Bat guano can record local fire history, a new Geophysical Research Letters study finds. Bats collect charcoal on their bodies when foraging in burned areas, and later ingest it when grooming. Credit: USFWS/Alvarez Photography

AGU News 

AGU24 press registration 
Press registration for AGU’s Annual Meeting is open! AGU24 will be held in Washington, D.C. from 9-13 December. Complimentary registration is available for journalists, journalism students, press officers, and institutional writers covering the meeting. Discounted housing is available through 11 November. [register here][eligibility][AGU24 press center][hotel information] 

Featured Research

Bat feces record fire history 
Fires are recorded in an unlikely medium: bat feces. New research analyzed bat guano cores from a limestone cave in Tennessee and found that charcoal preserved in the guano, ingested by bats foraging in burned areas, accurately recorded local fire history from the 1950s to present. The researchers were also able to distinguish between human-caused and natural fires recorded in the guano. [Geophysical Research Letters study] 

Hazards research focuses on areas with wealth, not risk 
Research on floods, droughts and landslides focuses disproportionately on wealthy countries, as opposed to countries with the highest risk from those hazards, reflecting a “wealth over woe” bias, according to a new study. Less work tends to be done in low-income, high-population areas — even those known to have higher hazards. [Earth’s Future study] [Potsdam press release] 

Dusty clouds keep the Arctic cooler 
Dust may play an important role in Arctic cloud formation and Arctic surface temperatures. New research finds that dust aerosols can push clouds into the ice phase, cooling the underlying land more than clouds in the liquid phase. That cooling effect intensifies as the dustiness of the clouds increases. [Geophysical Research Letters study] 

Madrid’s urban heat islands expected to grow 
Urban heat stress is expected to increase as the climate warms. A new study identified already-vulnerable areas in Madrid, Spain, using factors such as population age, education status and socioeconomic status, and found that those areas will expand in the future. [Earth’s Future study] 

Stratospheric aerosol injections could alter wind power 
Stratospheric aerosol injections are a geoengineering technique that could lower global temperatures, but also cause unintended consequences. New research finds that while the global potential for wind renewable energy would be largely unaffected by stratospheric aerosol injections, regional trends could increase or decrease by up to 12% worldwide. [Earth’s Future study] 

Machine learning could improve extreme weather warnings 
A deep learning technique could reduce the error in 10-day weather forecasts by more than 90%, allowing communities to better prepare for extreme events such as heat waves. [Eos research spotlight] [Geophysical Research Letters study] 

New details emerge about a very old eruption and flood 
One of the most dramatic volcanic eruptions in history occurred more than 1,000 years ago at Changbaishan, on the border of China and North Korea. In a new study, scientists dig into the catastrophic flood that followed the eruption, aiming to better predict modern risks if such an eruption occurred again. [Eos research spotlight] [Water Resources Research study] 

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Microplastics from car tires could increase melt in Colorado snow, a new JGR Atmospheres study finds. Credit: Unsplash/Autumn Mott Rodeheaver

AGU News

AGU24 press registration 
Press registration for AGU’s Annual Meeting is open! AGU24 will be held in Washington, D.C. from 9-13 December. Complimentary registration is available for journalists, journalism students, press officers, and institutional writers covering the meeting. Discounted housing is available through 11 November, but housing is almost full. [register here][eligibility][AGU24 press center][hotel information] 

Featured Research 

Research roundup: Hurricanes and storm surges 
Hurricane Milton is bearing down on the Gulf Coast of Florida. Read up on the latest hurricane and storm surge research. 
[land subsidence and storm surge along Florida’s Gulf Coast] [contaminant movement after Hurricane Florence] [Hurricane Michael storm surge analysis] [climate change impacts on hurricane season length] [improving storm surge monitoring] 

Shredded tires speed snow melt 
Microplastics enter the air when road tires degrade during driving. New research finds that snow near high-elevation roads in Colorado contained microplastics mixed in with small black particles from shredded tires. Those black particles could amplify the effects of surface-warming atmospheric black carbon by 10% to 30%, increasing ice and snow melt. [JGR Atmospheres study] 

Atacama mine tailing dust travels far from its source 
Mining operations in Chile’s Atacama Desert have created large mine tailing deposits. New research finds that arsenic-contaminated dust can travel up to 70 kilometers (44 miles) from mine sites, and that soil arsenic levels downwind of mine sites may be 11 times greater than natural conditions. Copper and molybdenum dust also traveled up to 50 kilometers (31 miles) from mine sources. The research has implications for the health of local Indigenous communities. [GeoHealth study] 

Hunga Tonga water vapor could boost stratospheric humidity for years 
The January 2022 Hunga Tonga/Hunga Ha’apai eruption blasted 150 million tons of water vapor into the stratosphere. New research finds that the humidity of the stratosphere has not decreased since, and could stay elevated for as few as five to as many as 18 years. [Geophysical Research Letters study] 

Planted forests in China green slower 
Planted forests cover 80 million acres in China. New research finds that planted forests greened 7% slower than natural forests across South China. Slower greening indicates lower rates of productivity and sluggish carbon cycling. [Geophysical Research Letters study] 

Indo-Pacific mangroves show seaward gains 
Mangroves in the Indo-Pacific are expanding seaward due to coastal sediment accumulation, while decreasing in upland areas due to human development, new research finds. Those increases could offset up to 67% of the upland decreases. The seaward gains will eventually be stymied by sea level rise. [Geophysical Research Letters study] 

Mental health hospital visits increase during heatwaves 
Heatwaves aligned with an increase in mental health hospital visits in Guangzhou, China from 2010 to 2014, according to new research. Heatwaves lasting longer than four days were associated with more hospital visits, and older adults were more affected than younger adults. [GeoHealth study] 

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Climate change is causing storms to change around the world, a new Earth’s Future study finds. Credit: Unsplash/Beau Horyza

AGU News

AGU24 press registration 
Press registration for AGU’s Annual Meeting is open! AGU24 will be held in Washington, D.C. from 9-13 December. Complimentary registration is available for journalists, journalism students, press officers, and institutional writers covering the meeting. Discounted housing is available through 11 November, but housing is almost full. [register here][eligibility][AGU24 press center][hotel information] 

Featured Research 

Storms in the tropics are intensifying as climate warms    
Climate change is altering storm patterns globally, according to new research. Storms in tropical regions are becoming shorter with more concentrated rainfall, while temperate storms are becoming more dispersed and lasting longer. [Earth’s Future study] 

Post-drought precipitation to increase this century 
Periods of high precipitation after drought can increase natural hazards, such as landslides, and agricultural losses. A new study finds that post-drought precipitation could increase by approximately 15% globally by the end of the century, especially in the autumn. [Geophysical Research Letters study]

Great Dismal Swamp has lost 50 million metric tons of carbon since the 1700s 
The Great Dismal Swamp is a peat swamp in Virginia and North Carolina. Humans have disturbed the swamp for hundreds of years, starting with drainage in the 1700s. New research finds the swamp has lost around 50 million metric tons (approximately 55 million U.S. tons) of carbon since the colonial era. Two peat fires in 2008 and 2011 caused an additional one million metric tons (approximately 1.1 million U.S. tons) of carbon loss. [JGR Biogeosciences study] 

Perserverance samples could reveal history of Mars’ ancient magnetic field 
Mars does not currently have a magnetic field, but it did have one almost 4 billion years ago. But when and why did it disappear? New research finds that samples collected by the Perseverance rover likely contain ferromagnetic minerals, which should tell researchers more about Mars’ magnetic past. [JGR Planets study] 

Pollution from Indian biomass burning absorbs solar radiation 
Brown carbon, a type of aerosol released during biomass burning, can reflect sunlight. However, it can also absorb radiative energy and contribute to climate warming. Researchers deployed air filters and used satellite data to find that brown carbon particles from residential cooking, agricultural burning and other industries may absorb large amounts of solar energy over India. [Geophysical Research Letters study]

The Moon’s tides hint at a melty lunar layer 
New lunar gravity measurements support the idea that a partially molten mantle layer is sandwiched between the rest of the Moon’s mantle and its core. [Eos research spotlight] [AGU Advances study]

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Extreme summer rainfall events are increasing in the U.S., mostly in the upper Midwest and along the East Coast, a new Geophysical Research Letters study finds. Credit: Unsplash/ Dave Hoefler

AGU News 

Press registration for AGU’s Annual Meeting is open! AGU24 will be held in Washington, D.C. from 9-13 December. Complimentary registration is available for journalists, journalism students, press officers, and institutional writers covering the meeting. Discounted housing is available through 11 November, but rooms are filling up quickly. [register here][eligibility][AGU24 press center][hotel information] 

Featured Research

Extreme rainfall events becoming more common in the US East Coast and Midwest 
Extreme rainfall events occur when the amount of rain that falls over 12 hours is only exceeded approximately once every ten years. A new analysis of summer rainfall data from 2003-2023 finds that the number of extreme rainfall events have increased over time, especially at night along the East Coast and in the Midwest. [Geophysical Research Letters study] 

Climate change has changed precipitation patterns in North America 
The continent’s water cycle has already been dramatically affected by climate change. Northern regions of the U.S. and much of Canada have gotten wetter, the southern U.S. and Mexico have gotten drier and differences between extreme water years have grown, according to new research. The study examined tree rings, weather observations and model simulations to reconstruct annual water cycles from 850 CE to project the water cycle in 2100 CE. [The Ohio State University press release] [Geophysical Research Letters study] 

Wildfire smoke spews hundreds of types of microbes into the air 
Bacteria found in plumes of wildfire smoke mostly come from burned vegetation and soil, a new study finds. The study was carried out during a controlled burn in an aspen-dominated forest in Utah, launching 403 types of microbes into the air. The researchers estimated that smoke from the controlled burn could contribute approximately 25% of the bacteria found in nearby areas. [JGR Biogeosciences study] 

Heatwaves in coral reefs in the South China Sea are getting more frequent, but weaker 
The South China Sea has experienced more frequent and drawn-out heatwaves over the last 40 years. New research finds that coral reefs in the South China Sea are experiencing weaker, but more frequent heatwaves, possibly due to a negative feedback loop between the sea surface and clouds. [JGR Oceans study] 

Some regions to experience dramatic wetland declines by the end of the century 
Wetlands have shrunk by up to 50% globally since 1900. By 2100, wetlands may decrease by an additional 28% in the western Amazon Basin and by 13% on average above 50 degrees North, according to new research. [Earth’s Future study] 

Volunteers track Parisian pollution with the help of tree bark 
Participants in the Ecorc’Air project are using magnetic particles deposited on tree bark to reveal local traffic pollution patterns. [Eos Research Spotlight] [Community Science study] 

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Erosion caused by wildfires has been increasing since the 1980s, with most topsoil sediment produced in the last decade, a new JGR Earth Surface study finds. Credit: Wikimedia Commons/ Vulpinus2/ CCA BY-SA 4.0

AGU News 

Press registration for AGU’s Annual Meeting is open! The meeting will be held in Washington, D.C. from 9-13 December. Complimentary registration is available for journalists, journalism students, press officers, and institutional writers covering the meeting. Discounted housing is available through 11 November, but rooms are filling up quickly. [register here][eligibility][AGU24 press center][hotel information] 

Featured Research

Wildfires dump sediment into California’s already stressed water reservoirs 
Wildfires reduce the amount of vegetation on hillslopes, increasing erosion when it rains. New research finds that hills in California have been eroding more after wildfires since the 1980s, especially upstream of reservoirs, which could muddy the state’s clean water supply. [JGR Earth Surface study] [USGS press release] 

Comprehensive report finds European emissions reductions are hampered by land use changes 
Europe successfully controlled its greenhouse gas emissions between 2010-2020. However, the land’s ability to take up carbon dioxide has also decreased since the early 2000s, especially in Scandinavia due to mature forest cutting. In contrast, sink capacity has actually increased in parts of Eastern Europe and Northern Spain. Highlights include: 

• Europe emits a net 3.9 billion tons of carbon dioxide equivalents each year, 85% of which is from fossil fuel combustion 

• European emissions declined by 1.2 billion tons of carbon dioxide equivalents between 2010-2020, due to decreases in fossil fuel use 

• While the land absorbs 0.9 billion tons of carbon dioxide equivalents each year, its sink capacity has decreased since the 2000s [Global Biogeochemical Cycles study] 

Trees are increasingly vulnerable to precipitation changes 
Trees are becoming more sensitive to both increases and decreases in precipitation, which could increase tree death. Since 1950, trees in both moist and dry environments have become more sensitive to changes in precipitation and increasing carbon dioxide levels. [Geophysical Research Letters study] 

Black, Hispanic communities in rural and urban areas face most PM2.5 exposure 
Exposure to air pollution is linked to a wide range of poor health outcomes. An analysis of PM2.5 air pollution across the United States found that rural areas generally had lower levels than urban areas, and that both urban and rural areas that were majority Black, Hispanic and in poverty had worse air pollution than other areas. [GeoHealth study] 

Human activities are causing additional land subsidence and potential flooding along the Gulf Coast 
The Gulf Coast is already prone to flooding from storm surges. New analysis of coastal land subsidence reveals widespread millimeter-scale subsidence from oil and gas production, groundwater pumping and wetland loss that could dramatically increase flooding along the coast. [JGR Earth Surface study] 

Northern Hemisphere lakes could lose up to 28 days of ice cover by end of century 
New research analyzed community science data across 15 countries from 1971-2020 and found that lake ice cover has decreased by an average of nine days per decade. By the end of the century, lake ice cover could decrease by 10-28 days annually depending on climate warming scenarios. [Water Resources Research study] 

Marine cloud brightening geoengineering in the Pacific could cool Africa 
A form of geoengineering in which salt aerosols are injected into the atmosphere could have far-reaching consequences. A new study finds that marine cloud brightening deployed over the Southeast Pacific could cool Africa, blunting extreme drought and precipitation. [JGR Atmospheres study] 

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The Atacama Desert has very few dust storms or dusty days, even though it is the driest non-polar desert on Earth, a new JGR Atmospheres study finds. Credit: Wikimedia Commons/ Luca Galuzzi/ CC BY-SA 2.5

Featured Research

The Atacama Desert is dry, but not dusty 
The Atacama Desert is one of the driest places on Earth, but a new study reveals it’s not as dusty as we thought. There are fewer than two dust storms per year in the desert on average, and there have only been around 2,000 dusty days in the Atacama over the last 72 years. [JGR Atmospheres study] 

Flesh-eating aquatic bacteria flourish in the Gulf of Mexico’s warming waters
Vibrio vulnificus is a dangerous bacterium found in warm, mildly salty waters. New research finds that infections from the bacteria increase in the Gulf region after periods of high sea surface temperature and high chlorophyll levels, a proxy for zooplankton concentration. [GeoHealth study]

Per- and poly-fluoroalkyl substances from e-waste disposal may affect breast milk steroid levels 
E-waste disassembly centers release PFAS compounds into the surrounding environment. According to a new study, mothers living near e-waste facilities in China have breastmilk with altered steroid hormone levels, and the PFAS consumption of their breastfeeding infants is higher than recommended. [GeoHealth study] 

Alaskan glacier creates natural climate change experiment 
A glacier advanced toward Alaska’s La Perouse forest during the Little Ice Age (1850-1895) and then retreated away from the forest due to climate change (post-1950). Using tree ring analysis, a new study finds that five of the forest’s dominant tree species began to grow at different rates from each other during these periods of rapid temperature change, leading to greater overall forest stability. [Geophysical Research Letters study] 

Brown carbon contributes to China’s pollution problems 
Brown carbon enters the atmosphere from both biomass burning and residential cooking and heating. New research finds that brown carbon makes up approximately 19% and 12% of the light absorption of polluting aerosols in China’s atmosphere in the summer and winter, respectively, contributing to local warming. [Geophysical Research Letters study] 

European heat waves boosted by atmospheric circulation changes, aerosol reductions 
In recent years, Europe has experienced more heat waves than average compared to the rest of the globe. Those heat waves are partially caused by human-induced atmospheric circulation changes and reduced aerosol emissions in Europe, new research finds. [Geophysical Research Letters study] 

Eliminating the “free river” loophole could reduce the Colorado River’s water crisis 
When all water users in the Colorado River Basin have sufficient water supply, Colorado declares the river and its tributaries to be under “free river” conditions. During free river conditions, both permitted and non-permitted users may take as much water as they like from the river. Closing the free river loophole may help alleviate the drought in the basin, where water levels in Lake Mead and Lake Powell were 75% empty at the beginning of 2023. [Water Resources Research commentary] [University of Virginia press release] 

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Marine heatwaves and “super-heatwaves” contributed to 2023’s record-breaking ocean temperatures, new Geophysical Research Letters research finds. Credit: Wikimedia Commons/ National Marine Sanctuaries

Featured Research
Marine “super-heatwaves” shattered temperature records in 2023
Marine heatwaves and “super-heatwaves” helped break sea surface temperature records during the spring and summer of 2023. The heatwaves were caused by a combination of climate change, a shift from La Niña to El Niño and long-term changes in large ocean water masses, new research suggests. [Geophysical Research Letters study] [NOAA press release] 

Springtime bedrock water withdrawals sustain Sierra Nevada vegetation
Water is scarce in the dry Sierra Nevada mountains. New research finds that plants in the region may exhaust soil moisture and begin drawing water from the bedrock as early as April, and not in the late summer as previously thought. [Water Resources Research study] 

Sea level rise and high river flows could flood St. Lawrence River 
The combination of sea level rise and high river flow can lead to flooding for coastal communities. New research finds that these combined events could increase flooding in inland regions of Canada’s St. Lawrence River, while sea level rise alone may increase flooding chances by 50 times in coastal regions. [Earth’s Future study] 

Sparse spring rains lead to a dry Colorado River 
Colorado River flow estimates based on snowpack have consistently overestimated water levels. New research finds that decreases in spring rainfall have led to low stream flows, as vegetation takes up available water before it reaches streambeds. [Geophysical Research Letters study] [University of Washington press release]  

Amazonian drought may have long-lasting effects on carbon cycle 
Dry conditions stemming from the 2015–2016 El Niño caused significant carbon loss. [Eos reseach spotlight][AGU Advances study]  

Drought-induced tree mortality may turn Amazon into carbon source
Persistent dry conditions in the Amazon rainforest put trees at risk of dying, potentially causing the forest to a transition from being a carbon sink to source by the 2050s. [Eos research spotlight][Earth’s Future study] 

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A May 2024 coronal mass ejection caused one of the strongest geomagnetic storms ever observed by NASA’s SABER instrument, according to new Geophysical Research Letters research. Credit: Wikimedia Commons/ NASA

Featured Research 

May 2024 geomagnetic storm was one of the strongest since 2002
A coronal mass ejection, or a large explosion of plasma from the Sun, hit Earth’s high atmosphere between May 10-13, 2024. The subsequent geomagnetic storm was one of the strongest observed in the last 22 years, causing infrared radiation levels to increase by almost tenfold globally. [Geophysical Research Letters research] 

Reservoir modifications could help fish flow
Dams and reservoirs can disrupt fish migration paths along natural rivers and streams. New research modeled how modifying reservoir releases at the Danjiangkou Reservoir in central China could improve migration for four economically valuable carp species. [Water Resources Research research] 

El Niño kickstarts many heatwaves in India
Heatwaves in India impact human health and agriculture and are strongly influenced by El Niño events. New research suggests that most pre-monsoon Indian heatwaves begin in the country’s northwest region, and then move toward the country’s northeast and southeast regions. While southward-moving heatwaves are often influenced by El Niño, central and northern heatwaves can be more intense due to local meteorology. [Geophysical Research Letters research] 

Sediment measurements improve Tibetan Plateau water estimates 
Water stored on the Tibetan Plateau supports 2 billion people downstream and is declining due to climate change. New research quantifying sediment transport in the region finds that satellite estimates have overestimated the Tibetan Plateau’s terrestrial water decline by approximately 10%. [Geophysical Research Letters research] 

In rare opportunity, researchers observe formation of Icelandic valleys 
During the lead-up to recent volcanic eruptions near the city of Grindavík, scientists documented graben formation in real time. [Eos research spotlight] [Geophysical Research Letters research][field photos] 

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