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Dust from Colliding Asteroids Masqueraded as a Planet

Mon, 04/20/2020 - 19:25

Planets don’t normally triple in size, but that’s what Fomalhaut b seemingly did.

Originally heralded as an extrasolar planet, this object probably isn’t a planet after all, researchers have now suggested. By analyzing unpublished Hubble Space Telescope data, scientists have shown that it’s more likely an expanding cloud of dust created by a catastrophic collision between large asteroids. Given that such impacts should be exceedingly rare—occurring only once every few hundred thousand years, the team calculated—this discovery was downright lucky.

An Oddball

“Fomalhaut b has always been enigmatic.”In 2008, astronomers announced the discovery of Fomalhaut b orbiting a star roughly 25 light-years away. It joined a rarefied club: The object was one of a handful of exoplanets that had been directly imaged (as opposed to being detected using the transit method or the radial velocity method, for instance). But Fomalhaut b had some distinctly unplanetlike characteristics—it didn’t emit thermal radiation, for starters, and it was growing significantly in size. “Fomalhaut b has always been enigmatic,” said András Gáspár, an astronomer at Steward Observatory at the University of Arizona.

To better pin down the nature of Fomalhaut b, Gáspár and George Rieke, an astronomer also at Steward Observatory, mined archival data from the Hubble Space Telescope. They collected observations of Fomalhaut b obtained from 2004 to 2014, including unpublished data from 2013 and 2014.

Expanding and Going Sideways

Gáspár and Rieke found that Fomalhaut b resembled a point source—as expected for a distant planet—in observations from 2004 and 2006. But in the next data set, collected in 2010, Fomalhaut b had ballooned in size and now looked like a cloud. Between 2004 and 2014, Fomalhaut b expanded by roughly 7,500,000 kilometers, or about 5% of the Earth–Sun distance, per year, the researchers calculated. “That’s pretty quick,” said Gáspár.

Fomalhaut b’s position in the sky was also odd, the scientists found. Rather than swinging around its host star in a planetlike elliptical orbit, “its trajectory is leading radially away from the central star,” said Gáspár.

Dust to the Rescue

These decidedly unplanetlike characteristics led Gáspár and Rieke back to an idea proposed earlier by other researchers—Fomalhaut b is not a planet but, instead, an expanding cloud of dust. This seemingly unorthodox hypothesis is consistent with Fomalhaut b’s bizarre properties: A dust cloud would reflect lots of optical light from its host star but wouldn’t produce much of its own thermal radiation; an expanding cloud would explain Fomalhaut b’s threefold increase in size, and a dust cloud would appear to move radially away from a star because the smallest and lightest dust particles are literally blown outward by starlight.

The dust probably derived from a collision of asteroids, astronomers have proposed. And the Fomalhaut system doesn’t lack for asteroids—it’s known to host a dusty debris disk, an amalgam of dust and small rocky bodies akin to our own solar system’s asteroid belt and Kuiper Belt.

Gáspár and Rieke modeled asteroid impacts and their resulting dust clouds. They calculated that two asteroids roughly 200 kilometers in diameter smashing together could have produced Fomalhaut b. On the basis of the estimated density of asteroids near Fomalhaut’s debris disk, such an event would statistically occur every few hundred thousand years, the team estimated. These results were published today in the Proceedings of the National Academy of Sciences of the United States of America.

Too Rare?

“A collision between objects is a fairly natural explanation.”“A collision between objects is a fairly natural explanation,” said Grant Kennedy, an astronomer at the University of Warwick in the United Kingdom not involved in the research. “It’s pretty hard to create a puff of dust…in any other way.”

But the likelihood of such a collision might be far lower than what Gáspár and Rieke estimate, Kennedy cautions. “Previous calculations have suggested that the frequency of collisions between objects that are about 100 kilometers in size is very, very low, fewer than one in the age of the system.” Because the Fomalhaut system is about 400 million years old, it’s exceedingly unlikely that we’d be witness to such an event, said Kennedy. “People will no doubt revisit this analysis, just like they did for the original Fomalhaut b discovery.”

—Katherine Kornei (@KatherineKornei), Science Writer

Shaping Water Management with Planetary Boundaries

Mon, 04/20/2020 - 11:56

In 2009, scientists introduced the planetary boundaries framework, which identified nine critical Earth system processes—chemical pollution, climate change, and freshwater consumption among them—and established a stress limit, or boundary, for each. If a boundary is eclipsed, the Earth system could be irreversibly destabilized. For example, the current boundary for freshwater use is the point at which human water consumption disrupts environmental flow and impedes the global hydrological cycle; recent work has suggested potential additional subboundaries for groundwater, atmospheric water, soil moisture, and frozen water.

Planetary boundaries provide a conceptual scaffolding for understanding how humanity affects Earth’s systems—defining, in effect, humanity’s safe operating space within the environment. The challenge, however, lies in translating global limits into actionable local management. In a new study, Zipper et al. propose an integrated method for understanding and managing water resources across spatial scales.

The authors provide a local-global linkage by combining two water management approaches: the fair shares approach and the local safe operating space approach. The fair shares approach is a top-down strategy that sets a planetary boundary value and allocates water impacts locally. Those allocations could be doled out to political entities like nations or cities, or they could be assigned to individual companies or industrial sectors. In contrast, the local safe operating space approach works from the bottom up to identify the limits beyond which local water resources are disrupted. Under this system, each region could determine a limit on water cycle modification based on local socioenvironmental needs.

By combining the top-down and bottom-up approaches to water management, the authors suggest that their framework takes advantages of strengths of both while limiting each strategy’s drawbacks. By using both methods, the management framework is relevant for the global Earth system as well as for local communities. Furthermore, the strategy can be used to govern within both social (cities, nations, companies, and industries) and physical (watersheds, aquifers, continents) contexts.

In addition to laying out the proposed methodology, the new study includes a case study for its application focused on a Colombian watershed degraded by decades of human activity. Although it has not been field-tested, the researchers say the strategy serves as a useful guide to managing water that considers both local and global constraints. (Earth’s Future, https://doi.org/10.1029/EF001307, 2020)

—Aaron Sidder, Freelance Writer

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

A Tribe’s Uphill Battle Against Climate Change

Mon, 04/20/2020 - 11:54

For several years, Fawn Sharp has seen her tribe on the coastline of Washington state lurch from crisis to crisis: Rising sea levels have flooded the Quinault Indian Nation’s main village, and its staple sockeye salmon in nearby rivers have all but disappeared—a direct hit to the tribe’s finances and culture.

Now Sharp, the 49-year-old president of the Quinault, plans to move the tribe to higher ground, restore the fishery, and diversify its economy. The projects are foundering, she says, because of a lack of federal money to help Native Americans adapt to climate change.

The Quinault’s struggles reflect the broader challenges of Native Americans, who are among the most vulnerable to the impacts of climate change because their tribes are tied to reservation land and rely on natural resources for subsistence and trade, according to the National Climate Assessment report written by federal agencies.

Tribes are ill-equipped to adapt their reservations to increasing threats from storms, flooding, drought and wildfires because their communities are typically poor and because federal programs offer scant support.Southwestern tribes such as the Navajo Nation face acute water shortages as the Colorado River dries up. Northern tribes including the Bar River Band of Lake Superior Chippewa are losing access to wild rice and walleye due to warming in Lake Superior, which has heated faster than any other U.S. body of water.

Tribes are ill-equipped to adapt their reservations to increasing threats from storms, flooding, drought and wildfires because their communities are typically poor and because federal programs offer scant support. The Interior Department’s Bureau of Indian Affairs provides $10 million a year for tribal climate resilience planning nationwide, and FEMA provides another $20 million to tribes under a fund to protect communities from natural disasters.

That’s not much when spread among more than 500 tribes, said Sharp, who has made climate change the top issue in her newly acquired additional role as president of the National Congress of American Indians, which represents 535 registered tribes.

In addition to lobbying for more federal support, Sharp has set her sights on industries that contribute to climate damage. To finance a relocation of some tribe members, she plans to propose a carbon tax for companies doing business on the reservation, which features rich timberlands and a port. The measure would make it the first tribe in the United States to price carbon.

The salmon is an icon of Quinault culture, ubiquitous in art and imagery around the reservation. Credit: Alan Davey, CC BY-NC-ND 2.0

She’s also considering a lawsuit against big oil companies she believes should help pay the tab for climate-damage mitigation.

“Those who are directly responsible for causing the damage should be paying,” she said, for “generations of exploitation.”

The Western States Petroleum Association industry group declined to comment on potential lawsuits, saying only that oil companies and tribes should be “working with each other and not against each other.”

Vanishing Salmon

On a February morning at the Quinault Indian Nation’s fish processing plant in Taholah, manager Shane Underwood grew frustrated by yet another small catch. A lone fisherman had arrived with five steelhead salmon after hours on the river.

“We used to process 40,000 to 50,000 pounds of fish a day. Now we’re lucky to see 1,000,” Underwood said as she hosed down the catch.

The salmon is an icon of Quinault culture, heavily featured on totem poles and in artwork on tribal buildings, and a traditional meal at family gatherings and in tribal rituals. Now it’s also a symbol of climate damage.After the steelhead season comes the sockeye blueback run, a salmon fishery unique to the Quinault reservation that has all but disappeared. For a third straight April, the Quinault have closed the river to blueback fishing after its fisheries department forecast a fifth consecutive record-low run.

The salmon is an icon of Quinault culture, heavily featured on totem poles and in artwork on tribal buildings, and a traditional meal at family gatherings and in tribal rituals. Now it’s also a symbol of climate damage.

The summer runoff from Anderson glacier in the Olympic mountains northeast of the reservation once cooled the Quinault river system. The last of the glacier melted nine years ago, warming the river and distressing the salmon, said Justine James, a cultural historian who specializes in timber, fish and wildlife for the Quinault Environmental Protection Department.

The Quinault’s Business Committee created a Salmon Habitat Restoration Program, buffering streams, repairing culverts and roads near the river, and clearing fish runs. The tribe is also embarking on a $1.2 million project to restore the floodplain on the Upper Quinault River in hopes of creating better spawning habitats.

“We have been eating the salmon for thousands of years,” James said. “It’s our spirit, our heart.”

Before the collapse, the tribal run seafood enterprise Quinault Pride, along with fisheries management, sustained about 350 direct and indirect jobs and generated about $29 million in revenue, according to a 2015 report by economic consulting firm Resource Dimensions, making it the second largest source of revenue for the Quinault after its resort and casino.

For fisherman Kokomo “Koke” Snell and others, the decline in the salmon fishery has upended a cherished career and a family tradition. Unable to fish blueback, Snell will pay the bills working a temporary job in village beautification—clearing the riverbanks of debris and sprucing up the homes of tribal elders.

“It doesn’t feel right,” Snell said.

Higher Ground

The Quinault are racing to defend themselves against another threat—flooding of its main village.

Wedged between the sea and steep hills forested with Douglas firs, Taholah’s lower village lies in the Cascadia Subduction Zone, putting it at risk of inundation from a major earthquake and tsunami. It’s stone sea wall is already damaged from high tides, winds and storm surge—all exacerbated by climate change—exposing residents to repeated flooding.

In 2017, the Quinault signed off to move nearly 700 residents and key buildings most at risk—including the school, senior center, food market and gas station—to higher ground.In 2017, the Quinault signed off to move nearly 700 residents and key buildings most at risk—including the school, senior center, food market and gas station—to higher ground. The whole relocation project will cost up to $150 million.

Some construction has already begun in the new village, using $15 million worth of tribal funds. But finishing the entire relocation project is more than the tribe can afford and complicated by the fact some non-tribal members own land in the area designated for the relocation, officials say.

“It is vital that we repatriate this land base so we can control these decisions,” said Sharp.

One of the best options that the tribe had to pay for the project was a Washington state bill that would have funded climate-related projects with a $15 per ton fee on industrial carbon emissions. But that measure was defeated in 2018 amid a multi-million dollar campaign led by the oil industry.

“That was probably the lowest point I had hit in all my years of this climate struggle,” said Sharp, a former lawyer who lobbied hard for the bill. “But it was a battle in a  bigger war. Losing this land is simply not an option.”

—Valerie Volcovici (@ValerieVolco), Reuters

This story originally appeared in Reuters. It is republished here as part of Eos’s partnership with Covering Climate Now, a global journalism collaboration committed to strengthening coverage of the climate story.

Mountain Streams Exhale More Than Their Share of CO2

Mon, 04/20/2020 - 11:42

Sample a stream that runs through the Amazon, the Congo basin, or Canada’s Northern Cordillera, and you’re likely to measure a large amount of carbon dioxide (CO2) dissolved in the water. That carbon mostly comes from plants, animals, and microbes that decompose in the water or return their carbon to the surrounding soil.

“Mountain streams may represent 10%–30% of the total flux from streams and rivers. They represent just 5% of the surface area of streams and rivers.”Mountain streams, however, start their journeys at high altitudes, which lack the carbon-rich soil of their lowland cousins. They haven’t been widely studied, and the few measurements that exist suggest that their water is carbon poor. Because of that, it’s been assumed that mountain streams don’t contribute all that much to the combined CO2 emission from river networks.

However, new research recently published in Nature Communications suggests that altogether, mountain streams likely emit more than half as much CO2 as the oceans absorb annually and emit more CO2 per square meter than tropical and boreal streams.

“Mountain streams may represent 10%–30% of the total flux from streams and rivers. They represent just 5% of the surface area of streams and rivers,” said lead researcher Åsa Horgby, a hydrogeologist at École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. In terms of global carbon flux, “they are overrepresented, but it’s really hard to estimate how much because we just don’t have enough data.”

Turbulence Releases Carbon Dioxide

Coauthor Tom Battin, who heads the Stream Biofilm and Ecosystem Research Laboratory at EPFL, said that their seeming unimportance to the carbon cycle and geographic inaccessibility have made mountain streams “aqua incognita” for carbon emission studies.

Recent research found that turbulent streams, like those flowing down mountainsides, exchange gas with the air more quickly than placid streams do, something that hadn’t been accounted for in global models of rivers’ CO2 flux.

“If you have a Coca Cola bottle and you shake it, for example, you get a higher flux. And this is what’s happening in mountain streams.”“If you have a higher concentration [of CO2] in water than in the atmosphere, you have an outgoing flux. And then the opposite” for an ingoing flux, Horgby explained. “If you shake the water more, like if you have a Coca Cola bottle and you shake it, for example, you get a higher flux. And this is what’s happening in mountain streams.”

Prompted by that discovery, Horgby’s team wanted to reevaluate mountain streams’ contributions to the global carbon cycle. The researchers gathered CO2 concentration and elevation measurements for mountain streams around the world to calculate the amount of CO2 exchanged with the atmosphere.

“Our CO2 model is building on 323 measurements, which is not a lot on a global scale,” Horgby said, but in situ carbon data simply don’t exist for most mountain streams. Too, mountain streams across the globe are very different from each other, so it wouldn’t be accurate to use an average carbon flux measurement to represent unmeasured streams.

Churning water releases carbon dioxide up to 10 times more quickly than placid water. This is Furka Pass in Switzerland’s Canton of Valais. Credit: Tambako The Jaguar, CC BY-ND 2.0

Instead, the researchers used the available data to develop new models that relate CO2’s rate of air exchange with more readily measured stream properties like temperature, width, and flow speed. Measurements from 12 high-altitude monitoring stations in the Swiss Alps validated those formulas, which the team then used to calculate the CO2 flux one by one for more than 23,000 mountain streams in Switzerland and nearly 2 million across the globe.

“Rather than aggregating CO2 and gas exchange for some area,” said Robert Hall, a stream and river ecologist at the University of Montana in Polson, “the authors predicted a CO2 concentration and a gas exchange rate for each stream, multiplied these, and then summed them up by region. This approach should provide higher accuracy and allow estimation of uncertainty.” Hall was not involved with this research.

An Ocean’s Worth of Carbon

The researchers found that on average, a Swiss mountain stream will emit 3.5 kilograms of carbon per year for every square meter of stream area. That flux per area is unexpectedly high, the team said. Even though mountain streams account for roughly 5% of the global area covered by rivers and streams, their combined CO2 outflux—about 1.7 gigatons of carbon per year—is about the same as that of tropical streams and “substantially higher” than that of boreal streams and rivers, which cover much more area.

Most of the world’s mountain streams likely have a net annual outflux of carbon dioxide per area (light blue to red), but a few areas like the Tibetan Plateau are a net carbon dioxide sink (dark blue). The units in this map are kilograms of carbon per meter squared per year. Credit: Horgby et al., 2019, Figure 3d, https://doi.org/10.1038/s41467-019-12905-z, CC-BY 4.0

“When you take all of the inland waters—streams, rivers, lakes, etc.—we think that they emit as much CO2 per year as the oceans globally absorb per year,” Battin said. “The fluxes, although in different directions, are the same order of magnitude. For the ocean, it’s something like 2.5 gigatons of carbon per year. For the inland waters it’s between 2–3 gigatons.”

“Even in high-elevation ecosystems where terrestrial productivity may be low, there is a large transfer of carbon to aquatic systems.”Most of that emission has been assumed to come from rivers running through carbon-rich areas. This new estimate “implies that even in high-elevation ecosystems where terrestrial productivity may be low, there is a large transfer of carbon to aquatic systems,”  said David Butman. Butman studies the biogeochemistry of watersheds at the University of Washington in Seattle and was not involved with this research.

The team found that by area, most mountain streams were net sources of CO2. Just over 10%, however, were unexpected carbon sinks, including streams running through the interior of the Tibetan Plateau and the Altiplano region in the Andes. This study wasn’t designed to find out why that might be, Horgby said, but will hopefully spark future research.

This study “presents a snapshot in time and space,” Butman said. “This is our best guess at an annual contribution. However, we know that streamflow is driven by daily changes in precipitation, melting,” and other factors. What’s more, our understanding of gas exchange with turbulent water is still developing, Hall and Butman each pointed out, so these estimates of carbon flux may evolve along with our understanding of the underlying physical process. Battin said that data collection from the Swiss stations is ongoing and will help pin down the carbon flux more accurately.

Where Does the Carbon Come From?

“High-mountain streams are typically above the tree line,” Battin said, “so there’s not much organic carbon up there. Their catchments are devoid of vegetation, and their soils are poorly developed.”

So where does the carbon come from? The researchers suggested that the carbon might come primarily from the surrounding rocks and soil rather than from carbon dissolved directly into the stream water.

“These authors convincingly showed that the CO2 from Swiss streams was some combination of soil respiration and weathering,” Hall said. “Thus, the CO2 was produced outside the stream and emitted to the atmosphere by the stream.”

“Many of us claim,” Battin said, “that streams and rivers and lakes emit lots of CO2 into the atmosphere and therefore they are major players in the global carbon cycle. Now we understand more and more that especially for the high-mountain streams, most of that CO2 is from the catchment, not from the stream itself.”

—Kimberly M. S. Cartier (@AstroKimCartier), Staff Writer

A New Global Map of Seafloor Fluid Expulsion Anomalies

Mon, 04/20/2020 - 11:30

Fluid migration in marine sediments is a widespread but still poorly understood process. The presence of focus fluid emissions is relevant because of the related gas emission and carbon budget estimate, for local ecosystem and for potential risk, as fluid emission may trigger slope instabilities. Despite their relevance, an estimate of fluid emission at a global scale is still lacking.

Phrampus et al. [2020] present the first database of focused fluid flow sites (e.g., cold seeps) and associated SEAfloor FLuid Expulsion Anomalies (SEAFLEASs) at a global scale. The paper presents a compilation of data and observations about their distribution.

In general, SEAFLEASs shows a random distribution along the continental margin but this observation is heavily biased toward the North America continental margin. Using a machine learning technique, the authors produced a probability model for the distribution of SEAFLEASs and this model has been validated using a random and geospatial validation technique.

This new global database, along with its prediction, covers a gap in knowledge while adopting a modern technique, and it will certainly be of interest to a wide audience of marine geologists, geophysicists and biologist.

Citation: Phrampus, B. J., Lee, T. R., & Wood, W. T. [2020]. A global probabilistic prediction of cold seeps and associated SEAfloor FLuid Expulsion Anomalies (SEAFLEAs). Geochemistry, Geophysics, Geosystems, 21, e2019GC008747. https://doi.org/10.1029/2019GC008747

—Claudio Faccenna, Editor in Chief, Geochemistry, Geophysics, Geosystems

A Graceful Way to Study Daily Water Storage on Land

Fri, 04/17/2020 - 11:40

Earth’s fresh water is often on the move, for example, as snow and rain fall, glaciers grow or melt, and reservoirs fill or drain, with important implications for humans and climate. Quantifying water stores and understanding where and when natural disasters like droughts and extreme floods—which are becoming more likely as the global climate changes—will strike are priorities for governments and resource managers. On a global scale, one of the best ways to track the movement of terrestrial water is to measure subtle variations in the planet’s gravity. Water represents a significant source of mass on Earth, and as it moves around the planet, satellites can detect the resulting perturbations in gravity over time.

The premier instrument for collecting these kinds of gravity measurements comprises a pair of satellites known as the Gravity Recovery and Climate Experiment (GRACE). Data from the GRACE mission and its successor, GRACE Follow-On, have provided a detailed account of terrestrial water movement on the planet’s surface. However, the data these satellites collect have limited resolution both temporally (monthly) and spatially (300–500 kilometers). These coarse resolutions make drought and flood forecasting more challenging. Recently, scientists have tried to combine GRACE data with climate models to estimate water movement on shorter timescales, achieving only mixed success.

In a new study, Croteau et al. describe a new method for analyzing GRACE data to estimate terrestrial water movement on daily timescales. The technique works backward from the monthly water mass concentration data provided by GRACE. The researchers find that by decreasing the spatial resolution—zooming out to consider large swaths of land of between 400,000 and 800,000 square kilometers—they can recover daily signals of terrestrial water movement. They are also able to quantify the relationships and trade-offs between measuring larger spaces and shorter time intervals ranging from 1 day to 2 weeks.

The researchers conclude that the method should allow future work to apply GRACE data to studies of submonthly signals, offering substantial benefits for researchers and resource managers alike. (Journal of Geophysical Research: Solid Earth, https://doi.org/10.1029/2019JB018468, 2020)

—David Shultz, Science Writer

This Week: Fake News, Floods, and a Dazzling Flyby

Fri, 04/17/2020 - 11:38

Nonscientists Struggle to Separate Climate Fact from Fiction. I appreciated this clear and fascinating look into how people who aren’t scientists understand climate change. The people in the study found it very difficult to separate fact from fiction in climate science, yet they had an inflated sense that they could. As Kim Cartier points out, this might have something to do with the barrage of misinformation about climate change out there, such as the majority of YouTube climate videos promoting nonconsensus views. As we’ve been struggling to find science-based facts during the coronavirus outbreak, I think these lessons are not only topical but also crucial for our scientific literacy and communication practices. —Jenessa Duncombe, Staff Writer

 

Cities Are Flouting Flood Rules. The Cost: $1 Billion. This eye-opening piece airs a frustrating truth: Local jurisdictions across the United States, coastal and inland alike, are not enforcing FEMA’s rule that “[i]f you want publicly subsidized flood insurance, you can’t build a home that’s likely to flood.” And, in turn, the agency itself is not holding these jurisdictions accountable. Surely there are cases when exceptions to the rule are warranted, but when there are hundreds of thousands of policies violating the rule and taxpayers are on the hook for flood claims for these properties, there’s a serious problem that needs to be addressed. —Timothy Oleson, Science Editor

 

BepiColombo Flyby.

Credit: ESA/BepiColombo/MTM, CC BY-SA 3.0 IGO

The European–Japanese spacecraft BepiColombo made its one and only flyby of Earth over the weekend on its way to Mercury. With so much happening on the ground, it’s nice sometimes to sit back and remember that from the eyes of distant passersby, we’re all together in this. —Kimberly Cartier, Staff Writer

 

5 Jobs on My Way to Being a Scientist.

5 jobs on my way to being a scientist and 5 tags:1. Owner/operator Copper River bowpicker (salmon fisherman)2. Fisheries/marine mammal observer3. Hardware store clerk4. Taxi driver5. Long distance truck driver@AndreSobolewski @biochemnick @Hlkimmel @WordChem @PeteEpanchin

— Kendra Zamzow (@earthchemistry) April 7, 2020

My Twitter pal Kendra Zamzow (a truck driver-turned-scientist who lives in a yurt in Alaska and did an American Association for the Advancement of Science congressional fellowship here in D.C. a few years ago) has hooked me on a Twitter thread that is just way too fascinating: List five jobs you’ve had on the way to becoming a scientist, and then tag five people. —Nancy McGuire, Contract Editor

 

In a Pandemic, Should the Experts or the Politicians Be in Charge? The authors succinctly weigh the rights and responsibilities of elected leaders and health care experts, and compare the balance to that of civilian and military decision-making during times of military conflict. There are no easy answers here, but it’s refreshing to acknowledge that managing a pandemic requires a wide swath of expertise: Listen to the scientists, yes…but also listen to experts in conflict resolution, equity and social justice, and on-the-ground workers. —Caryl-Sue, Managing Editor

Tuning in to a Glacial Symphony

Fri, 04/17/2020 - 11:33

The iconic image of a tidewater glacier is likely familiar, even if you’ve never seen one in person: a frozen river of icy white punctuated by blue streaks, brown-gray sediment flecks, dark, shadowy crevasses, and jagged fingerlike fronds of calving icebergs at the snout.

Glaciologist Evgeny Podolskiy thinks this perspective is lacking something important. By metaphorically closing his eyes and opening his ears, Podolskiy’s recent work has revealed that we’re missing something mysterious, dramatic, poetic, and scientifically significant: glacial sounds.

Podolskiy set out to quantify those sounds with a simple but ingenious computer: an iPhone.Podolskiy, a scientist at the Arctic Research Center at Hokkaido University in Sapporo, Japan, has been studying glaciers in Greenland, the Himalayas, and Antarctica, collaborating with large teams using sophisticated instruments to collect data on the dynamics of our cryosphere—Earth’s icy realms. As part of Podolskiy’s and other research, arrays of different seismic waves—mostly outside of the human auditory range—are currently monitored at glaciers.

While working in July 2019 at Bowdoin Glacier in northwest Greenland, walking on ice to maintain his instruments while collecting terabytes of measurement data, Podolskiy realized that if he closed his eyes, he was in a universe of audible sounds. So he set out to quantify those sounds with a simple but ingenious computer: an iPhone. “We have it in our pockets,” marveled Podolskiy, “so instead of just Tweeting…we can actually collect information about environmental processes and study them, producing meaningful and insightful studies.”

That’s exactly what Podolskiy did, publishing the results of his iPhone-sampled tidewater glacier soundscape in Geophysical Research Letters.

Deciphering a Glacier’s Acoustic Fingerprints

Podolskiy identified three main sound sources. First, draining meltwater within a crevasse created pulsating, fluid, oscillating sounds “just like in a bathtub.” Second were bubbles bursting in a pond atop the glacier. Finally, he noted the pounding sounds inside a moulin, the often circular, well-like shafts on an ice sheet. Podolskiy described moulin noise as “a very scary sound because it’s like a waterfall falling from a big height.” Every place he sampled on the glacier had its own acoustic fingerprint.

In surveying available information on ice and water sounds, Podolskiy says he found out more from plumbers than the scientific literature.Podolskiy is not the first to acknowledge how little Western science knows about glacial sounds. In a 1933 paper on bubble- and water-related sounds, astronomer Marcel Minnaert wrote that “physicists have hardly ever investigated the sounds of running water…[and] we know very little about the murmur of the brook, the roar of the cataract, or the humming of the sea.” Polar explorers like Fridtjof Nansen also noted the sounds of glacial surfaces in 1897.

In surveying available information on ice and water sounds, Podolskiy says he found out more from plumbers than the scientific literature. “Plumbers can come to your bathroom, or to my kitchen, listen, and say by ear what is the problem and where it is.”

Podolskiy suggests that understanding the sounds of snow and ice can contribute to hazard assessment and safety. Mountaineers and backcountry skiers, for example, pay close attention to “whoomphing” sounds in the snowpack as signs of instabilities and an imminent avalanche.

“Anything Which Contributes to This Knowledge and Understanding Is Welcomed”

Erin Pettit, an associate professor of glaciology at Oregon State University in Corvallis who was not involved in the study, said, “I think what Evgeny has done is valuable and creative.” His method may have limitations for broader use, “but having some of these examples described is, at a minimum, helpful for expanding our capabilities from more broadly applicable methods,” she said.

The method he uses does have limitations, she noted. Sound traveling through air is very sensitive to properties like wind, which is why infrasound (below 20 hertz) is commonly used in glaciology. At higher frequencies, explained Pettit, you must be very close to the source to be able to interpret the physical processes. “This is great—but that limits this method’s use,” she said.

Nevertheless, Pettit suggests it will be valuable to take what Podolskiy did and use it to expand our understanding of seismic or underwater acoustics that are not affected by the atmosphere.

Leanne Hughes, a geologist with the British Geological Survey in Keyworth, Nottingham, United Kingdom, also not involved in the study, said that understanding meltwater flows is important because the interaction between ice, meltwater, and the glacier bed is crucial in modeling glacial dynamics. “Anything which contributes to this knowledge and understanding is welcomed,” she said. Although acknowledging that some geometric assumptions in the paper need validation by modeling, she called it “an interesting study and one which has a potential to be useful on an outreach and public engagement front too.”

By further opening our ears, as well as our eyes, to glacial processes, Podolskiy suggests that passive acoustic monitoring—eavesdropping on the shouts and whispers of glaciers—may significantly advance our understanding of the cryosphere.

—Lesley Evans Ogden (@ljevanso), Science Writer

New Recognition for Major Players in the Ocean’s Silicon Cycle

Thu, 04/16/2020 - 12:12

The primary contributors to the global silicon cycle are single-celled algae called diatoms, which use silicon dissolved in seawater to build elaborate, rigid shells called frustules of silicon dioxide, or silica. In a new study, Llopis Monferrer et al. show that another group of planktonic organisms, known as Rhizaria, may produce up to 19% of the total amount of biogenic silica in the ocean.

Rhizaria are a diverse group of single-celled organisms that, like diatoms, use dissolved silicon to construct silica frustules. These shells can serve a variety of functions, such as protecting cell structure and providing armor against predators.

Although diatoms are photosynthetic and reside in upper water layers, most Rhizaria are heterotrophic (they rely on external sources for food) and live throughout the open ocean. A growing amount of evidence suggested that Rhizaria may play an unrecognized role in biogenic silica production, but until now, estimates of their contribution remained highly speculative.

To generate the first estimates of the contribution of Rhizaria to the world’s biogenic silica production, the researchers collected plankton samples at 22 sites in the Mediterranean Sea. Focusing on two major groups of Rhizaria—polycystines and phaeodarians—the team conducted experiments using radioactively labeled silicon to measure the organisms’ silica production rates.

Then the scientists combined the results of their experiments with previously published data on the abundance of polycystines and phaeodarians throughout the world’s oceans. The analysis revealed that the shell-building activities of Rhizaria could account for 1%–19% of the total amount of oceanic silicon incorporated into biogenic silica every year.

These findings challenge the view that diatoms have total control over oceanic silicon cycling, a process that is coupled with other biogeochemical cycles, such as the carbon and nitrogen cycles.  (Global Biogeochemical Cycles, https://doi.org/10.1029/2019GB006286, 2020)

—Sarah Stanley, Science Writer

Record-Setting Winds on a Nearby Brown Dwarf

Thu, 04/16/2020 - 12:11

The high-speed winds of hurricanes and tornadoes frequently wreak havoc on Earth. But now scientists have used infrared and radio observations to deduce that much, much faster flows—over 600 meters per second, well off the Saffir-Simpson scale—encircle a brown dwarf roughly 35 light-years away. These results offer a rare glimpse of the atmospheric properties of a distant world and pave the way for measuring the wind speeds of exoplanets, the team suggests.

Winds Here and Elsewhere

Latitudinally flowing “zonal winds” are found throughout the solar system; examples include our own planet’s trade winds and Jupiter’s iconic multihued cloud bands. However, getting a handle on the speeds of these winds on worlds other than Earth takes a bit of sleuthing.

Two sets of measurements are necessary, said Katelyn Allers, an astronomer at Bucknell University in Lewisburg, Pa. One set must trace the rotational period of the world, and the other must trace the rotational period of its atmosphere. By comparing these periods and knowing the size of the planet or brown dwarf, a velocity difference—the speed of the wind on that world—can be calculated, said Allers.

A “Failed Star” in the Lion

Allers and her colleagues did just that for 2MASS J1047+21, a brown dwarf roughly 35 light-years away in the constellation Leo the Lion. Brown dwarfs are “failed stars”: objects with masses between those of gas giant planets like Jupiter and full-blown stars like the Sun. (The mass of 2MASS J1047+21 isn’t precisely known, but it’s probably between 16 and 68 times that of Jupiter, researchers believe.)

“It’s some sort of long-lived phenomenon.”Allers and her collaborators used the Karl G. Jansky Very Large Array in New Mexico to observe 2MASS J1047+21 at radio wavelengths. These observations, which trace the brown dwarf’s magnetic field, reveal the world’s rotational period. The researchers calculated a period of 1.751–1.765 hours, where the uncertainty comes from using different techniques to measure the brown dwarf’s period, said Allers.

The scientists also collected data at midinfrared wavelengths with the Spitzer Space Telescope. These observations trace atmospheric features like clouds and hot spots on 2MASS J1047+21, but it’s impossible to know for sure what structures are present, said Allers. “We can’t really easily distinguish between those different possibilities.”

The researchers tracked low-level but periodic changes in the brown dwarf’s brightness over two separate observing sessions in 2017 and 2018 totaling 21 hours. Interestingly, they recorded consistent sinusoidal variability for both observing epochs, which means that “whatever feature is causing this variability, it lasted for at least a year,” said Allers. “It’s some sort of long-lived phenomenon.” Using their infrared data, Allers and her colleagues calculated a period of 1.734–1.748 hours for 2MASS J1047+21’s atmosphere.

A Minute Faster

On the basis of their measurements, the scientists concluded that 2MASS J1047+21’s atmosphere makes a complete revolution about 0.017 hour, or 61 seconds, faster than the brown dwarf’s interior makes a complete revolution. Armed with knowledge of 2MASS J1047+21’s radius—about 67,000 kilometers, barely smaller than Jupiter—they calculated the brown dwarf’s wind speed: about 650 meters per second.

“It’s certainly higher than what we get for Jupiter.”That’s far, far faster than the strongest hurricanes and tornadoes on Earth (a 70-meter-per-second wind qualifies as a category 5 storm), and it even exceeds the fastest winds recorded in the solar system, said Allers. “It’s certainly higher than what we get for Jupiter.” These results were published in April in Science.

“This is a very nice study,” said Dániel Apai, a planetary scientist at the University of Arizona not involved in the research. “It provides a new method to assess wind speeds on brown dwarfs.”

In the future, Allers and her colleagues hope to extend their analysis of brown dwarf wind speeds to other wavelengths. Data at various wavelengths are valuable because they probe different depths of a world’s atmosphere, said Allers. “That allows you to look at atmospheric dynamics as a function of depth.”

Looking to Planets

Another goal is to use the same technique to measure wind speeds on planetary mass bodies. “The method that we’ve used here can, in principle, be applied to exoplanets,” said Allers. But that’ll require precise radio- and infrared-derived rotational periods for relatively small, faint worlds, the research team concedes. That’s on the edge of what’s possible with current technology, but upcoming telescope facilities like the James Webb Space Telescope, the Owens Valley Long Wavelength Array, and the Square Kilometre Array will “knock that out of the park,” said Allers.

—Katherine Kornei (@KatherineKornei), Science Writer

El Cambio Climático Está Intensificando las Corrientes Oceánicas del Ártico

Thu, 04/16/2020 - 12:02

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

No es secreto que están ocurriendo grandes cambios en el Océano Ártico. Al aumentar la temperatura, alrededor de 2 millones de kilómetros cuadrados de hielo marino se han perdido.

Un estudio reciente liderado por investigadores del Jet Propulsion Laboratory de la NASA en Pasadena, California, ha vislumbrado nuevos efectos de la pérdida del hielo en el giro de Beaufort.

Desde la década de los noventa, el Giro Beaufort ha acumulado alrededor de 8 mil kilómetros cúbicos de agua dulce, que sería suficiente como para cubrir California con hasta 18 metros de agua”.En las últimas décadas, la región del giro de Beaufort ha rotado en sentido de las manecillas del reloj por el viento. Cuando el hielo cubre la superficie del océano, es más difícil para el viento empujar el agua del océano. Pero a medida que esta barrera protectora se derrite (y el hielo remanente se vuelve cada vez más delgado y móvil), el viento es capaz de infringir más energía sobre la rotación del giro de Beaufort.

Thomas Armitage, especialista en percepción remota de la zona polar en el Jet Propulsion Laboratory de la NASA y autor principal del estudio, dijo: “el sistema de corrientes del giro de Beaufort, que se mueven en sentido de las manecillas del reloj, tiende a acaparar y retener el agua dulce en la superficie, haciendo del giro de Beaufort un gran reservorio de agua dulce…Desde la década de los noventa, el giro de Beaufort ha acumulado alrededor de 8 mil kilómetros cúbicos de agua dulce, que sería suficiente como para cubrir California con hasta 18 metros de agua”.

Los torbellinos y la energía disipativa

En el hemisferio norte, cuando las corrientes oceánicas giran en el sentido de las manecillas del reloj, arrastran aguas superficiales hacia el centro de la corriente. Una vez que el nivel superficial de agua dulce—proveniente del hielo derretido, del curso del río y la precipitación—alcanza la mitad del giro, se ve forzado a descender. A medida que más agua dulce se mueve hacia el centro del giro, la interfaz  entre la superficie de agua dulce y el agua salada profunda (llamada haloclina), debería obtener mayor profundidad.

Pero algo extraño está ocurriendo en el giro de Beaufort. Aunque el agua dulce está siendo llevada hacia el fondo, la haloclina no está descendiendo. Por lo tanto, otros procesos deben estar ocurriendo para ayudar a disipar el agua dulce, balanceando así la dotación de agua dulce que llega.

Gracias a la pérdida de hielo marino, los vientos han añadido energía extra al giro de Beaufort. Una manera en la que esta energía extra puede ser disipada es por medio de un mecanismo llamado ice- ocean governor o el regulador entre hielo-océano. Esto significa que el hielo y el mar que está de bajo, se mueven a distintas velocidades produciendo cierta resistencia que ayuda a disipar la energía extra que agrega el viento.

El océano Ártico tiene suficiente agua caliente al fondo como para derretir muchas veces la cobertu-ra de hielo, pero esta está aislada de la superficie por las frías aguas superficiales (que tienden a flo-tar).Pero los investigadores calculan que desde 2007, la energía disipada por el regulador entre hielo-océano ya no ha podido balancear la energía extra que añade el viento.

¿Entonces qué está pasando?

La respuesta es la actividad de unos torbellinos conocidos como “eddies”. Los científicos se dieron cuenta que ha habido un aumento en la actividad de los torbellinos, lo que podría aportar a las discrepancias tanto de la dotación extra de agua dulce, así como la disipación de la energía del giro.

Armitage dijo que este aumento en la actividad de los eddies tiene fuertes implicaciones para las condiciones en el Océano Ártico: “Mayor actividad de los torbellinos significaría mayor mezcla de las propiedades del agua como el calor, salinidad y nutrientes… El océano Ártico tiene suficiente agua caliente al fondo como para derretir muchas veces la cobertura de hielo, pero esta está aislada de la superficie por las frías aguas superficiales (que tienden a flotar). La intensificación del proceso de mezcla vertical de este calor podría dar lugar a un mayor derretimiento de la cobertura de hielo. Los cambios en el mezclado de los nutrientes tienen impactos potenciales en los sistemas biológicos, en términos de la cantidad de nutrientes disponibles cerca de la superficie y en la temporada del año”.

Mark Jonhson, profesor de oceanografía física de la Universidad de Alaska, quien no está involucrado en el estudio, dijo que los cambios en las corrientes del Océano Ártico pueden alterar el clima en otras partes del hemisferio norte. Por ejemplo, dijo que el agua fría fuera de la costa de Groenlandia se hunde y debe ser sustituida por agua más caliente de la superficie que viene del sur. Esta convección trae el agua caliente de latitudes medias al norte, calentando a Europa un par de grados.

Mejorar los modelos es necesario

Tanto Armitage como Johnson afirmaron que este estudio destaca la necesidad de modelos oceanográficos con mayor resolución. Muchos de los modelos actuales no son capaces de resolver elementos tales como los eddies, y debido a que estos juegan un papel importante en la dinámica del giro de Beaufort, los modelos de mayor resolución son necesarios para obtener una mayor precisión. Tener estos modelos más precisos del Océano Ártico—y saber cómo se verá afectado por el cambio climático—es muy importante para las futuras predicciones del clima global.

El estudio fue publicado en febrero en Nature Communications.

—Hannah Thomasy (@HannahThomasy), Escritora de ciencias

This translation was made possible by a partnership with Planeteando. Esta traducción fue posible gracias a una asociación con Planeteando. Traducción de Itzel Y. Moreno Ramirez y editado por Alejandra Ramírez de los Santos.

A New View of Old Clouds

Thu, 04/16/2020 - 11:30

Marine shallow clouds are primary contributors to the uncertainties of climate projections. Bony et al. [2020], for the first time, provide an objective method to classify the mesoscale patterns of marine shallow clouds in satellite images. They show that surface wind and lower tropospheric stability are major factors that determine these cloud patterns.

As each cloud pattern is associated with different cloud radiative effect and cloud feedback to surface warming, this study illuminates a new path to improve the accuracy of climate change predictions—that is, studying cloud organizations and the processes that control these organizations.

Citation: Bony, S., Schulz, H., Vial, J., & Stevens, B. [2020]. Sugar, gravel, fish, and flowers: Dependence of mesoscale patterns of trade‐wind clouds on environmental conditions. Geophysical Research Letters, 47, e2019GL085988. https://doi.org/10.1029/2019GL085988

—Hui Su, Editor, Geophysical Research Letters

How Will Climate Change Affect Arctic Stream Slime?

Wed, 04/15/2020 - 11:28

Biofilms are hubs of microbial activity in streams. These complex matrices of algae, fungi, and bacteria—sometimes called “microbial skin” for their critical role in processing nutrients—adhere to streambeds in slippery mats. Despite their importance in biogeochemical processing in streams globally, researchers know very little about how stream biofilms in some parts of the world, such as the Arctic, respond to shifts in nutrient availability, a critical knowledge gap as climate change rapidly reshapes that part of the globe.

Indeed, the Arctic region is warming significantly faster than the global average. As permafrost thaws, microbes in the formerly frozen soil become more active, breaking down organic matter and releasing more nutrients into the environment, which can be carried away in seasonal meltwater. Here Pastor et al. study how changes in nutrient (e.g., nitrogen and phosphorus) availability in streams fed by thawing permafrost and seasonal snowmelt influence biofilm growth.

The team looked at two streams in Greenland’s Zackenberg Valley, a region of the High Arctic where summertime temperatures typically top out at about 4.5°C (40°F), and chose six sampling locations representing a broad range of hydrological conditions and nutrient concentrations. To measure biomass accrual, the researchers used glass disks—either untreated or preloaded with nutrients—as substrates to mimic surfaces in streams where biofilms would accumulate and placed these artificial substrates into the streams in the late summer, at the peak of seasonal thaws. Although many previous studies on stream biofilms measured biofilm growth by tracking only algal chlorophyll, the methods here also account for fungal and bacterial communities in biofilms. The team also monitored other stream conditions such as water temperature, flow velocity, and nutrient concentrations.

Overall, the researchers found that nitrogen concentrations, which are typically low in High Arctic streams, had a strong influence on biofilm growth. Biomass levels were highest at upstream sampling sites, where nitrate levels were up to 10 times higher than at downstream locations. The results suggest that climate change impacts in the Arctic, including the downslope flow of nutrients from soils, are likely to affect biofilm growth in the region’s streams. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2019JG005557, 2020)

—Kate Wheeling, Science Writer

The Art of Volcanic Ash Modeling 10 Years After Eyjafjallajökull

Wed, 04/15/2020 - 11:26

On 14 April 2010, the Icelandic volcano Eyjafjallajökull erupted explosively, hurling volcanic ash several kilometers into the atmosphere. Northerly winds then blew this dense plume toward Europe and the busiest airspace in the world. Over the next 6 days, hundreds of thousands of flights were canceled.

In the first week of the eruption, the closure of European airspace led to losses of approximately 1.3 billion euros (approximately $1.4 billion). In an attempt to stop the hemorrhaging, European aviation regulators turned to models of ash dispersal to determine where the plume was less dense and unlikely to damage airplane engines.

Scientists had only started to develop such models, however, and relied on knowing the intricate details about the eruption to perform the work. “But, in 2010, the amount and quality of the information about ongoing volcanic activity at the beginning of the eruption was quite low,” said volcanologist Sara Barsotti of the Icelandic Meteorological Office.

Moreover, European regulators decided that planes could fly on routes where the ash was below a certain level, but the modelers weren’t confident that their models could deliver the necessary degree of accuracy at each point of the journey, said Larry Mastin, a hydrologist at the U.S. Geological Survey (USGS) in Vancouver, Wash.

The 2010 experience, however, galvanized the community into striving toward creating more powerful models. “It became a technical challenge for the world’s modelers to be able to produce model output during an eruption that has meaningful airborne ash concentrations,” Mastin said.

Shattered Glass

Despite its name, volcanic ash isn’t the remains of burned material, like the ash left after fires.  Instead, it is far more deadly.

As magma rises underneath the volcano, tiny bubbles of carbon dioxide and water vapor form in it. When the magma can no longer hold the bubbles, they pop, driving the volcanic eruption. And once the sticky bubble walls reach the atmosphere, they cool into tiny shards of glass, less than a few millimeters in size.

When Eyjafjallajökull erupted, “the whole world changed in terms of how important it was to be able to forecast where ash clouds go.” Most of the ash from Eyjafjallajökull consisted of these bubble fragments, but ash can also be produced from the shattering of old rock during the eruption or can include mineral fragments that are contained in the magma. The tiny shards of broken bubbles are what typically cause the most damage to humans as well as planes, however.

“If you’re in a place that’s having heavy ashfall, it either forms cement in your lungs, which isn’t good, or it cuts your lungs,” said Erik Klemetti, a volcanologist at Denison University in Granville, Ohio. “As gruesome as it sounds, the deaths from volcanic ash are usually coming from people drowning in their own blood.”

Consequently, in the early 2000s, researchers around the world began to try and forecast where ash traveled or fell after an eruption. While in Italy, Barsotti helped develop the model in 2008, and by 2010, the USGS had developed their own model called Ash3d.

“By April 2010, it was just starting to work, and then of course, Eyjafjallajökull erupted,” said Mastin. “And then the whole world changed in terms of how important it was to be able to forecast where ash clouds go.”

A Meeting of Minds

In the early 1990s, the International Civil Aviation Organization began to set up nine Volcanic Ash Advisory Centers (VAACs) around the world to monitor and provide warnings to aircraft of volcanic ash in their region. Early on, the operators would scan satellite images to look for ash clouds, or once they heard of an eruption, they’d set their own rudimentary models running.

But to accurately model ash dispersal, the VAACs needed vital details on an eruption such as the height of the plume, the time the eruption started, and how long the eruption lasted. Consequently, volcanologists became involved, and the collaborations spurred improvements to the meteorological dispersion models used by most VAACs, along with development of volcano-specific models such as Ash3d.

When trying to determine how far ash travels, a key factor is how much ash is “coming out of the box” during an eruption, a quantity that is correlated with the height of the plume, Mastin said.  Another important factor is the grain size of the ash that is being erupted—smaller particles remain aloft longer and can drift farther.

“Having this system in place helps a quick response to an emergency.”Wind patterns determine how fast and far the ash is transported, requiring the input of hour-by-hour meteorological data at different heights and distances from the volcano. “The way that ashes are dispersed in the atmosphere is pretty complicated,” Mastin said. “It could be blowing in a completely different direction at several kilometers altitude than it is at low altitude.”

The VAACs have their own models, which they use to generate specialized warnings to the aviation community; researchers, volcano observatories, and weather services around the world are able to freely use Ash3d to generate ashfall warnings from eruptions in their region.

In Iceland, researchers now use the Numerical Atmospheric-dispersion Modelling Environment (NAME) ash dispersal model, developed by the UK Met Office integrated into a system that models a range of impacts expected from an eruption. The Icelandic Meteorological Office is continuously running simulations of eruptions of five high-threat volcanoes using current weather conditions with this software. “Having this system in place helps a quick response to an emergency,” Barsotti said.

Onward and Upward

Although researchers have improved their models in the past 12 years, techniques used to monitor many of the features of an eruption have also advanced, which also increases the model’s accuracy, Barsotti said.

Monitoring volcanoes for eruptions is essential to provide timely warnings, and even remote volcanoes that are under air traffic routes need to be monitored, said volcanologist Charles Mandeville, program coordinator of the USGS Volcano Hazards Program.

In March 2019, legislators passed a bill to fund the National Volcano Early Warning System in the United States, which will eventually result in increased monitoring of medium- and high-risk volcanoes in the country. “We have to get much better at optimizing the networks that are out on the volcanoes, to give us the earliest warnings possible,” Mandeville said.

The fact that modelers now have increased access to better quality monitoring data, as well as the opportunity to assimilate the observational data into the models, has improved their forecasts a lot, Barsotti said.  But ultimately, the biggest advancements in the past 10 years have come from the collaborations between scientists from many different disciplines.

“The volcanological community is now connected with the meteorological community, for example,” Barsotti said. “These connections will allow us to respond to the next eruption in a more workable and successful way.”

—Jane Palmer (@JanePalmerComms), Science Writer

An Element of Randomness in Modeling Arctic Ice Cover

Tue, 04/14/2020 - 12:39

Today, sea ice still covers much of the Arctic year-round, expanding during winter and shrinking in summer. But overall Arctic sea ice cover has been declining for decades, and it may one day disappear almost entirely. This decline has profound implications for ecology, shipping routes, and oil extraction throughout the region. However, climate models differ in their predictions of when, exactly, the Arctic might begin to experience ice-free summers and—decades later but more suddenly—ice-free winters.

Now Meccia et al. investigate a different strategy to assess uncertainties in Arctic sea ice predictions generated by a model known as EC-Earth. Their approach offers a computationally cheaper alternative to boosting the model’s resolution. Instead of trying to physically model air temperature, humidity, and wind on fine scales, the researchers introduced random, or stochastic, variations in these variables to help account for uncertainties in EC-Earth and provide predictions that could be more realistic.

The researchers ran the model for the years 1850 to 2160 with and without the stochastic variations under a “worst-case” greenhouse gas emissions scenario known as RCP8.5. Both approaches predicted an abrupt drop in wintertime Arctic sea ice cover around the year 2100. However, incorporating the random variability resulted in an approximately 10-year delay in the timing of this sudden collapse.

In the years approaching 2100, global temperatures predicted when the stochastic conditions were considered were lower than those predicted without the randomness. But after 2100, to the researchers’ surprise, global temperatures increased faster in the simulations with randomness than in those without. This acceleration may be due to an increase in high-altitude clouds seen in the simulations with stochastic variations after the disappearance of sea ice.

The research team is now exploring the underlying causes of the unexpected post-2100 temperature predictions. They also acknowledge that even with the introduction of the stochastic variations, significant uncertainties remain about climate feedbacks in EC-Earth, and further research is needed to understand and reduce them. (Geophysical Research Letters, https://doi.org/10.1029/2019GL085951, 2020)

—Sarah Stanley, Science Writer

Linking Hydrology and Biogeochemistry in a Tropical Urban Estuary

Tue, 04/14/2020 - 12:38

The San Juan Bay Estuary in Puerto Rico is an interconnected series of lagoons and canals that weave through San Juan, the capital city and home to nearly 350,000 people. As the city has boomed, the canals and waterways connecting the ocean with inland lagoons have grown clogged with sediment, trash, and debris. As a result, conditions look drastically different than they did even in the 1970s when residents first raised concerns about water quality in the estuary.

The challenges facing the San Juan Bay Estuary are typical of coastal, tropical urban areas around the world. Although coastal areas less than 10 meters above sea level represent only 2% of the world’s land area, they are home to 13% of the world’s urban population. These urban areas also tend to have low socioeconomic status and large populations vulnerable to storm surges and tropical storms associated with climate change.

In a new study of the San Juan Bay Estuary, Oczkowski et al. point out that surprisingly little is known about urban estuaries in tropical regions, especially given their prevalence and vulnerability. The authors evaluated nutrient cycling in the estuary, as well as how debris and sediment buildup in canals influence water quality in connected parts of the bay.

Through sediment analysis, the authors found that nitrogen fixation could be a significant source of nitrogen in the most urbanized parts of the estuary, where, for example, raw sewage enters the water. Much of the nitrogen fixation could stem from sulfate-reducing microbes, which are common in mangroves but have not been previously documented in urban systems. Furthermore, the nitrogen contributions from the bacteria appear to equal or exceed those from urban runoff and sewage.

The findings help to explain anoxic conditions, fish kills, and algal blooms that have occurred in parts of the estuary. The research also highlights how San Juan’s growth and lagging infrastructure have contributed to hydrological changes and an increase in residence time for nitrogen in the water.

The study is one of the first to link the biogeochemical and hydrologic conditions of the San Juan Bay Estuary. Although San Juan was the focus of this research, the study authors lay out a plan for conducting similar research in other urban estuaries around the world. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2019JG005502, 2020)

—Aaron Sidder, Science Writer

Nonscientists Struggle to Separate Climate Fact from Fiction

Tue, 04/14/2020 - 12:36

Can you recognize the truthfulness of simple statements about climate change? Are you sure about that?

A recent study asked 500 nonscientists to verify whether climate change statements were true or false and how confident they were that science agreed with them. The researchers found that nonscientists were underconfident in their knowledge of true statements about climate change­ but were overconfident in their ability to recognize statements as false.

“The confidence we have in our knowledge directs our decisions,” said Helen Fischer, a postdoctoral researcher in environmental cognition at the Stockholm Resilience Centre in Sweden. “If you have correct knowledge but you are not confident in that knowledge, then the accuracy of your knowledge doesn’t help. We need to be confident that it is correct to base our decisions on it.”

“If you have incorrect knowledge, this is doubly bad if you have high, unwarranted confidence in that knowledge.”Conversely, “if you have incorrect knowledge, this is doubly bad if you have high, unwarranted confidence in that knowledge, because then you will base decisions on wrong knowledge. We will make unfounded decisions.” These results were published in Nature Climate Change in September 2019.

Unwarranted Self-Doubt

The degree to which confidence in knowledge is matched by the accuracy of that knowledge is known as confidence accuracy. “For example,” the team wrote, “rejecting the statement that natural variation in sunbeams is the main driver of climate change shows accurate knowledge, but being uncertain about this rejection shows inaccurate confidence. Accepting the statement that greenhouse gas emissions are a main driver of climate change shows accurate knowledge, and being certain about this acceptance also shows accurate confidence.”

Confidence accuracy can be a powerful tool to assess people’s understanding in areas of knowledge that, like climate change, are rife with misinformation.Confidence accuracy can be a powerful tool to assess people’s understanding in areas of knowledge that, like climate change, are rife with misinformation. The researchers measured the confidence accuracy with regard to climate change of nonscientists in Germany by presenting them with statements about the state, sources, and consequences of climate change. For each statement, a person was asked whether science agrees with the statement and to rate their level of confidence in their answer from guessing (50% confidence) to absolutely certain (100% confidence).

For comparison, the team asked more than 200 climate scientists the same climate change questions and a different group of nonscientists questions about physical and biological sciences. These comparisons revealed how high nonscientists’ confidence accuracy could be with regular exposure to scientifically valid information and how high their confidence should be given their confidence in a similar topic.

The researchers found no significant difference in nonscientists’ confidence accuracy with regard to the state, sources, or consequences of climate change. “The most striking result,” Fischer said, “is how bad [nonscientist] citizens are at telling what they know and what they do not know about climate change compared with how good they are at telling what they know and do not know when it comes to general science.”

“For the false statements, citizens appeared to have no insight into the fact that they did not know.”On true statements, nonscientists’ confidence in their climate change knowledge was only about half what it could be on the basis of the accuracy of that knowledge—they knew the right answer but didn’t trust that they did. This doubt was greater than for nonscientists’ general science knowledge and for climate scientists’ knowledge.

However, nonscientists sometimes were unable to verify 60% of the false statements about climate change yet were very confident that they had done so. This trend was seen only for nonscientists on climate change.

Even when considering that someone might just know more about physics or biology than about climate change, nonscientists were “disproportionately bad” at assessing the limits of their climate knowledge, Fischer said. “For the false statements,” the team wrote, “citizens appeared to have no insight into the fact that they did not know.”

Katharine Hayhoe, a climate scientist at Texas Tech University in Lubbock, said that “while the first half of the results of this study are encouraging—that people were able to correctly identify true statements and felt confident about their ability to do so—the second half of this study—that they were not as able to identify the false statements even when they felt confident they in their answers—is discouraging but not surprising.”

The Impact of Misinformation

“There is no question that misinformation increases people’s uncertainty regarding what is and what is not true,” Hayhoe said. “When strong statements are made by perceived experts or thought leaders who we respect, we tend to assume they are true. Today, however, we are being fed false information about climate change on a near-daily basis.”

Fischer noted that this research tested only German citizens and that the results might be different in countries with different educational, political, and media landscapes. Future research aims to assess whether confidence in climate change knowledge correlates with belief in climate change, how people’s confidence differs before and after their exposure to misinformation, and how that confidence changes over a long period of time.

“There has been a large, long-lasting effort to criticize the science of climate change,” said climate researcher Richard Alley of Pennsylvania State University in University Park. “There is scholarship…showing that so-called ‘skeptical’ scientists have greater public exposure than mainstream scientists, so that the public message received by a large fraction of the population is that scientific uncertainty and scientific debate are much larger than they really are.”

“The take-home message is that increasing knowledge is not enough.”“If people are not confident that scientists agree,” Alley said, “it might not be surprising that people are not confident of their own understanding.”

“If we appear very confident, this affects others,” Fischer said. “This is very risky. If someone has low knowledge but high confidence, then this will influence others, and then wrong climate change knowledge can have strong network effects, for example, with the media or the Internet.”

Although this study was not able to assess the degree to which misinformation about climate change led to the true/false gap in confidence accuracy, she said, it did underscore an important point: “The take-home message is that increasing knowledge is not enough,” she said. “What has been done a lot is to try and increase citizen’s knowledge about climate change. Now, the knowledge is out there. [People’s] knowledge is not so bad.”

“The next step is to increase confidence,” Fischer said, “not just in accurate statements but also such that people know what is true and what is untrue with high confidence. So that when they see a false statement they confidently know, ‘No. I know very certainly this is false.’”

—Kimberly M. S. Cartier (@AstroKimCartier), Staff Writer

This story is part of Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.

Ocean Gyres Observed to Move Poleward

Tue, 04/14/2020 - 11:30

Ocean gyres are basin-wide currents that redistribute mass, heat, salt, nutrients, and other properties from low to high latitudes. These large-scale wind-driven circulation systems are typically characterized by strong boundary currents along the continental coastal margins with more sluggish flow in the central sections of the gyres.

The gyres often have an outsized role in transporting biogeochemical nutrients that maintain ecologically and economically important marine ecosystems as well as play a critical function driving the atmospheric circulation particularly in the subtropics.

Yang et al. [2020] find that the global oceanic gyres have been slowly shifting poleward over the past four decades. Both anticyclonic subtropical gyres, identified by centers of relatively high sea surface height (SSH) and cyclonic subpolar gyres with centers of low SSH, advanced poleward on the order of around 0.04-0.1 degrees latitude per decade.

Similar poleward trends were observed in the strong sea surface temperature (SST) gradients that mark the boundaries between the subtropical and subpolar gyres. While the poleward trends in the southern hemisphere ocean gyres were significant, many of the poleward trends in the northern hemisphere gyres were not statistically significant and could not be distinguished from natural climate variability.

Nonetheless, climate model simulations suggest that a warming world would drive a poleward shift in the winds consequently displacing the oceanic gyres poleward. This shift could have important consequences for the overlying atmosphere impacting jet streams and storm tracks that influence near-term climate variability. Thus, it is important that oceanic observations are continued, and simulations are performed to investigate the time-line and magnitude of these changes and to further verify their robustness.

Citation: Yang, H., Lohmann, G., Krebs‐Kanzow, U., Ionita, M., Shi, X., Sidorenko, D., et al. [2020]. Poleward shift of the major ocean gyres detected in a warming climate. Geophysical Research Letters, 47, e2019GL085868. https://doi.org/10.1029/2019GL085868

—Janet Sprintall, Editor, Geophysical Research Letters

The Long-Term Effects of Covid-19 on Field Science

Mon, 04/13/2020 - 19:52

This article was originally published on Undark. Read the original article.

March 31, 2020 by Claudia Geib

If this winter had gone as planned, Bethany Jenkins would be getting ready to board a 274-foot research vessel called Atlantis right about now to head east across the Atlantic Ocean. But everything changed when the novel coronavirus SARS-CoV-2 began to infect people worldwide and touched down on U.S. shores. In mid-March, the University of Rhode Island microbiologist received word that her team’s trip had been suspended. The future of their research project — a three-ship, multi-institution investigation of ocean ecosystems that has been over a decade in the works — is now uncertain.

But as Jenkins and her team begin to pick up the pieces, she doesn’t like considering what might have happened if the trip had gone ahead.

“The people on these ships leave their families behind,” she said. “If I’m at sea, I won’t be able to help anyone on land.” The opposite is true as well: “On these research cruises, there are four people sharing each bathroom, mates sharing a wheelhouse, professional crew in the engine room and sharing berths. If something went wrong, it would be really bad.”

As the coronavirus has spread, reaching every continent except Antarctica and infecting over half a million people, scientific institutions all around the world have shut down or suspended field research like Jenkins’, leaving many of these scientists’ work in limbo. Governments and health officials have told people to try to work from home using remote communication tools. But for the most part, field scientists can’t do that; their projects rely on gathering new information out in the world. Unfortunately, many attributes of field research — international travel, limited access to medical testing or care, long periods spent sharing close quarters — are also the very things that can help the coronavirus spread.

This halt has left scientists feeling stranded, uncertain of the future, and with more than a few logistical headaches. As grants approach their completion dates and researchers miss out on once-a-year or even once-in-a-lifetime observations, they’re beginning to grapple with how this temporary crisis will have permanent reverberations in the scientific community. The path forward for students and junior researchers, who rely on fieldwork to learn essential skills and collect data to begin research of their own, is now filled with obstacles, creating a knock-on effect for future scientific expertise. What’s more, the pause may mean delays for important advancements in many areas, from fighting climate change to preventing the next pandemic.

Field research often can’t simply be pushed off by a few months; by then, the natural events scientists are meant to observe may have already ended.“Right now, we’re in a time of acute societal need that requires good science,” said Jenkins. “So there’s a real mandate to keep going forward with good science, while being empathetic with the health of the people that are really struggling during this.”

“You can’t Skype meetings with corals,” said Emily Darling, a scientist with the Wildlife Conservation Society, who coordinates monitoring for increasingly threatened coral reefs all over the globe. “Being underwater, and being with the communities that rely on reefs, is the only way we have information about the health of a reef. That information is not available remotely.”

Right now, though, human health is Darling’s priority. Her team has canceled travel to their study sites, asking all researchers to stay at home for the time being. She was particularly worried about team members visiting remote villages in countries like Kenya and Fiji, where communities might be isolated from the coronavirus until an outsider carries it unwittingly into their midst.

“While our national staff might have access to health care in urban centers, they’d be traveling into communities that don’t have that same level of care,” she said.

As her researchers shelter in place, life in the sea churns on, and Darling knows they’ll miss out on important observations. One concern is that they may not be able to adequately monitor an outbreak of a different kind this spring: an often-fatal reaction to high ocean temperatures called coral bleaching, which is currently moving across the warming South Pacific. Some information can be gathered by flying above reefs in small aircraft, but few institutions currently have access to such flights, nor do they want to expose their researchers to the cramped quarters of a bush plane.

Got questions or thoughts to share on Covid-19? Email Undark at covid19@undark.org.

The nature of field work makes it difficult to reschedule around delays. Field research often can’t simply be pushed off by a few months; by then, the natural events scientists want to observe may have already ended. And research vessels and field stations might be shared by hundreds of institutions, requiring scientists to get in line years in advance.

Take the case of Jenkins’ research trip, part of a broad NASA-led effort called Exports, or Export Processes in the Ocean from Remote Sensing, that’s seeking to investigate how the oceans take up and store carbon from the atmosphere (including climate-warming carbon dioxide), potentially for thousands of years. Their cruise would have monitored tiny, floating ocean plants — phytoplankton — that have their biggest bloom in the North Atlantic for only a few weeks in the spring. Because any projects currently planned for after the quarantine will still go ahead, it will likely be at least two years before her team can book a new trip.

Over the coming months and years, delaying field work also means delaying the publications that would have come out of it. Down the line, that could affect policy decisions that would ideally be based on the best and most current scientific data. This is especially concerning for scientists and policymakers tackling issues that are already on borrowed time — like in the case of Exports, which is collecting data that will allow more accurate predictions of global climate change.

With hundreds to thousands of other projects also put on pause, Jenkins sees how echoes of this shutdown will spread through the field of climate science: “If field programs that measure climate-relevant variables are being canceled or put on hold, this is a step backwards for our contributions to understanding a rapidly changing ocean.”

Ravinder Sehgal, an associate professor in the biology department at San Francisco State University, worries that delays in his field due to coronavirus could hinder the collection of data that might help prevent the next pandemic. Sehgal studies how deforestation allows disease to spread from animals to humans, and his field work, which includes following the spread of malaria by mosquitoes and birds in Cameroon, is currently suspended. Projects like his all over the world rely on detailed timelines of how diseases progress that will now likely feature gaps of months to years.

“Without the continuity of yearly monitoring of populations, we don’t have the data we need for long-term study,” he said.

Like most science, field research often relies on grant funding that is given only for a specific time period. Because of this, chief among many scientists’ concerns is how project delays will impact early-career scientists, including Ph.D. students and postdoctoral researchers.

When principal investigators apply for a project grant, they often will request funding to support a Ph.D. student or a postdoctoral researcher. These funds may now expire before students can gather the data needed to finish their degrees or leave postdocs without a salary while they are still working on a project.

Matthew Smart could finish his degree without completing his field research, “though it would be a tremendous disappointment,” he said. A Ph.D. candidate in geochemistry at Indiana University-Purdue University Indianapolis, Smart planned to complete his dissertation using data from a trip to eastern Greenland scheduled for this summer. His research uses samples from a particularly well-preserved outcrop of rocks there to learn about what happened when Earth’s ancient plants developed roots and began to make soil. But that trip is only possible during a short window from August to September when the study site is not blocked by ice.

Smart is still holding out hope, but he said it’s becoming increasingly likely the work will be canceled. That will push him and his adviser past the time limits on the grants funding their work, meaning Smart likely won’t be a student anymore by the time he returns to Greenland.

“There’s a significant health element to this crisis that trumps science, frankly,” Smart said. “We have to make sacrifices in order to ‘flatten the curve,’” he added —in other words, keep the rate of infection low enough to avoid overburdening health systems.

Some grant-funded projects may be able to extend their funding to make up for lost time. For example, all National Science Foundation grants are automatically eligible for a one-year no-cost extension, as well as additional extensions contingent on the foundation’s approval. Many universities and private foundations are developing special exceptions for research delayed by the Covid-19 pandemic.

However, these extensions don’t necessarily guarantee any additional money — just extra time. This could leave research teams in a tight spot, especially if a grant must cover salaries during the delay in addition to travel expenses.

Darling, though, sees the pandemic in another light: as an opportunity for scientists to rethink some of the ways they carry out field research.“If this continues for long enough, my main concern is that students will either drop out of their research altogether or move to other fields,” said Sehgal. “They can’t afford to not be doing anything.”

Like the hundreds of millions of others around the world currently held in stasis outside of normal life, scientists are thinking about the future of their work in the space between communal sacrifice and self-interest. Interruptions to normal habits are necessary, and they’re saving lives. But it’s also understandable to process the conditions of this social contract through a personal lens: as disappointing, frustrating, and worrying.

The Wildlife Conservation Society’s Darling, though, sees the pandemic in another light: as an opportunity for scientists to rethink some of the ways they carry out field research. Her organization already relies chiefly on researchers based in-country, rather than flying in scientists from elsewhere in the world. That’s a model she sees as potentially helpful for other projects.

One big benefit of doing this is that it reduces their research’s carbon footprint, but that’s not the only advantage. “We know so much about the inequity of scientific resources and training, where Western researchers can travel and fly and do ‘helicopter science,’” Darling said, using a term for when a researcher spends only a brief stint in a place to gather data before heading home.

“That’s not a model that’s sustainable, and it’s not a model that’s ethical,” she said. “So this new reality gives us a chance to develop online tools for collaborations, for conferences, for workshops, and identify where we really need to travel and be face-to-face with our work.”

For now, most researchers are still trying to get a grip on the situation before beginning to plan for the future. They’ll teach classes remotely, revise their writing, and read long-put-off papers. They’ll look for ways they can help. Many are donating gloves, masks, and chemicals that they now won’t need for their work. Some are volunteering their expertise on the ground. Given their training in microbiology, Jenkins and some of her colleagues have signed up to assist with Covid-19 testing.

And they’ll wait — perhaps missing the dramatic sweep of Arctic landscapes or the stark beauty of the middle of the ocean, but staying focused on the present.

“We’re really hoping that this passes, as I’m sure the rest of the world is, so we can get back out there,” Darling said. “But this is a fast-moving crisis, and we need to take care of people first.”

This article was originally published on Undark. Read the original article.

How Accurate Are Our Measurements of the Sun’s Energy?

Mon, 04/13/2020 - 11:47

At first glance, the Sun’s burning heat seems to be unvarying. To explain the differences we experience, we tend to point to cloud cover, humidity, or the dynamics of our atmosphere. However, as the Sun progresses through its 11-year cycle of activity and quiet, as well as its 27-day rotation, the radiation it bestows on Earth changes.

An instrument called the Spectral Irradiance Monitor (SIM) aboard the Solar Radiation and Climate Experiment (SORCE) satellite monitors how much solar energy bathes Earth across a range of wavelengths from the ultraviolet to the near infrared. Knowing the distribution of solar energy across this spectrum can help scientists track where on Earth this energy is absorbed, a key factor in climate change estimates. However, exposure to harsh solar radiation at shorter wavelengths causes the satellite’s instruments to degrade, meaning researchers must adjust for the aging equipment to keep recording accurate measurements.

In pursuit of this accuracy, Mauceri et al. compared three methods of correcting SORCE SIM measurements: SIM version 25, Multiple Same-Irradiance-Level, and SIM constrained version 2 (SIMc V2). They then compared the results of these corrective methods with four independent measurements of solar energy and with two solar energy models.

The researchers found that solar energy measurements from the three correction methods matched most closely for—and were therefore most accurate for—visible light wavelengths. They also observed some surprising variation in near-infrared wavelengths, where instrument degradation is small and thus a high level of agreement between the three methods was expected. The discrepancy may be a result of artifacts from corrections made for shorter wavelengths.

The team found the greatest variation among measurements at high-energy ultraviolet wavelengths, which also cause the most damage to the instruments. Earth is more sensitive to variations in the amount of ultraviolet radiation it receives than to variations of other wavelengths. To ensure accurate climate models, future correction methods must thus maintain accurate short-wavelength observations. Of the three correction methods for SORCE SIM data, the researchers recommend SIMc V2 for most applications, but they noted that continued research and development are still needed. (Earth and Space Science, https://doi.org/10.1029/2019EA001002, 2020)

—Elizabeth Thompson, Freelance Writer

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