centre for Climate Research

The intensity of the UHIs, measured as the difference in land surface temperatures within and outside a 10-kilometer radius of a city, varies by season, location, and surrounding terrain. The strongest UHIs were seen in Murmansk, Russia, and Oulu, Finland, and ranged from +3°C to +5°C.

“When it accumulates, year after year, this lack of cold starts to change the environment, starts to change the soil properties.”In another study, to be published as a chapter in the forthcoming book The Arctic: Current Issues and Challenges, Esau and colleagues looked at 11 cities across the High North, including Fairbanks, Alaska; Tromsø, Norway; and Norilsk, Russia. Again, every city showed a strong and persistent heat island. Overall, including earlier studies of the Eurasian Arctic, western Siberia, and elsewhere, the researchers find that 70% to 80% of the Arctic towns and cities analyzed to date have significant UHIs, with 15% topping 3°C. The average temperature increase is +1.5°C.

That amount of additional warming may not feel like much in the Arctic, where winter temperatures can be −25°C or −30°C, Esau said in a recent presentation at the Arctic Frontiers conference in Tromsø. “But when it accumulates, year after year, then this lack of cold starts to change the environment, starts to change the soil properties.” Over time, that extra thermal output can lead to big environmental changes.

Urban Greening and Infrastructure Damage

The research finds the effects of Arctic UHIs are already apparent. “The most obvious impact is the so-called urban greening—a belt of more productive vegetation and more southerly plant communities in and around the cities,” Esau said.

Satellite observations measuring plant growth with the normalized difference vegetation index found cities surrounded by rings of abnormally verdant vegetation 2 to 3 times larger than the city itself. And places such as the Siberian taiga are now sprouting plants more appropriate to climates up to 600 kilometers south.The new research “makes us think about the impact of urban heat islands in the Arctic in the story of warming temperatures.”

“The other important impact is the declining soil stability and widespread infrastructure and building damage in the permafrost zones,” Esau said. As much as 80% of runways, roads, and other infrastructure in some parts of the Arctic have already been damaged.

The new Urban Climate paper is “a nice contribution on several levels,” said University of Alaska Fairbanks climate scientist Uma Bhatt, who was not involved in the study. “It makes us think about the impact of urban heat islands in the Arctic in the story of warming temperatures.”

Overall, the heat flux to the surrounding environment is up to 10 times larger per capita for Arctic cities than for temperate ones because of the Arctic’s long cold seasons and more compact urban footprint, Esau said. Current data sets severely underestimate the heat output of Arctic UHIs, which may reach 100 watts per square meter.

The Arctic, home to 4 million people, has warmed 3 times faster than the rest of the planet over the past half century, according to the January 2020 climate report by the National Oceanic and Atmospheric Administration and NASA. Arctic UHIs stand to warm the region even further, impacting the nearly 8 in 10 Arctic residents who live in cities experiencing more than 1.5°C of additional heating.

—Cheryl Katz (@ckatz99), Science Writer

Geohealth: Science’s First Responders

Mon, 04/13/2020 - 11:41

Geoscience During COVID-19 Geohealth: Science’s First Responders   Atmospheric Scientists Show Resilience in the Face of Lockdowns   Coronavirus Lockdown Brings Clean Air to Spanish Cities   During a Pandemic, Is Oceangoing Research Safe?

Last December, the outbreak of COVID-19 started as a localized event but quickly spread globally because of lapses in surveillance and preparedness. In this sense, the current pandemic reflects many disasters—such as the oil well blowout on Deepwater Horizon and the aftermath of the 2011 Tohoku earthquake and tsunami—which typically begin as singular events of limited harm but through a cascade of human and systemic errors end up having catastrophic impacts.

This pandemic is not the first and likely won’t be the last—Peter Daszak, an expert in disease ecology, has been warning us for years about zoonotic disease origination and the environmental pressures that cause viruses to leap into the human population. His contributions have greatly informed the discussion around how to stop the next SARS-CoV-2 (the virus that causes the COVID-19 disease) from emerging from the forests and rampaging the globe. Daszak is also one of the founding members of AGU’s journal GeoHealth (of which I am currently the editor in chief). Geoscientists have significant experience in disaster preparedness and disaster response, and a growing new community has been harnessing these skills in tandem with those of medical professionals, engineers, and social scientists to improve responses to events that have health, economic, and social impacts, including extreme events like pandemics.

The geohealth field emerged from the distinctive experiences of geoscientists who have collaborated broadly across disciplines to understand interactions between environmental processes and human health. Atmospheric chemist Mario Molina was part of the Nobel Prize–winning team that documented the links between chlorofluorocarbons (CFCs) and polar stratospheric ozone decline, leading to the Montreal Protocol and the international ban on CFCs. After accurately calculating the age of Earth from lead isotopes, geochemist Clair Patterson identified leaded gasoline as the main culprit of childhood lead poisoning and worked tirelessly and successfully to ban lead additives from fuel. Microbiologist Rita Colwell, the founding editor of GeoHealth, deconstructed the environment-disease interactions that drove cholera outbreaks and spearheaded low-cost local techniques to reduce cholera in drinking water. (Colwell was also the first woman to be named director of the National Science Foundation.) The geohealth community aims to bridge gaps between geosciences and health sciences and define a role for itself in breaking the cycle of disasters made worse through preventable human missteps.

A recent report noted the critical importance of involving scientists along with health professionals in crisis training exercises that would, ideally, make sure risk data are included in the creation of disaster plans.One key geohealth lesson we’ve learned again and again from disasters is the necessity for protections and adequate supplies for first responders. The Deepwater Horizon oil spill in the Gulf of Mexico killed 11 workers on the drilling platform immediately and went on to cause a generation of harm to the environment and to human health. The first responders to the spill were exposed to high quantities of very reactive and dangerous fresh hydrocarbons (these become somewhat more benign as they mature in the marine environment). A lack of adequate personal protective equipment (PPE) on-site combined with poor understanding of those health risks and the urgency of mitigating the disaster led to severe skin and breathing exposures for many first responders, along with prolonged illnesses that persisted for years.

The failure to learn from and implement changes based on this lesson is a tough one to see playing out again now with the shortages of testing kits, medical supplies, and PPE to help slow the spread of COVID-19. Similar to the Deepwater hydrocarbons, the virulence of SARS-CoV-2 was poorly understood at the outset of the pandemic, leading to early infections in health workers. No matter our level of understanding, first responders are always at higher risk of exposures to environmental hazards and viral pathogens. A recent report by Colwell and human ecologist Gary Machlis for the American Academy of Arts and Sciences noted the critical importance of involving scientists along with health professionals in crisis training exercises that would, ideally, make sure risk data are included in the creation of disaster plans.

The outcomes from the Deepwater Horizon disaster would have been markedly different if knowledge of the dangers of fresh hydrocarbons had bolstered PPE use and ensured that redundant mitigation equipment had been present. Similarly, if governments outside of China had involved scientists in national planning from the start, they would have been more aware of the potential for logarithmic growth in disease spread and thus of the need to produce and stockpile PPE for first responders, even if better quarantine procedures from the start meant they would not ultimately be needed.

The Tohoku event helped to catalyze the geohealth community to develop better early-warning systems for seismic hazards as well as tsunamis.Another lesson the geohealth community stresses is the need for adequate and accurate warning systems. For example, Japan has in place some of the most advanced construction standards for mitigating earthquake shaking, as well as widespread early-warning systems. Then the M9.1 earthquake centered at Tohoku shook the region in 2011. The earthquake early-warning system functioned well, but the safe zones and seawalls were designed and built to handle only inundations from tsunamis consistent with typical earthquakes in the region, not for a worst-case scenario event. Yet the 2011 tsunami was massive, with waves ranging from 10 to 40 meters high approaching at speeds of up to 700 kilometers per hour. The protective systems failed, and tens of thousands of people died. Scientists now know that an event like this is consistent with the paleorecord of tsunamic deposits in the region and could have been predicted and planned for.

The Tohoku event, along with the 2004 earthquake and tsunami at Sumatra, Indonesia, helped to catalyze the geohealth community to develop better early-warning systems for seismic hazards as well as tsunamis. These tools capitalize on mobile technologies to give real-time warnings, thus saving lives. In the context of COVID-19, early warning means having test kits available. The logarithmic growth prediction coupled with rapid vector transport via air travel should have led to massive production and distribution of tests so that we could pinpoint and isolate emerging hot spots. The assumption that the spread of this disease would fizzle before becoming globally widespread, as the SARS outbreak did in 2003–2004, is akin to that about the size of potential tsunami events prior to Tohoku—and it’s an assumption that has resulted in the pandemic we see today.

Finally, risk messaging has to be sound and consistent throughout a disaster. As geohealth experts have recognized from the Deepwater Horizon and Tohoku events, stress and anxiety during disasters drive a host of short- and long-term pathologies that extend to physical health. The key to mitigating these effects is to analyze the progress of a disaster using sound science and provide science-informed recommendations to citizens so that they are—and feel—prepared.

The geohealth community is already mobilizing to understand COVID-19 dynamics and its secondary impact on health and environment.When the Tohoku tsunami led to the meltdown of several reactor cores at the Fukushima Daiichi Nuclear Power Plant, the messaging about health impacts of the resulting radiation hazards was inconsistent, inaccurate, and purposefully optimistic. The immediate monitoring performed to assess the amount and distribution dynamics of radiation released, which are influenced by topography and atmospheric circulation, was not nearly sufficient. And the regulatory agencies responsible for the assessments simply drew concentric circles around the release site representing varying risk levels. It was not until a loose coalition of citizen scientists took up the task that there was any documentation of the highly variable radiation distribution across the region. Meanwhile, the regulatory agencies first downplayed the risks, then provided inconsistent enforcement of no-travel radiation zones that were not science based and that changed daily.

Research on the societal stress this poor messaging caused has led to new approaches to engaging communities in risk messaging. These are lessons we should be executing today. We know enough about viral dynamics and pandemic spread to accurately and consistently inform the public about infection avoidance and risk. Using the geohealth community’s approach to messaging would help relieve public anxiety while still containing the outbreak.

The Deepwater Horizon and Tohoku events are examples of experiences from which the geohealth community has learned to better plan for and respond to disasters and to better inform communities, cities, and governments about best practices. Our community is already mobilizing to understand COVID-19 dynamics and its secondary impact on health and environment. Geohealth researchers are dedicated to documenting links between infectious disease, climate, human migration, risk communication, and system responses—lessons learned from making these links can help efforts to handle early stages of a disaster and keep it from growing. Even amid a pandemic, it’s not too late to start adopting these lessons and, we hope, to avoid a next time.

—Gabriel Filippelli (gfilippe@iu.edu), Center for Urban Health, Indiana University–Purdue University Indianapolis; Editor in Chief, GeoHealth

Air Pollution Can Worsen the Death Rate from COVID-19

Fri, 04/10/2020 - 16:49

As the United States struggles to contain the coronavirus epidemic, scientists are finding that air pollution is making things even worse. In a study submitted for publication, researchers at Harvard University found that even a small increase in long-term exposure to PM2.5, or particulate matter with a diameter of 2.5 micrometers or less, can lead to a large increase in the death rate from COVID-19, the illness caused by the novel coronavirus.

Air Quality in a Time of Crisis

With over 460,000 cases in the United States, coronavirus-related deaths are approaching 20,000 and could reach about 60,400 by early August, according to the latest projection from the Seattle-based Institute for Health Metrics and Evaluation. Although the mechanisms of COVID-19 are still being investigated, the World Health Organization reported that one in seven patients develops difficulty breathing and other severe complications.

PM2.5, meanwhile, has been associated with health problems such as premature death, heart attacks, asthma, and airway irritations. However, in March, the Environmental Protection Agency said it was relaxing air pollution enforcement rules and allowing power plants, factories, and other facilities to skip pollution tests.

Scientists have long known about the effects of air pollution on public health. A severe smog event in London in 1952, for example, is believed to have caused about 12,000 deaths. Four years later, the United Kingdom’s Clean Air Act came into force and prohibited burning polluting fuels in designated areas, setting the stage for similar legislation overseas.

Researchers determined that an increase of only 1 microgram per cubic meter of PM2.5 is associated with a 15% increase in the COVID-19 death rate.The researchers from Harvard’s T.H. Chan School of Public Health noticed that many conditions known to contribute to more severe COVID-19 outcomes are also known to be caused by long-term PM2.5 exposure. Seeking possible connections, they used an environmental health data platform they had already compiled that featured nationwide PM2.5 and socioeconomic and demographic information. They then added the incoming COVID-19 outcome data to the mix.

They analyzed data from 3,080 counties in the United States; adjusted for variables including population size, number of people tested, weather, obesity, and smoking; averaged PM2.5 exposure over 2000–2016; and looked at COVID-19 deaths as the outcome. The data account for 90% of confirmed COVID-19 deaths in the United States as of 4 April 2020. In the study, which has been submitted to the New England Journal of Medicine, the researchers determined that an increase of only 1 microgram (μg) per cubic meter (m3) of PM2.5 is associated with a 15% increase in the COVID-19 death rate.

“We found that people living in counties in the United States that have experienced higher levels of air pollution over the past 15–20 years have a substantially higher COVID-19 mortality rate,” said study coauthor Rachel C. Nethery, an assistant professor of biostatistics at Harvard. “Based on our findings, we would expect a county with PM2.5 levels of 15 μg/m3 (highly polluted) to have approximately 4.5 times higher COVID-19 death rate than a county with PM2.5 levels of 5 μg/m3 (low pollution), assuming the counties are similar aside from the difference in pollution levels.”

Relaxing Rules the “Wrong Choice”

The results of the study, which is the first nationwide report of its kind in the United States, are not surprising given epidemiological findings on air pollution for diseases such as severe acute respiratory syndrome (SARS), but the effect of PM2.5 on mortality could be dramatic, said University of Southern California environmental epidemiologist and biostatistician Zhanghua Chen, who was not involved with the study.

“The current EPA’s action on the relaxation of environmental rules in terms of pollutant emissions from power plants, factories, and other facilities is an obviously wrong choice and could result in more COVID incidences and deaths.”“Even though the findings were based upon the ongoing development of the pandemic and we cannot exclude the possibility that there are potential confounders that are not adjusted for, the findings of this paper lay out straightforward information that we should make all efforts to improve air quality so that we can reduce the total number of deaths from disasters like COVID-19,” said Chen. “The current EPA’s action on the relaxation of environmental rules in terms of pollutant emissions from power plants, factories, and other facilities is an obviously wrong choice and could result in more COVID incidences and deaths.”

Nethery said many people have been asking how they can limit the harmful impacts of air pollution during the epidemic. Her team plans to examine the effects of short-term air pollution exposure in COVID-19 as well as the disease’s relationships with race and poverty.

—Tim Hornyak (@robotopia), Science Writer

Arctic Coast Erosion Linked to Large-Scale Climate Variability

Fri, 04/10/2020 - 11:30

The Arctic is warming more rapidly than any other region on earth. The increased temperatures lead to decreased sea-ice coverage both in concentration and in duration. This has a profound effect on the coastal margins of the Arctic as they are subject to warmer air temperatures and exposed to more ocean waves that act to thaw the previously frozen permafrost soils. The coastal erosion of permafrost releases vast amounts of previously stored carbon that then may exacerbate climate change thereby creating a vicious cycle.

Key observational monitoring sites in the Laptev Sea of the Arctic have been maintained for almost 30-years and offer a rare insight into how coastal erosion rates vary in response to regional drivers. Nielsen et al. [2020] find that most of the coastal erosion variability can be attributed to changes in the length and concentration of the winter sea ice coverage as well as changes in the large-scale atmospheric wind and air temperature patterns associated with the Arctic Oscillation climate mode.

Somewhat paradoxically, this is promising news for the relatively coarse-resolution Earth System Models (ESM) and that have largely neglected the role of Arctic coastal erosion in the carbon cycle.  With typical grid scales of 100s of kilometers, ESMs are inherently better equipped to improve their representation of the large-scale drivers of the Arctic climate variability rather than the small-scale features of the coastal erosion itself.

Citation: Nielsen, D. M., Dobrynin, M., Baehr, J., Razumov, S., & Grigoriev, M. [2020]. Coastal erosion variability at the southern Laptev Sea linked to winter sea ice and the Arctic Oscillation. Geophysical Research Letters, 47, e2019GL086876. https://doi.org/10.1029/2019GL086876

—Janet Sprintall, Editor, Geophysical Research Letters

Walter C. Pitman III (1932–2019)

Fri, 04/10/2020 - 11:30
Walter Pitman addresses a Lamont-Doherty awards ceremony in 2001. An image of famous marine cartographer Marie Tharp appears in the background. Credit: Lamont-Doherty Earth Observatory, Columbia University

Walter C. Pitman III, a deeply influential figure in the generation of scientists that established plate tectonics as the ruling paradigm for understanding Earth history, died on 1 October 2019 at age 87. He left his fingerprints all over the “first draft” of plate tectonics research. Many of us now take small steps to advance understanding in this field by honing the insights that Walter first established.

The son of determined parents, Walter grew up on a small farm in New Jersey, where he learned to repair farm equipment, tend to the family garden, and work on projects such as converting the family Model T Ford into the farm’s tractor. For most of his life, though, he was a New Yorker through and through, sharing the honesty and directness of many of his fellow residents.

Walter’s early years did not portend the success he would find at Columbia University’s Lamont-Doherty Earth Observatory, where he spent his entire career. Walter attended Dartmouth College but was invited to leave after his freshman year, probably because he loved life a bit too much for the Ivy League. He earned his first degree in electrical engineering at Lehigh University in 1956, then took up work with the Hazeltine Corporation at a plant that produced sonobuoys used for acoustic detection of submarines. (He later encouraged Lamont to use these sonobuoys in marine seismic refraction experiments.)

Polykarp Kusch could not have known the gift he gave to the study of geomagnetism by redirecting Walter’s enthusiasm toward marine geophysics.Walter considered earning a degree in physics that he thought would enable him to participate in the amazing ongoing discoveries concerning the nature of matter and energy. But, as he often liked to relate, Polykarp Kusch, Nobel laureate and chair of Columbia’s Physics Department, once told him, “Walter, you just are not smart enough to achieve great things in physics; I suggest that you speak to Jack Nafe,” referring to the esteemed Columbia professor of geophysics.

Although Kusch could measure the anomalous magnetic moment of the electron, he could not have known the gift he gave to the study of geomagnetism by redirecting Walter’s enthusiasm toward marine geophysics. Walter contacted Nafe at what was then called the Lamont Geological Observatory. Nafe recognized and valued Walter’s engineering skills and his enthusiasm for science. Walter sailed on the R/V Vema for nearly a year as a marine technician before being called home to begin graduate school at Columbia.

A Fabric of Understanding

Walter was a great synthesizer of scientific ideas. He delighted in weaving a fabric of understanding about Earth from diverse observations. As a young researcher, Walter quickly recognized the significance of a newly acquired long magnetic anomaly profile over the southeast Pacific spreading center. The profile, collected on the USNS Eltanin in 1965, revealed the symmetry of the magnetic anomalies across the ridge axis.

Walter and his colleagues used these data to establish seafloor spreading as the prevailing mechanism for continental drift. Further application of the insights gained from these data helped define the 150-million-year history of geomagnetic field reversals, the formation of the Atlantic and Pacific ocean basins, the tectonic evolution of the Alps, and the role of changing sea level in controlling sediment accumulation on continental margins.

The story of the Eltanin 19 profile is well known, but Walter would occasionally add an epilogue about going, with some trepidation, to show the data and explain his conclusions to Lamont’s director, Maurice “Doc” Ewing. Ewing was famously opposed to the new theories being established with the data collected on Lamont’s ships. As Walter told the story, Ewing nodded appreciatively during his presentation. When it was over, Ewing had one recommendation for Walter: “If this is proved wrong, be sure you are the one who publishes the refutation.” This was simultaneously good career advice and wishful thinking.

Tracking Noah’s Flood

Walter enjoyed the way that his early advocacy of the concept of seafloor spreading had challenged the notions of mentors during his early career.The history of postglacial sea level change led to Walter’s work with his Lamont-Doherty colleague Bill Ryan on the biblical era flooding of the Black Sea. They argued in a 1998 book that this event was the source of the flood story of Noah and his ark, positing a cultural diaspora of those displaced by the drowning of their homes.

Walter delighted in the disruption this introduced into the archaeological community, much as he enjoyed the way that his early advocacy of the concept of seafloor spreading had challenged the notions of mentors during his early career. Some researchers welcomed the structure that this hypothesis provided to isolated observations from independent archaeological studies, but it was vigorously disputed by others. As always, Walter enjoyed the argument.

Generosity, Good Humor, and Good Stories

Walter was an extremely generous person in many ways. Walking with Walter on the streets surrounding his apartment near Columbia was a unique experience. The doormen and homeless alike always engaged him. He returned their interest, stopping to discuss the events of the day and leaving a little cash in the palms of the needy. He was generous too in supporting his colleagues and in mentoring students, all of whom benefited from Walter’s interest and enthusiasm. He never seemed to be in a hurry. He always had time to talk.

Walter loved science, he loved Lamont, and he loved his life at sea, and conversations with him were peppered with humor and stories of his experiences.Walter loved science, he loved Lamont, and he loved his life at sea, and conversations with him were peppered with humor and stories of his experiences. Though he won many important awards—and appreciated the recognition—one of his charming characteristics was an inability to take himself seriously. The plaques and medals he received remained stacked on his office windowsill, where they collected dust as he moved on to his next interest.

In his later years, Walter suffered from short-term memory loss. This did not diminish his enthusiasm for old friends or his delightful and educational stories. He remained uniquely himself. Walter C. Pitman III lived a long and productive life. He will be remembered for his essential scientific contributions, and he will be held dear in the hearts of those who were privileged to work with him or meet him.

—Bernard Coakley (bjcoakley@alaska.edu), Department of Geosciences and Geophysical Institute, University of Alaska Fairbanks; Steven Cande, Scripps Institution of Oceanography, La Jolla, Calif.; and John LaBrecque, Center for Space Research, University of Texas at Austin

Carbon Cycling in the World’s Deepest Blue Hole

Fri, 04/10/2020 - 11:30

In the South China Sea, the Yongle blue hole was recently found to be the deepest blue hole on Earth, reaching 300 meters down—deep enough to submerge the Eiffel Tower. A blue hole, essentially a marine sinkhole with an opening to the sea surface, forms a natural laboratory where scientists can research patterns that are harder to detect in the unsheltered waters of the open ocean.

Blue holes are usually circular pits with steep walls. Tides wash over their tops, but their unique structure keeps the environment deep inside relatively isolated. As a result, blue holes can have unique microbial communities, sediment archives, and chemical gradients. Yao et al. tested the waters of the Yongle blue hole to learn more about its carbon cycling processes, which are not often studied in blue holes.

The researchers found the lowest concentrations of dissolved organic carbon ever recorded in coastal waters. At the same time, they found some of the highest concentrations of dissolved inorganic carbon in similar conditions. Both the organic and inorganic carbon molecules were much older than carbon found at parallel depths in the open ocean.

The scientists concluded that the carbon cycling process in this blue hole depends strongly on the natural gradients found in its depths; between about 80 and 100 meters, dissolved oxygen disappears, and salinity, temperature, and pH all change sharply. They attribute the bulk of carbon cycling in this blue hole to the processes of the microbes that live there, including sulfur cycling and methane production. The role of carbonate dissolution from the walls of the blue hole in affecting the ages of carbon in this system remains uncertain, yet there appears to be no evidence of inflow of subterranean fresh water into the bottom waters of the blue hole.

Blue holes allow scientists to study chemical gradients with a precision impossible in the open ocean. As marine environments around the globe experience growing patches of low oxygen, understanding these gradients and cycles is more important than ever. Further, the amount of dissolved inorganic carbon in the hole seems to be increasing, so blue holes may become a carbon dioxide source that must be factored into wider climate change and blue carbon predictions. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2019JG005307, 2020)

—Elizabeth Thompson, Science Writer

This Week: Guilty Pleasures to Get You Through Quarantine

Fri, 04/10/2020 - 11:28

Candy. I’ve been on a sugar high as early as 10:00 a.m. —Anonymous

 

Primal Scream. Eight o’clock p.m. is the primal scream in my neighborhood, when children, parents, college students, and teleworkers open their windows and let out a guttural howl into the night sky. I don’t like to miss this daily ritual in my D.C. neighborhood, and I find it oddly calming how the shouts of the young and the old, the brash and the timid, all blend into a collective bellow. According to the New York Times, we’re not the only ones. —Jenessa Duncombe, Staff Writer

 

Sir Pat Reading Shakespeare.

Tweets by SirPatStew

Leave the guilt right out and experience the pleasure of listening to the mellifluous Patrick Stewart read Shakespeare’s sonnets. —Tshawna Byerly, Copy Editor

 

Pilot Peter’s Season of The Bachelor: #TeamHannahAnn. While the New York health department is cautioning the public with articles such as “Quarantine and Chill: How New Yorkers Are Mating and Dating During Coronavirus,” I have been filling my nonwork time with nature walks (avoiding people); drinking beer (thank you, home delivery services); having coffee on the lanai; and binge-watching Zoey’s Extraordinary Playlist. This show is so much more enjoyable than the ever-so-disappointing finale of Pilot Peter’s season on The Bachelor. #TeamHannahAnn —Melissa Tribur, Production Specialist

 

Pet Pics.

Complying with our stay-at-home orders…dogs help make it better. Share your pet photos and how they are helping with your #geoscienceathome pic.twitter.com/be1wB8qqjB

— American Geophysical Union (@theAGU) March 30, 2020

Yeah, I said it. Last week a coworker shared the very important information that her cat has a habit of licking the blinds behind her desk during video meetings and followed up with an email to a dozen of us with camera evidence. That thread quickly turned into a daily pet picture update that is both an adorable interruption to my day (c’mon, look at this good girl) and a lovely way to stay a little bit connected to several people I don’t otherwise work with and used to catch up with only in common spaces at the office. Go ahead, start a pet thread. You won’t regret it. —Anonymous

 

Roll D20 to Make a Sanity Check. My weekly social interaction comes from our Dungeons and Dragons campaign, which, to be fair, started in person before the pandemic shut down the world. There are some really nice D&D sites that let your whole group log on, video chat, and interact with a virtual game board. It’s been a wonderful escape and a way to work out my anger and aggression as a level 5 Dragonborn fighter beating up monsters and trying to keep our Damsel in Distress from being kidnapped by the Evil Overlord. Life is so much simpler when you can kill it with a sword. —Anonymous

 

Making the Cut.



I don’t follow the fashion industry, and nobody would mistake me for being fashionable. But I do appreciate the artistry and craft of designers and clothing makers, and I’ve been an avid fan of Project Runway—and especially longtime show mentor Tim Gunn—for years. So I eagerly anticipated the late March debut of Making the Cut, a new project from Gunn and original PR host Heidi Klum that’s been in the works since the pair departed PR a couple of years ago. There have been only a few episodes so far, so it remains to be seen whether MtC will prove to be an upgrade over its progenitor. My initial impression: The contestants are compelling and talented, but MtC seems to replace some of PR’s wit and substance for snark and show. Nonetheless, it mostly scratches whatever fashion itch I have, especially with PR currently between seasons. —Timothy Oleson, Science Editor

 

Spinach Dip. I discovered how delicious homemade spinach dip is, and how easy it is to make it. I hope the stay-at-home order ends soon because I’ve gained 4 pounds. My simple recipe: Chop celery into very small dice (or use chopped water chestnuts) and combine with equal parts of sour cream, mayonnaise, and Greek yogurt. Add desired quantity of spinach that you’ve steamed, squeezed dry, chilled, and chopped (or use frozen spinach). Add dry Lipton or Knorr vegetable soup mix to taste. Mmm, delicious! —Don Hendrickson, Copy Editor

 

Vampires and Reavers and a Ph.D. in Horribleness. Yeah, I don’t feel guilty about this one. I’ve been taking comfort in rewatching old favorites by Joss Whedon during my extended stay at home. We just finished up season 2 out of seven of Buffy the Vampire Slayer (nothing better than the original Scoobies, in my opinion), and then we’ve got Angel, Firefly (and Serenity, duh), Dollhouse, and whatever else we can get our hands on. And no rewatch marathon would be complete without the beauty of Dr. Horrible’s Sing Along Blog. *I’m a leaf on the wind….* —Kimberly Cartier, Staff Writer

 

Fanfic. Better than canon. Fight me (anonymously). —Anonymous

 

Of Bread and Binges. Gosh, there’ve been a lot over the past month….My two very bad cats are happy that I’m home more (I think), and I don’t feel guilty about spoiling them one bit. I’ve enjoyed preparing all my own food, but my willpower has gone out the window—I ate an entire loaf of banana nut bread over one weekend! I won’t tell you what Apple’s Screen Time has been reporting, but I’ve binge-watched some really bad shows (Tiger King on Netflix) and some excellent ones as well, such as HBO’s Parade’s End and Amazon’s Fleabag, and there are gems on social media that brighten my days, such as Yo-Yo Ma’s #songsofcomfort:



—Faith Ishii, Production Manager

 

The Three-Body Problem Trilogy. I devoured this series by Chinese sci-fi writer Cixin Liu. The Hugo Award–winning first installment begins with the discovery of a signal of alien intelligence. What should humanity do? The series unfolds in a truly mind-bending epic that manages to span millennia while still caring for the lives and details of each person who carries the story through to its satisfying (I thought) end. Liu wrote the first book in 2006, but the series became available to English readers only when it was translated a few years ago. I borrowed The Three Body-Problem as an e-book from the D.C. Public Library (find your local library here), and the whole series can be found on both e-book and audiobook (or check whether your local bookstore can help), so you can enjoy it all without even breaking self-isolation. —Heather Goss, Editor in Chief

 

Schitt’s Creek.



I’m way late to this party, I know, with the show wrapping up its sixth and final season this past Tuesday, but I’ve been LMAO’ing my way through the early seasons of Schitt’s Creek lately. Seriously, how’d I sleep on this show for so long? The cast, from top to bottom, is pure gold. —Timothy Oleson, Science Editor

 

Up on the Roof. The roof of my house isn’t exactly meant to be sat on…it’s slightly tilted and has a sandpaper-like texture. But thanks to a ladder, an escape hatch, and a yoga mat, it’s my frequent escape from a crowded indoor living situation. The fair spring air and the occasional cardinal aren’t bad either. —Anonymous

Credit: National Archives

 

 

 

 

Second Sleep.

That wonderful WPA poster may be on to something. Before the Industrial Revolution, peasants like us used to sleep in two shifts (biphasic sleep, ahem). I’ve rediscovered long afternoon naps, late-night TV binges, and a surprisingly decent work ethic. —Caryl-Sue, Managing Editor

Coronavirus Lockdown Brings Clean Air to Spanish Cities

Thu, 04/09/2020 - 12:37

Geoscience During COVID-19 Geohealth: Science’s First Responders   Atmospheric Scientists Show Resilience in the Face of Lockdowns   Coronavirus Lockdown Brings Clean Air to Spanish Cities   During a Pandemic, Is Oceangoing Research Safe?

Air pollution levels have dropped dramatically in Spanish cities because of measures adopted by the government to fight the spread of the novel coronavirus (COVID-19). These measures include mandatory confinement of the population, reduction of industrial activity, and strict limitations on the use of private vehicles.

Spanish authorities declared a state of emergency and mandatory confinement of the population on 14 March. Schools had been closed 2 days earlier, on 12 March. Two weeks later (on 30 March), amid growing rates of contagion and COVID-19-related deaths, the government enforced the stop of all nonessential industries and activities.

Just a few hours after the declaration of emergency, pollution levels in Spanish cities started to decrease. Within a week, record-low levels of nitrogen dioxide (NO2) concentrations were measured in the 10 largest cities in the country, with levels averaging 64% lower than in the previous week.

NO2 is routinely monitored in European cities, as it serves as a proxy for traffic pollution. This gas forms in high-temperature combustion in gasoline and diesel vehicles, and its concentrations respond quickly to changes in traffic density. NO2 can cause lung damage and irritate the eyes and respiratory tract. It’s also related to the formation of acid rain.

To track these changes, a team of researchers from Spain’s Universitat Politècnica de València (UPV) analyzed images from the European Space Agency’s Sentinel-5P satellite. Launched in 2017, Sentinel has enough resolution to monitor pollution levels at the neighborhood scale. On the basis of these data, the researchers have generated a series of maps that show the concentrations of NO2 in principal Spanish cities.

The satellite data revealed that the highest reduction occurred in Barcelona on 16 March, with NO2 concentrations of 10 micrograms per cubic meter of air, 83% lower than the previous week. Such levels haven’t been recorded in at least 20 years. Barcelona was followed by Castellon (76% lower) and Madrid (73% lower). NO2 levels in Madrid and Barcelona are routinely above 40 micrograms per cubic meter, which is the maximum allowed by environmental regulations in the European Union.

Satellite data reveal the reduction of NO2 emissions in Spain during the COVID-19 pandemic. Credit: Elena Sánchez-García/UPV

“We were expecting to see similar results to the studies that have been made in China and Italy, but it’s still surprising,” said Elena Sánchez-García, a researcher at UPV and one of the scientists leading the effort to analyze the data of the new study. “These are preliminary results that will be updated in the following weeks.”

A World Without Traffic

Everything points to traffic reduction as the main culprit for the steep reduction in air pollution levels.Everything points to traffic reduction as the main culprit for the steep drop in air pollution levels. Right after the lockdown started, the number of vehicles on the road declined by 90%. Fuel sales fell 83% for gasoline and 61% for diesel from the previous week, according to the Spanish Ministry of Transport.

The UPV team has also looked at other pollutants, such as carbon monoxide and sulfur dioxide, which are also measured by Sentinel-5P, but the reductions aren’t as clear as they are for NO2, likely because other gases stay in the atmosphere for a longer period of time.

The dramatic reduction in atmospheric pollution shows the heavy impact that traffic has on urban air quality. “What we consider is that it’s actually possible to reduce air pollution to a large extent,” said Mark Nieuwenhuijsen, an expert in air pollution and urban planning at the Barcelona Institute for Global Health. “As you can see, if you take an important source [of air pollution] away, air pollution really decreases.”

The air pollution reduction could come as a beneficial side effect in the fight against the novel coronavirus. According to Nieuwenhuijsen, recent evidence points to a slower spread rate in cities with clean air, although the mechanism that produces the correlation is unknown. One possibility is that the viruses could hitch a ride in suspended pollution particles and thus remain in the air for longer periods and spread faster. Another possibility is that air pollution can weaken our natural defenses against infection. For instance, high air pollution levels can damage the lungs, making it easier for the virus to go through the lung’s epithelium.

To help unravel the relationship between the evolution of the pandemic and pollution levels, the European Union Earth Observation Programme has created a website with constantly updated information on pollution levels, maps, and forecasts for 50 major European cities that could be useful to researchers.

Pollution and Risk

The radical measures taken by governments worldwide to protect their populations from the coronavirus are also telling of how human societies respond to other health hazards.

“I think one of the reasons [the coronavirus response has been more immediate] is that with the virus you can see who actually dies, whereas with air pollution it is not so clear; it’s a lot about statistics,” Nieuwenhuijsen said. “We know that in Barcelona, 600 people per year die as a result of air pollution, but you don’t know exactly who the person who died from air pollution is.”

In Barcelona alone, the combination of air pollution and noise caused by traffic prematurely kills more than 1,000 people every year. A long list of health concerns, including child asthma, sleep alterations, mental health issues, cognitive decline in the elderly, and developmental issues in children, are related to traffic. However, they don’t prompt the same kind of swift and costly response that a threat perceived as imminent does.

“I’m hoping that there’s going to be an economic stimulus plan after this, and I hope it will account for the environmental consequences,” Nieuwenhuijsen concluded. “I hope that we are going to do investments in paths that make our society more sustainable, livable, and healthy.”

—Javier Barbuzano (@javibarbuzano), Science Writer

El Compostaje Humano es el Camino Ecológico a Seguir

Thu, 04/09/2020 - 12:00

This is an authorized translation of an Eos article. Esta es una traducción al español autorizada de un article de Eos.

El compostaje humano puede ser una opción funeral viable y al mismo tiempo más amigable que otros métodos de tratamiento postmortem, de acuerdo con un estudio piloto reciente.

El 16 de febrero, durante una conferencia de prensa en la reunión anual de la Asociación Americana para el Avance de la Ciencia en Seattle, Wash., la investigadora principal Lynne Carpenter-Boggs mencionó: “Actualmente, en los Estados Unidos existen dos opciones primarias para la disposición o destino final del cuerpo humano, que son la cremación y el entierro”.

Además, dijo: “Estamos usando materiales naturales y frescos de plantas adicionadas al cuerpo humano, lo cual produce una gran cantidad de calor y una rápida descomposición”. El material resultante es “una reserva de carbón que puede durar muchas décadas, y mejora la salud del suelo y el crecimiento de las plantas”.

Una Alternativa Sostenible

En 2019, el 93.8 % de las personas que morían en Estados Unidos eran enterradas o cremadas, según la Asociación General de Directores de Funerarias. Sin embargo, estos dos métodos funerarios tienen un gran impacto ambiental. El entierro vierte en el suelo millones de litros de fluido de embalsamamiento, además de miles de metros cúbicos de madera. El dióxido de carbono liberado a la atmosfera por la cremación es equivalente al liberado por un carro manejado a cientos de kilómetros.

Los métodos para funerales más amigables con el ambiente, como la hidrólisis alcalina y el entierro verde, no están disponibles en todo Estados Unidos.



El compostaje de personas fallecidas, o la reducción orgánica natural, ofrece otra alternativa sostenible a la cremación y al entierro. Este idea comenzó con la práctica de compostar ganado muerto.

“Realmente es una práctica muy común en granjas de ganado” dijo Carpenter-Boggs, científica del suelo en la Universidad Estatal de Washington en Pullman y asesora de investigación para la compañía de compostaje humano Recompose.

“El compostaje es una práctica aceptada y ciertamente, en muchas áreas, una práctica promovida por los departamentos de agricultura y de salud para la disposición del ganado muerto.” La investigadora mencionó que el equipo comenzó compostando materiales de ganado y posteriormente ajustó los procesos para restos humanos.

“Es altamente efectivo, pero ha tomado algo de análisis y reajustes para hacer de este un proceso que sea permitido y aceptable para uso humano”.La investigadora agregó: “Es altamente efectivo, pero ha costado bastante análisis y algunos reajustes para hacer de este un proceso que sea permitido y aceptable para uso humano”.

En el estudio piloto los investigadores compostaron seis sujetos donados, usando para empezar, material de plantas naturales. Después de 4–7 semanas, cada cuerpo pasó de 2–3 yardas cubicas a 1.5–2 yardas cubicas de compostaje y huesos. Carpenter-Boggs dijo que, así como con la cremación, un lugar de compostaje comercial probablemente procesaría aún más el material para tratar los restos esqueléticos.

Según Carpenter-Boggs, el proceso de compostaje calentó el material en descomposición a una temperatura suficiente para esterilizarlo en niveles aceptables establecidos por la Agencia de Protección Ambiental, acabando con los patógenos y bacterias más comunes. Esto permitiría el almacenamiento seguro del compostaje resultante en una urna o directamente incorporado al suelo.

Vía e-mail, la investigadora Carpenter-Boggs dijo a Eos: “hemos logrado pruebas contundentes, y estoy muy satisfecha con el material resultante de nuestro último grupo de sujetos”, también mencionó “para uso comercial, habrá más cambios en la infraestructura y el proceso”.

Una Red Positiva para el Medio Ambiente

El impacto ambiental total del compostaje humano no puede ser completamente evaluado hasta que se convierta en un proceso comercial, dice Carpenter-Boggs, pero no estará completamente libre de emisiones carbono. Aún es necesario construir, calentar y dotar de electricidad plantas de compostaje. Sin embargo, a diferencia de la cremación y el entierro, el compostaje tendrá un impacto positivo en el medio ambiente y la sostenibilidad.

“Existe un gran interés en este método de parte del público y de las compañías funerarias”.Jennifer Debruyn una ecologista microbiano de la Universidad de Tennessee en Knoxville, que no está involucrada con este trabajo, dijo a Science News que el compostaje es “una excelente opción”. Además agregó: “la idea de aplicarlo para humanos, para mí, como ecóloga y como una persona que ha trabajado en compostaje, honestamente tiene mucho sentido”.

El compostaje humano tiene un largo camino por recorrer antes de convertirse en una práctica común. En mayo de 2019, Washington se convirtió en el primer estado de Estados Unidos en legalizar esta práctica. Una legislación similar está siendo considerada en California y Colorado.

“Existe un gran interés en este método de parte del público y de las compañías funerarias”, dijo Carpenter-Boggs. “Tomará tiempo legalizar el proceso en más estados y estandarizarlo para nuevas instituciones”

—Kimberly M. S. Cartier (@AstroKimCartier), escritora de Eos

This translation was made possible by a partnership with Planeteando. Esta traducción fue posible gracias a una asociación con Planeteando. Traducción de Sofía Barragán Montilla @AlleBlack de @Geo_Latinas y Edición de Alejandra Ramírez de los Santos @alerasant.

First Issue of AGU Advances Highlights Influential Science

Thu, 04/09/2020 - 11:59

I am thrilled to announce that the first issue of AGU Advances, AGU’s new flagship journal, is now online.

AGU Advances is a highly selective, gold open-access journal that publishes seminal research across the Earth and space sciences and related interdisciplinary fields. This research includes full-length research articles that advance our science and commentaries that discuss recent scientific results or trends and put them in context for a broader audience. Our editorial team also highlights important research published in Earth and space science and provides additional editorial content.

In AGU Advances, we aim to publish papers with immediate impact within a field.The research papers and associated content included in this first issue provide a great demonstration of the breadth of new research being published in Earth and space science, as well as excellent examples of the kinds of research papers and commentaries this influential journal will publish.

In AGU Advances, we aim to publish papers with immediate impact within a field that answer an important question or provide results that change the way researchers approach the problem in the future. Diamond et al. analyzed long-term satellite observations in a unique region over the ocean to provide a robust quantification of the impact of shipping-produced aerosols on Earth’s atmospheric heat exchange associated with low clouds. Their estimate provides a much-needed measurement of the influence of aerosol particles on cloud reflectivity that can be used to constrain the effect of similar aerosol-cloud effects on the global energy balance.

Papers with convergent impact span multiple fields to present an important result that could not be achieved without collaboration. Palmroth et al. coordinated observations from camera-wielding citizen scientists to discover and explain a new type of subauroral optical emission consisting of regular waves (“the dunes”). This research has additional impact in that the mechanism the authors suggest to explain this phenomenon provides a window into the dynamics of the mesosphere, the layer above the stratosphere, that are difficult to study using standard observation techniques.

AGU Advances also provides timely commentaries that put scientific developments into a broadly understandable perspective.Finally, we are looking for papers that have societal impact. Yin et al. combined new satellite observations to quantify how the large floods that delayed crop planting across the U.S. Midwest in 2019 affected subsequent crop productivity. The new study shows that a model of crop productivity driven by new satellite measurements of plant photosynthesis is in-line with an analysis of the regional decline in carbon dioxide driven by plant growth. This study provides a test for how effective this multisatellite approach is for measuring regional carbon dioxide changes, which is a must for future carbon monitoring systems.

AGU Advances also provides timely commentaries that put scientific developments into a broadly understandable perspective. Our first issue has two good examples. The commentary by Jolivet and Frank seeks to find commonalities across the many methods and tectonic settings where aseismic (slow) slip has been observed to advance understanding of this important energy release mechanism in fault zones. Xie summarizes the critical importance of ocean warming patterns for understanding overall planetary warming and climate sensitivity by highlighting how atmospheric and ocean dynamics interact with observed patterns of ocean warming on both regional and interhemispheric scales.

Along with publication of these important articles, AGU has also supported this research with additional outreach to the press and public. A new electronic digest will accompany each issue of AGU Advances, providing an accessible and digestible way to stay up-to-date on the latest research in the new journal and in other journals chosen by our editors.

We hope you will stay tuned for future issues of this journal and, more importantly, that you will help us make AGU Advances a premier journal for high-impact Earth and space science by submitting your best work to us.

—Susan Trumbore (trumbore@bgc-jena.mpg.de), Editor in Chief, AGU Advances

What’s in a Seminar?

Thu, 04/09/2020 - 11:59

In a hallway in the Department of Geosciences at the University of Massachusetts (UMass) Amherst hang posters advertising all the scientists who have participated as invited speakers in the department’s weekly seminar series over the past few years. These individuals represent an impressive range of geoscience disciplines, and the posters serve to announce that this department values a variety of research specialties. Yet for underrepresented students who have not always felt seen, welcomed, or a sense of belonging in the department or in the field at large, these posters are also a reminder that most of the scientists our seminar series celebrates are senior, white, and male.

We set clear, concrete goals that we considered achievable within 1 year: At least 50% of the roughly 20 speakers would be women, and more than one speaker would be a person of color.When we volunteered to coordinate the Geosciences Lecture Series for the 2017–2018 academic year, we knew we wanted to do something different. We set clear, concrete goals that we considered achievable within 1 year: At least 50% of the roughly 20 speakers would be women (up from an average of 40% over the previous 4 years), and more than one speaker would be a person of color. We solicited nominations from the entire geoscience faculty via email, but of the 40 nominations we received, only eight were women, and few were nonwhite. We knew it would be difficult to meet our goals from that pool, so we followed up with a specific request for more nominations of white women and people of color, which yielded three additional names. Given that we needed to balance representation of different research disciplines and respect scheduling constraints of invited speakers and faculty hosts, this didn’t give us much flexibility to meet our goals.

We brainstormed solutions to diversify the nomination pool. First, we encouraged faculty to nominate a former student or current postdoc of the senior scientist they had nominated. But faculty often preferred their original nominee for a variety of reasons, including that the person was a collaborator or they “didn’t know” the senior scientist’s students or postdocs. Second, we tried providing our own speaker suggestions and asking faculty to nominate them. However, we were then asked to vouch for these individuals’ speaking abilities, or we were told that faculty were uncomfortable inviting someone they didn’t know or that there wasn’t enough funding to bring speakers from far afield.

With these constraints, we did our best to put together a series for the year that met our goals. In the process, we learned that the challenges we faced in diversifying the seminar series were not unique to our own department, nor are they unique to the geosciences. This made us wonder: What would our ideal seminar series look like?

Building a BRiDGE

While coordinating the Geosciences Lecture Series, we learned why seminars matter to the members of our community. For our faculty, seminars provide an opportunity to bring established colleagues and collaborators to campus. For invited speakers, visits spark new ideas for projects and collaborations while also filling out the “invited talks” section of their curricula vitae. Seminars expose postdocs and students, some of whom have had few opportunities to attend conferences, to research topics and methods not represented in their departments and help them identify next steps for their own research or careers.

A poster describing the BRiDGE program hangs in the Department of Geosciences at the University of Massachusetts Amherst beside flyers announcing invited speakers who participated in the department’s weekly seminar series. Credit: Benjamin Keisling

Through our efforts to organize the series, we also identified other potential seminar benefits that we wanted to cultivate. For example, we had valuable conversations with early-career faculty visitors about navigating the academic job market, and we wanted more students to have access to those kinds of discussions. We also considered how creating space to highlight the broader impacts of the speakers’ research and how it intersects or engages with communities that they serve could increase audience engagement.

We decided our ideal seminar series would involve speakers from underrepresented communities and would provide a platform for these scholars to share experiences and perspectives that inform their research, including about the communities their work serves or the professional and personal obstacles they overcame. It would also provide opportunities for underrepresented students to see early-career scholars who may share their identities or experiences in science, technology, engineering, and mathematics (STEM) and who could provide career advice that is tailored toward students from diverse backgrounds. Above all, we realized that every time we invited a seminar speaker into our community—through invited seminar series that are held in departments across the university—we had the opportunity to meet these needs.

Through this coalition with graduate students in other departments who shared our vision, we conceived BRiDGE, a first of its kind, multifaceted seminar series.Beginning in 2018, we built a coalition with graduate students in other departments who shared our vision. Through this coalition, we conceived BRiDGE, a first of its kind, graduate student–led, multifaceted seminar series. After successfully applying for a seed grant through a campus-wide diversity initiative, the School of Earth and Sustainability and the College of Natural Sciences at UMass Amherst recognized the ongoing and potential future impacts of our initiative and provided additional support.

BRiDGE encompasses three types of speaker presentations—called BRiDGE2Science, BRiDGE2Impacts, and BRiDGE2Students—that each support our mission. BRiDGE2Science presentations are traditional science talks that are cosponsored by a hosting academic department and embedded into that department’s regularly scheduled seminar series. BRiDGE2Impacts presentations are events such as talks, workshops, or panels in which the invited speaker, or BRiDGE Scholar, chooses the topic and structure for their discussion and shares how they use science to make an impact in their community. BRiDGE2Impacts events have sparked conversations about racial justice in affordable housing, navigating academia as a single parent, supporting underrepresented undergraduate students in research programs, identifying our hidden privileges, and other topics. BRiDGE2Students events involve a mentoring lunch that connects underrepresented postdocs and graduate students from different disciplines with successful scientists who share some of their identities and experiences. BRiDGE2Impacts and BRiDGE2Students events have been widely attended by members of many different departments and programs.

We are conscious of “cultural taxation,” which is the unique burden placed on faculty from marginalized groups at predominantly white institutions of doing excess (often unrewarded) work to promote diversity and inclusion [Padilla, 1994], so we provide BRiDGE Scholars with additional professional development benefits. In designing these benefits, we considered some of the reasons that early-career and minoritized scientists are not invited to speak in seminar series, including their “speaking ability” being unknown to faculty nominators. In response, we offer visiting scholars the opportunity to have their science talk filmed and put online to provide an example of their speaking ability. In addition, BRiDGE Scholars have the option to be featured on student podcasts, and students write summaries and reflections of each BRiDGE2Impacts presentation for our website, so the extra effort put in by the scholar is celebrated, documented, and searchable.

Through our efforts, BRiDGE has become a recognized brand on campus, and with 14 scholar visits completed and several more planned, we are creating prestige around the title of “BRiDGE Scholar” within our wider community.

Encouraging Broader Change

We have been developing ways to measure the impact of the program at UMass Amherst. The first barrier to this effort was a lack of existing data with which to compare our results—obtained through surveys of BRiDGE Scholars and seminar attendees—because our departments do not collect data about impacts of their seminars. This year, however, a university-approved plan created by BRiDGE committee members to quantify the impacts of BRiDGE Scholar visits is under way. We are also continuing to collect quantitative survey data about the program.

Considering the success of BRiDGE so far, we believe that other departments and programs could undertake similar initiatives to better serve the next generation of geoscientists.The response from students who have attended BRiDGE seminars has been positive. One anonymous respondent wrote, “It was such an empowering and rejuvenating experience to hear the BRiDGE lecturer discuss her personal experience with developing her career as a researcher. It really helped me to put my personal growth as a scientist in perspective…. As a woman in science, I felt like a lot of [the] personal struggles of the lecturer and the students resonated with me, but I think anyone, regardless of background, would benefit a lot from discussions like this.”

Considering the success of BRiDGE so far, we believe that other departments and programs could undertake similar initiatives to increase diversity, equity, and inclusion (DEI) and better serve the next generation of geoscientists. In fact, one past BRiDGE Scholar, Paula Welander, a microbiologist and associate professor of Earth system science at Stanford University, has since started a similar program there. “By inviting early-career, minoritized faculty to give both a departmental seminar and a broader impacts seminar, we are able to highlight the scientific and societal impacts diverse scientists can bring to the table,” Welander said. “And because invited departmental seminars are often viewed as an honor or privilege, we send a very important message to our community about who we value as scientists and experts in our field.”

Here are five ways to improve your program’s seminar series:

Look at who is invited to give seminars and set goals for increasing diversity. These goals should be guided by demographic data about your department and about its invited speakers and by considering how students and early-career scientists in your department could benefit from exposure to scientists who reflect parts of their identity and experience. Broaden the networks you rely on to identify candidate speakers. Professional networks often comprise individuals with similar academic and career trajectories. In the geosciences, most networks of faculty and professional researchers are overwhelmingly white and male. Allowing students to nominate speakers they want to hear from is a way to tap into different networks. Another way to broaden and diversify scientific networks is to form meaningful relationships with affinity organizations, such as the National Association of Black Geoscientists, the Society for Advancement of Chicanos/Hispanics and Native Americans in Science, the National Organization of Gay and Lesbian Scientists and Technical Professionals, the International Association for Geoscience Diversity, and the Earth Science Women’s Network. Invite diverse speakers to your seminar series. In our experience, members of underrepresented groups continue to be overlooked as potential seminar speakers because no one has previously taken the initiative to invite them. Break this cycle by committing your department to inviting seminar speakers who claim one or more marginalized identities. Such opportunities are especially important for underrepresented students to get career advice, recommendations, and feedback from people who have faced personal and professional obstacles relevant to their own experiences.Provide dedicated spaces and times for students to engage in conversations with visiting scholars. Such opportunities are especially important for underrepresented students, who are unlikely to see their identities or experiences reflected in the faculty of their own department, to get career advice, recommendations, and feedback from people who have faced personal and professional obstacles relevant to their own experiences. Furthermore, early-career scholars often bring different institutional and experiential perspectives that can help students navigate challenges they face at their home institutions. Encourage seminar speakers to spend 5–10 minutes during their presentation to discuss how their science affects communities they serve. In a time when many scientists are increasingly seen as untrustworthy by large segments of the U.S. population, it is important for scientists to explain how their work benefits society. Such discussions also help people understand the underlying purposes of a scientist’s research and help to engage people from different disciplines during seminar talks.

Many institutions today are declaring commitments to improving DEI. Yet despite their good intentions, acting on those commitments remains challenging. We believe we were successful in developing BRiDGE because we acted on our values and focused on making small changes with big impacts. We challenge all members of the geoscience community to be proactive, intentional, and creative when thinking about the roles they can play in supporting and advancing DEI goals. Instead of waiting for solutions to come from someone else, why not take a chance at building something tailored to your program’s needs?

Atmospheric Scientists Show Resilience in the Face of Lockdowns

Wed, 04/08/2020 - 16:45

Geoscience During COVID-19 Geohealth: Science’s First Responders   Atmospheric Scientists Show Resilience in the Face of Lockdowns   Coronavirus Lockdown Brings Clean Air to Spanish Cities   During a Pandemic, Is Oceangoing Research Safe?

For the past few weeks, Jen Morse and a colleague have had to ski 6 kilometers to a snow-buried shack on Niwot Ridge to collect data.

Once at this remote, windswept spot on the Front Range of the southern Rocky Mountains of Colorado, Morse, a climate technician at the University of Colorado Boulder, fills four heavy flasks of mountain air, which she carries down in her backpack. Skiing the full distance isn’t the norm, “but it’s hard to social distance in the cab of a snowcat,” Morse said.

Hundreds of such carefully collected flasks get shipped to the National Oceanic and Atmospheric Administration’s (NOAA) Global Monitoring Laboratory in Boulder each week from such remote locations as Hawaii, Mongolia, and Antarctica. In Boulder, scientists analyze the flasks’ contents to determine how the levels of trace and greenhouse gases, such as carbon dioxide and methane, are fluctuating or increasing.

“There are some very specific things that we can learn right now that are going to turn out to be valuable in the long run.”But over the past few weeks, many countries have implemented strict measures to curb the spread of the coronavirus disease (COVID-19), placing cities and even entire countries on lockdown, and NOAA researchers have scrambled to keep the flask collection going. “We’ve never had a situation where we’ve had the potential to lose the flask data from so many sites at the same time,” said Arlyn Andrews, who manages NOAA’s Global Greenhouse Gas Reference Network.

So far, more than 90% of the flask sites are still sampling, and automated measurements made at in situ sites continue to provide data for carbon dioxide and methane. Doing whatever is safely possible during the pandemic to sustain monitoring is important, not least for maintaining records, scientists assert. “There are some very specific things that we can learn right now that are going to turn out to be valuable in the long run,” said Prof. Joost de Gouw at the University of Colorado Boulder.

Going Local

When news of the impending lockdown reached de Gouw on 11 March, he knew he had to act fast. With his group, he physically moved a mass spectrometer to a prime site on the university campus where it could measure the changing levels of organic gas compounds in the background ambient air. “It was hectic, but we got it done in time,” de Gouw said. “And now our instrument is happily chugging away.”

The instrument measures organic compounds, in the form of gases, that emanate from transportation, agriculture, vegetation, oil and gas production, and personal care products such as cleaning materials. De Gouw hopes that the measurements will help researchers discriminate how much air pollution comes from individual sources.

“In normal times, all of these compounds are emitted where people live and where they drive, so they come from similar locations at the same times, and it is difficult to decide what the relative contributions are,” de Gouw said. “Now we are taking one important source away—cars—so then what do we see?”

Already, de Gouw’s data have revealed several improved air quality days in the Boulder region.  “There is a wow factor of the level of pollution that all of us combined put into the atmosphere, and that is now no longer present,” de Gouw said.

A Big-Picture Perspective 

While de Gouw’s mass spectrometer is revealing changes in local air quality, the Dutch/European Space Agency (ESA) Tropospheric Monitoring Instrument (TROPOMI), which is on the ESA’s Copernicus Sentinel-5P satellite, has enabled researchers to observe the changes in air pollution at a global level. .

Sentinel-5 TROPOMI satellite images show a sharp reduction in nitrogen dioxide concentrations over China in February 2020. Credit: NASA

“It is something that we have never seen before, such a big change in air pollution levels in such a short time frame.”Observations from TROPOMI have shown that on average, across China, levels of nitrogen dioxide have dropped by 35% from the day that lockdown measures went into effect, compared with the same time period in 2019.  The TROPOMI data also reveal reduced concentrations of nitrogen dioxide in the major cities of Europe, such as Milan, Paris, and Madrid, in the past couple of weeks.

“It is something that we have never seen before, such a big change in air pollution levels in such a short time frame,” said Pieternel Levelt from the Royal Netherlands Meteorological Institute and Delft University of Technology in the Netherlands.

To fully understand the impacts of the lockdowns on nitrogen dioxide concentrations, scientists are starting to investigate a combination of satellite, meteorological, and ground data. “We are testing our knowledge in the extremes,” Levelt said.

Challenging Times

Unlike the scenario with nitrogen dioxide, it will take some time before scientists begin to see changes in the rate of greenhouse gas emissions, Andrews said. Their network, which includes in situ monitoring and flask samples taken on planes in addition to the ground-based flask data, was designed to look at changes on continental to global scales, and large reductions in emissions will register only a small signal at remote sites, such as the long-running Mauna Loa Observatory in Hawaii.

“But if we have a slowdown that lasts for 5 or 6 months, the signal will start to stand out even at these remote sites,” Andrews said.

Regional signals over the United States and Europe will likely be larger, but it’s too early to see anything yet, Andrews said. “Signals of the economic slowdown will be larger than what we see at remote sites, but the economic impacts are only just starting.”

Factors such as photosynthesis and respiration play a larger role in emissions at the continental sites, meaning that it can be even more difficult to find a clear signal of reduced emissions in the data, Andrews said.

The scientific questions that the lockdowns present are interesting but are secondary to concerns about global health and the economic impacts of coronavirus and the safety of colleagues locally and around the world. The logistics of trying to manage the network via telework while also homeschooling children are challenging, Andrews said.

Levelt concurs. Despite the scientific possibilities, it’s still a difficult situation for scientists, Levelt said. “Everyone has someone in their family that they are worried about, and that is also true for us scientists,” Levelt said. “That is our main concern—we are just human beings like everyone else.”

—Jane Palmer (@JanePalmerComms), Science Writer

Tracking Trace Elements Across the Arctic Ocean

Wed, 04/08/2020 - 14:05

The Arctic Ocean is uniquely influenced by biogeochemical processes on continental shelves, which underlie more than half the ocean’s area. Shelf-derived nutrients and carbon are rapidly transported across the central ocean basin—from the East Siberian and Laptev Seas toward the Fram Strait between Greenland and Svalbard—by a surface current known as the Transpolar Drift (TPD) on timescales of 1–3 years.

The TPD carries clues to how climate change is reshaping the Arctic, the fastest warming region on Earth. During the peak of summertime melt in 2018, the discharge rate of the largest Arctic rivers was 20% higher than in the 1980s. As temperatures rise, increasing discharge from rivers and melting permafrost could have an impact on primary production across the basin. But there is a dearth of data on the transport of trace elements and carbon in the remote region, where icebreakers are a critical component of any sampling expedition.

Charette et al. took advantage of data collected by the GEOTRACES program during a pan-Arctic survey in 2015. The research cruises crossed the TPD twice, measuring concentrations of nutrients, trace elements, and carbon concentrations along the way. In the new study, the researchers used radionuclide tracers and ice flow models to infer the mass transport rate for the TPD and to estimate trace element fluxes from the shelves to the central Arctic Ocean, with the goal of better understanding how climate change will affect Arctic basin ecosystems.

Isotopic ratios of radium—which is not biologically important itself but acts as a tracer for other elements—indicated that continental shelf sediments were the dominant source of the element in the TPD. Concentrations of some dissolved trace elements—notably, iron, cobalt, nickel, copper, mercury, neodymium, and thorium—were higher than expected within the TPD. Concentrations of aluminum, vanadium, gallium, and lead, meanwhile, were lower. The observed trace metal enrichments resulted in large part from the elements binding to dissolved organic matter sourced from Arctic rivers and permafrost thaw.

As both temperatures and freshwater inputs to the Arctic Ocean increase in the future, researchers expect Arctic waters to become increasingly stratified, which will affect nutrient availability and could mean that the TPD will become even more important in primary productivity in the Arctic Ocean and beyond. Understanding the elemental “fingerprint” of the TPD could help researchers track flows and uptake of nutrients and elements into other ocean basins, and in the increasingly ice-free Arctic. (Journal of Geophysical Research: Oceans, https://doi.org/10.1029/2019JC015920, 2020)

—Kate Wheeling, Freelance Writer

A Subglacial Lake in Antarctica Churns Out Nutrients

Wed, 04/08/2020 - 12:36

Hot water may be a foreign concept on the West Antarctic Ice Sheet, but it’s highly useful: In 2013, researchers used tens of thousands of liters of the stuff to bore deep into the ice, reaching a hitherto hidden world—a subglacial lake. They sampled the lake’s waters, a scientific first, and now they’ve analyzed its biogeochemistry. The team found that subglacial Lake Whillans contains roughly 5,400% of the organic carbon needed by microbes at the lake’s drainage outlet. This lake may therefore provide an important source of nutrients for the Southern Ocean’s vast food chain, the researchers suggest.

Bringing Europa to Earth

Subglacial lakes lurk in the darkness below glaciers, capped by hundreds or even thousands of meters of ice. Created by melting triggered by the pressure of the thick ice sheet above, roughly 400 such lakes are scattered across Antarctica, researchers believe. Subglacial lakes represent more than just an extreme environment, however—they’re also a tantalizing analog for ice-covered oceans elsewhere in the solar system, such as the one on Jupiter’s moon Europa.

“Whillans is really the first lake that has been directly sampled.”In late January 2013, a team of researchers working with the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project bored through the ice of West Antarctica using a hot-water drilling system. They melted a hole roughly 60 centimeters in diameter and nearly 800 meters deep to reach Lake Whillans. This body of water is about the size of Oregon’s Crater Lake but only as deep as a backyard swimming pool.

The WISSARD team collected water and sediment from the lake using sterile vessels. Cleanliness was paramount during the fieldwork because contaminating the lake would bias analyses of its biogeochemistry. “It’s not a simple operation,” said Jemma Wadham, a glaciologist at the University of Bristol in the United Kingdom who was not involved in the research. “You have to put in place a whole series of environmental protection protocols. Everything that goes down that hole has to be clean and sterile.”

Other subglacial lakes have been breached before, like Antarctica’s Lake Vostok, but water and sediment samples have never been retrieved, said WISSARD team member Trista Vick-Majors, a microbial ecologist at Michigan Technological University in Houghton. “Whillans is really the first lake that has been directly sampled.”

Powering a Food Chain

Subglacial Lake Whillans is part of an interconnected network of lakes that drains into the ocean at the grounding zone of the Ross Sea Shelf. It’s the last stop for water on its way off the Antarctic continent, said Vick-Majors, so its waters directly reflect what’s entering the Southern Ocean. The Antarctic food chain—crowned by megafauna such as penguins, whales, and seals—is anchored by phytoplankton, bacteria, and zooplankton, which are sustained by waterborne nutrients that lakes like Whillans could provide.

When the WISSARD team analyzed water pulled up from Lake Whillans, they surprisingly found that it was rich in microbial life, researchers reported in 2016. “We expected a very dilute, low-activity environment,” said Vick-Majors. “That’s not what we found.”

Have Time, Make Molecules

“It’s like a little biological reactor.”Now Vick-Majors and her colleagues have analyzed the biogeochemical effects of those microbes on Lake Whillans’s water. By studying the fluorescent properties of organic matter in the water, the researchers determined that carbon-containing molecules—sources of food and energy—are largely microbially produced. Thanks to microbes, Lake Whillans is acting like a nutrient concentrator, said Vick-Majors. “When the water slows down in these lakes, it sits there for long enough that microbes can chew on it,” she said. “It’s like a little biological reactor.”

Vick-Majors and her collaborators next calculated, on the basis of the rate at which Lake Whillans empties, how much water and therefore carbon flowed into the Ross Sea each year. They compared those data with laboratory experiment–based estimates of the carbon needs of bacteria living at the grounding zone of the Ross Ice Shelf. Vick-Majors and her colleagues found that carbon levels in Lake Whillans were 5,400% higher. “The calculated carbon coming from subglacial outflow far exceeds the demand,” said Vick-Majors. Subglacial Lake Whillans could therefore be an important contributor of nutrients to the region, the researchers concluded.

“That’s a fascinating discovery and matches nicely with what we see elsewhere on glaciers and ice sheets,” said the University of Bristol’s Wadham. It also makes sense, Wadham said, because the undersides of ice shelves are dark and microbes there can’t produce their own carbon via photosynthesis. “They need a subsidy.”

These results were published in Global Biogeochemical Cycles in February.

—Katherine Kornei (@KatherineKornei), Science Writer

Capturing Pluto’s Heartbeat in a Computer

Wed, 04/08/2020 - 11:30

Pluto has a 1 pascal nitrogen atmosphere, so its pressure is 1/100,000 of the pressure of the Earth’s atmosphere, or less than a percent of that of Mars’ atmosphere. This world was visited by the New Horizons mission in a fly-by in 2015, and recently, very sophisticated climate model simulations were performed to study its atmosphere.

Despite its thinness, Pluto’s atmosphere hosts very active circulations driven by the very faint solar input at the distance of, on average, 40 times the Sun-Earth distance. These circulations are also strongly affected by the surface properties of the dwarf planet. Near the equator, the Sputnik Planitia basin hosts a large nitrogen ice cap that forms a part of the heart-shaped bright feature in visible images from the New Horizons mission.

According to Bertrand et al. [2020], a recent global climate modeling study benefiting from data from New Horizons, this ice cap drives an oscillating circulation in Pluto’s atmosphere, reminiscent of a heartbeat synchronized to Pluto’s day. The winds are driven by the flow caused by the night-day variations of condensation and sublimation (direct phase transition from ice to vapor) of this nitrogen ice cap, and the spiraling directions of these winds are controlled by the local topography. The same condensation-sublimation flow also drives an atmospheric retro-rotation higher up, where the atmosphere turns in the opposite direction compared to the solid body.

In addition to the general circulation of the atmosphere, the model was used to investigate the possible atmospheric mechanisms at play in creating some of the intriguing features on Pluto’s surface revealed by imaging from the New Horizons mission.

Citation: Bertrand, T., Forget, F., White, O., Schmitt, B., Stern, S. A., Weaver, H., et al. [2020]. Pluto’s beating heart regulates the atmospheric circulation: Results from high‐resolution and multiyear numerical climate simulations. Journal of Geophysical Research: Planets, 125, e2019JE006120. https://doi.org/10.1029/2019JE006120

—Anni Määttänen, Editor, JGR: Planets

How Modern Emissions Compare to Ancient, Extinction-Level Events

Tue, 04/07/2020 - 17:46

A single pulse of activity during the end-Triassic eruptions released as much carbon dioxide as humans are expected to emit over the course of the 21st century. Many of Earth’s most severe extinction crises have coincided with some of its largest volcanic events. At the end of the Triassic era (some 202 million years ago) the supercontinent Pangaea was breaking apart, the Atlantic Ocean was opening up, and millions of cubic kilometers of magma were bursting through Earth’s crust in a region known as the Central Atlantic Magmatic Province (CAMP). Pulses of volcanic activity, each lasting a few hundred to a few thousand years, released huge quantities of greenhouse gases from Earth’s internal plumbing system. The spike in carbon dioxide and other volcanic gases contributed to global warming and ocean acidification that wiped out more than three quarters of species on Earth.

In a new study, an international team of researchers sought to quantify the amount of carbon dioxide released during the event. Their results, published today in Nature Communications, show that a single pulse of activity during the end-Triassic eruptions released as much carbon dioxide as humans are expected to emit over the course of the 21st century.

Researchers have known for some time that the formation of large igneous provinces is often followed by dramatic shifts in climate or mass extinctions. The Deccan Traps in India likely contributed to the demise of the dinosaurs, for example, and the Siberian Traps are believed to have triggered the end-Permian extinction, in which more than 90% of life on Earth was wiped out.

“The CAMP is one of the most impressive large igneous provinces on Earth,” said Richard Ernst, a professor at both Canada’s Carleton University and Russia’s Tomsk State University who was not involved in the study. The total volume of the eruptive event would bury all of the United States, including Alaska, beneath a kilometer of basaltic magma, according to Ernst.

“These events are increasingly recognized to cause massive environmental change, and that’s being well documented by the precise dating that’s demonstrated that they’re associated in timing with the mass extinctions and other climatic change,” Ernst said. “The issue then turns more and more to what’s the mechanism?”

As a potent greenhouse gas, carbon dioxide is understood to drive these climate changes, he said. But what’s less clear is just how much carbon dioxide was released and where exactly it comes from: Is it largely derived from the mantle itself, or is it formed when hot magma hits the crust, cooking the organic materials found in sedimentary rocks? The answer has implications aboveground as well as belowground.

To find out, the team behind the new study looked at samples of basaltic lavas collected from the United States, Canada, Morocco, and Portugal, now distant landmasses that were separated by the emergence of the large igneous province known as CAMP.

But estimating carbon dioxide emissions for ancient eruptions is a challenge, according to Manfredo Capriolo, a Ph.D. student at the University of Padova in Italy and lead author on the new study. “Carbon is a volatile element,” he said. “It readily degasses during magma rise and eruption. Moreover, carbon may be added to old rocks due to alteration.”

The team had to distinguish between magmatic carbon in their samples and carbon that had been taken up as part of the natural weathering process of basalt deposits. To do so, they looked for melt inclusions in their samples—the blobs of melted rock and gases trapped within the crystals that form as magma cools.

“The crucial new data were those we obtained by Raman microspectroscopy analysis, which allowed us to detect micrometric carbon-bearing bubbles within melt inclusions, below the rock surface,” Capriolo said.

The team used carbon dioxide concentration in the bubbles to estimate the total abundance of carbon dioxide in the magma before it reached the surface to be 500 to 1,000 parts per million.

The high concentration of carbon dioxide in the magma helps to explain the pulsing eruption style that characterized the CAMP, according to the study authors. Carbon dioxide can accelerate the rise of magma through Earth’s layers. (Hawaii’s fountain-like eruptions, for example, are driven by its carbon dioxide–rich basalts.)

On the basis of the total volume of the CAMP, the carbon dioxide concentration of the magma, and the ratio of glass to gas bubbles within the melt inclusions, the team estimated the total amount of volcanic carbon dioxide released into the atmosphere.

“If we’re talking about going up 2° to 3° over a hundred years, we’re 20% of the way to a mass extinction.”They found that a single pulse of activity—the eruption of 100,000 cubic kilometers of magma over some 500 years—could have had a significant impact on the Triassic climate, much as our current emissions are drastically reshaping our world today. The entire CAMP event would have released roughly 100,000 gigatons of carbon dioxide—enough to warm the world by 10°C to 15°C. Put another way, Ernst said, “if we’re talking about going up 2° to 3° over a hundred years, we’re 20% of the way to a mass extinction.”

“There are countless variables that should be taken into account to foresee future climate change scenarios and that we are not able to constrain for the end-Triassic world,” Capriolo cautions. “However, as geoscientists, we warn that the currently ongoing carbon dioxide emissions are similar to those that led to the end-Triassic mass extinction.”

For Ernst, the new study underscores the importance of understanding Earth’s deep past in predicting how it will respond to future climate change. Climate scientists typically use sophisticated climate models based on decades of historical weather and climate data to predict future climate change. But, he said, “there’s a wealth of data from looking at Earth’s geology, Earth’s four and half billion year history of dramatic climate change, to provide insight into modern climate change.”

—Kate Wheeling (@katewheeling), Science Writer

Machine Learning Improves Weather and Climate Models

Tue, 04/07/2020 - 12:49

Both weather and climate models have improved drastically in recent years, as advances in one field have tended to benefit the other. But there is still significant uncertainty in model outputs that are not quantified accurately. That’s because the processes that drive climate and weather are chaotic, complex, and interconnected in ways that researchers have yet to describe in the complex equations that power numerical models.

Historically, researchers have used approximations called parameterizations to model the relationships underlying small-scale atmospheric processes and their interactions with large-scale atmospheric processes. Stochastic parameterizations have become increasingly common for representing the uncertainty in subgrid-scale processes, and they are capable of producing fairly accurate weather forecasts and climate projections. But it’s still a mathematically challenging method. Now researchers are turning to machine learning to provide more efficiency to mathematical models.

Here Gagne et al. evaluate the use of a class of machine learning networks known as generative adversarial networks (GANs) with a toy model of the extratropical atmosphere—a model first presented by Edward Lorenz in 1996 and thus known as the L96 system that has been frequently used as a test bed for stochastic parameterization schemes. The researchers trained 20 GANs, with varied noise magnitudes, and identified a set that outperformed a hand-tuned parameterization in L96. The authors found that the success of the GANs in providing accurate weather forecasts was predictive of their performance in climate simulations: The GANs that provided the most accurate weather forecasts also performed best for climate simulations, but they did not perform as well in offline evaluations.

The study provides one of the first practically relevant evaluations for machine learning for uncertain parameterizations. The authors conclude that GANs are a promising approach for the parameterization of small-scale but uncertain processes in weather and climate models. (Journal of Advances in Modeling Earth Systems (JAMES), https://doi.org/10.1029/2019MS001896, 2020)

—Kate Wheeling, Science Writer

Organic Matter in Arctic River Shows Permafrost Thaw

Tue, 04/07/2020 - 12:48

The Arctic is the fastest-warming region on Earth, and increasing temperatures are thawing permafrost, releasing more carbon into the atmosphere, and accelerating warming. These feedbacks concern scientists because roughly 850 gigatons of carbon—representing 25%–50% of all soil organic carbon on Earth—are believed to be stored in the permafrost at present.

Arctic rivers receive carbon both from the seasonally thawing top layer of the soil and from eroding riverbanks. Besides the ongoing permafrost thaw, warming of the region also affects the rivers by extending the ice-free season and by changing the way water flows through the landscape and interacts with carbon in the soil.

In a new study, Bröder et al. analyze water from two sites in the Kolyma River watershed in northern Siberia. The Kolyma River flows northward across the easternmost part of Russia, eventually draining into the East Siberian Sea; its watershed is the largest on Earth that is entirely underlain by continuous permafrost. For half of the year, the river is covered by ice; its flow peaks after snowmelt in early summer. The researchers collected water from two separate locations near the town of Cherskiy, Russia. One batch came from the main stem of the Kolyma River, and the other was taken from a small headwater stream known as Y3. Samples were collected every 4–7 days during the ice-free periods of 2013 and 2015.

The team analyzed both water sources for suspended particulate organic carbon (POC) and dissolved organic carbon (DOC); they also conducted isotope analyses to help understand where the carbon was coming from. The carbon in both sample sites followed a typical pattern, with the highest concentrations showing up in the first few weeks after the ice breakup and tapering off later in the summer. Overall, the main stem of the Kolyma contained more POC, as well as older carbon, than the Y3 headwater stream. Conversely, the Y3 stream had higher DOC than the Kolyma.

The researchers say these findings indicate that POC in the main Kolyma comes from both recent vegetation and permafrost, whereas the POC in the Y3 stream comes primarily from younger plants. The researchers attribute the increased POC concentration in the main Kolyma to active riverbank erosion, which would be less of a factor in the smaller stream. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2019JG005511, 2020)

—David Shultz, Science Writer

The Arctic Ocean May Not Be a Reliable Carbon Sink

Tue, 04/07/2020 - 12:47

Historically, scientists have believed that the Arctic Ocean will be an important carbon sink in the coming years—ice melt will increase the surface area that’s exposed to the air, facilitating carbon uptake from the atmosphere, and cold Arctic waters can store more carbon dioxide (CO2) than warmer waters.

Or at least that’s what was supposed to happen. But scientists have begun to suspect that this might not be the case, and new research suggests that the Arctic Ocean is, in fact, not as reliable a carbon sink as we thought. Using data from three research cruises (in 1994, 2005, and 2015), scientists were able to chart how the physical properties of the Arctic Ocean (including total alkalinity, temperature, and dissolved inorganic carbon) changed over time.Over the course of the past 20 years, the amount of dissolved inorganic carbon in Arctic waters has unexpectedly decreased.

They found that over the course of the past 20 years, although the amount of CO2 in the atmosphere has gone up, the amount of dissolved inorganic carbon in Arctic waters has unexpectedly decreased.

That’s because reduced sea ice isn’t the only major change that’s happening in the Arctic Ocean.

“There’s actually been a huge increase of fresh water into the Arctic Ocean,” said Ryan Woosley, a marine physical chemist at the Massachusetts Institute of Technology and lead author of the study. “The Arctic is kind of unique compared to the other oceans because there’s a huge amount of river input compared to the size of the ocean…and fresh water has a very low alkalinity or buffering capacity, so this has reduced the ability of the Arctic Ocean to take up CO2.”

“There are so many physical and biogeochemical processes that are linked together that determine the [CO2] uptake.”But Manfredi Manizza, a biogeochemical oceanographer at the Scripps Institution of Oceanography, said that although there has, indeed, been an increased input of fresh water to the Arctic Ocean, the reasons for the less-than-expected uptake of anthropogenic carbon may be slightly more complicated than the explanation presented in the paper. He said that different rivers carry different amounts of total alkalinity and dissolved inorganic carbon into the Arctic Ocean, so understanding these inputs is an important part of determining the ability of the Arctic to take up atmospheric CO2. Furthermore, there are many other changes taking place in the Arctic at the same time, each of which could also affect the ability of the ocean to take up CO2.

“There could be other pieces of the story that we don’t know about yet,” he said. “There are so many physical and biogeochemical processes that are linked together that determine the [CO2] uptake in the end.”

Manizza pointed out that temperature is increasing rapidly in the Arctic Ocean—much faster than it’s increasing in the other oceans. And changing temperatures are associated with a whole suite of other changes: Sea ice is melting, removing a protective barrier between the ocean and the wind, which could affect ocean stratification. Warmer temperatures and changes in ocean stratification could affect the amount and the types of primary producers that can live in the Arctic. All of these factors, either directly or indirectly, may affect the amount of CO2 that the Arctic Ocean can absorb from the atmosphere.

Arctic Freshening

However, Manizza agreed that Arctic freshening is occurring, which could have major implications for Arctic Ocean ecosystems.

“The fresh water and this lowering alkalinity are causing a rapid decrease in pH,” said Woosley. This means that like many other oceans, the Arctic is becoming more acidic.

Although the effects of Arctic Ocean acidification are not fully understood, Manizza said that acidification could alter the types of plankton that are able to survive there, which could in turn affect animals higher up the food chain. There are even concerns that acidification could threaten economically important Arctic fisheries.

Furthermore, Woosley said the Arctic not being an effective carbon sink could have important global implications: “More [CO2] will stay in the atmosphere, increasing global warming.”

Ultimately, both Woosley and Manizza agree that more data are needed. Woosley is hoping that another research cruise will take place in 2025, which would help to expand our knowledge of a region historically difficult to study. He hopes that having more data will shed light on the dynamics of Arctic Ocean freshening and acidification, which could affect Arctic ecosystems and fisheries, and Arctic Ocean CO2 uptake, which could affect the climate of our entire planet.

—Hannah Thomasy (@HannahThomasy), Freelance Science Writer

Kumamoto and Thom Receive 2019 Mineral and Rock Physics Graduate Research Award

Tue, 04/07/2020 - 12:46
Citation for Kathryn M. Kumamoto Kathryn M. Kumamoto

Kathryn Kumamoto will receive the 2019 Mineral and Rock Physics (MRP) Graduate Research Award for her outstanding doctoral work investigating plasticity and the role of water in the dynamics of upper mantle rocks.

Katie’s work on the plasticity of olivine used instrumented nanoindentation to resolve over 40 years of debate on the plastic strength of the lithosphere. She determined that the strength of olivine depends on a characteristic length scale (e.g., grain size). Katie recognized that this size effect explains the previous inconsistency among laboratory investigations while also demonstrating that most previous studies overestimate the strength of the lithosphere.

Katie also challenged two long-standing hypotheses regarding the role of water in upper mantle deformation. As an initial step, she characterized a set of new standards for secondary ion mass spectrometry that are now available for public use and represent a valuable resource for the community. Using these new standards, Katie unpicked the role of water in localizing deformation in upper mantle shear zones in the Josephine peridotite. Previous work asserted that water is central to the process of localization, but Katie demonstrated that although water does appear important, localization in these shear zones critically depends on a complex interplay between transport of a silicate melt and local equilibration between the melt and solid phases. She also challenged previous interpretations regarding the link between water content and the development of crystallographic preferred orientations (CPOs). Katie demonstrated that CPO type can be modified without significant changes in water content. She alternatively proposed that CPO type can be modified by changes in deformation kinematics, which she validated through numerical simulation.

Since completion of her Ph.D. at Stanford University, Katie has become a National Science Foundation Division of Earth Sciences postdoctoral fellow hosted at the University of Oxford and now uses synchrotron-based deformation-DIA experiments to further elucidate the physics of plastic deformation in upper mantle rocks.

—Lars Hansen, University of Minnesota, Minneapolis

 

Response

I am honored and humbled to receive the MRP Graduate Research Award. I am fortunate to have worked with many outstanding individuals who have supported me in my scientific career. My Ph.D. advisor, Jessica Warren (University of Delaware), was an incredible role model and mentor throughout my graduate school experience and strongly encouraged me to examine my research questions from multiple perspectives, ranging from fieldwork to detailed geochemical analyses to experimental rock deformation. Lars Hansen (University of Minnesota) has been an invaluable colleague since my first year in graduate school, and we have collaborated on a wealth of activities that have spanned from small group presentations all the way to multiuniversity collaborative proposals and experimental work at large synchrotron facilities. During graduate school, I also had the distinct honor to work closely with Erik Hauri (Carnegie Institution of Washington) to develop and document standards and protocols for measuring water in mantle minerals with secondary ion mass spectrometry.

It is also important to acknowledge those scientists in my undergraduate career who helped me to develop a deep and passionate interest in pursuing research in the field of geology. Bud Wobus (Williams College), Mea Cook (Williams College), and Bjorn Mysen (Carnegie Institution of Washington) all played substantial roles in providing me with research opportunities, guidance, and encouragement, along with a healthy dose of good humor when anticipated research results were less than forthcoming. My hope is that I also can provide similar inspiration and support to others who wish to understand the inner workings of our planet.

Thank you to AGU and the Mineral and Rock Physics section for this award and for supporting graduate research.

—Kathryn M. Kumamoto, University of Oxford, Oxford, U.K.

 

Citation for Christopher A. Thom Christopher A. Thom

For his Ph.D. thesis, Christopher Thom conducted groundbreaking research at the intersection of geophysics and materials science. Through application of methods not usually associated with rock mechanics, such as atomic force microscopy (AFM) and nanoindentation, Chris made fundamental contributions to our understanding of the roughness of natural faults and the frictional and rheological behavior of rocks. He extended measurements of fault roughness to the nanoscale using AFM, demonstrating self-affine roughness over at least 11 orders of magnitude in length scale. He showed that self-affinity at small scales results from the “smaller is stronger” dependence of yield strength on the size of the deforming volume, which he measured on actual fault surfaces via nanoindentation. Chris was also a major contributor to a paper that placed new constraints on the strength of the Earth’s lithosphere by considering the size dependence of the yield strength of olivine. Chris also provided fundamental constraints on the physical mechanisms of rock friction by measuring the nanoindentation creep rate of quartz in near-zero versus comparatively high humidity environments. Previous friction experiments on quartz rocks and powders for the same range of humidity showed that the time dependence of friction disappears at low humidity but is conspicuous at higher humidity. Chris’s experiments revealed no difference in the nanoindentation creep rate of quartz at low and high humidity, demonstrating that the time dependence of the frictional strength of quartz rocks cannot be due solely to asperity creep, the standard view of the past 40 years. Finally, Chris demonstrated how nanoindentation can be used to determine the bulk rheological behavior of rocks by conducting days-long nanoindentation creep experiments on halite single crystals; the resulting data agree remarkably well with those for polycrystalline halite deformed in macroscopic experiments.

Chris Thom has already had a remarkable impact on the field of mineral and rock physics for a scientist at this early stage of their career. On behalf of the AGU Mineral and Rock Physics section, I am very pleased to present the 2019 Mineral and Rock Physics Graduate Research Award to Christopher Thom.

—David L. Goldsby, University of Pennsylvania, Philadelphia

 

Response

I am greatly honored and humbled to receive the 2019 Graduate Research Award from the Mineral and Rock Physics section of AGU, and I am grateful for the wonderful people I worked with during my time at the University of Pennsylvania.

I would first and foremost like to thank my Ph.D. adviser, David Goldsby, for giving me an opportunity to succeed and for providing constant encouragement along the way. He allowed me to pursue a wide range of research topics with unique methods such as nanoindentation. His guidance and years of experience tackling difficult issues related to rock friction paved the way for my work on the physical origins of frictional aging and scale-dependent plasticity.

I would also like to thank several individuals who have influenced my approach to science during my Ph.D. Rob Carpick introduced me to the world of tribology, which has affected how I approach rock friction problems at small scales. Emily Brodsky introduced me to measurements of fault roughness and always encouraged me to think about how my work related to the bigger picture. George Pharr was instrumental in teaching me nanoindentation methods and providing in-depth technical support whenever I needed it. A number of other collaborators such as Lars Hansen and Katie Kumamoto provided stimulating discussions on many topics related to plasticity, which I will continue to work on in my future career.

—Christopher A. Thom, University of Oxford, Oxford, U.K.

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