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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The potential for offshore wind is expected to increase in many regions with each degree of climate warming. In Europe, offshore wind potential could increase as much as 26% if the climate warms by 4 degrees Celsius. Credit: Wikimedia commons/ Kim Hansen/ CC BY-SA 3.0

Featured Research 

Warmer climates could mean more wind power
The potential for offshore wind power generation could increase substantially under climate change, new research suggests. Researchers modeled potential wind energy increases under different temperature regimes (1.5-4 degrees Celsius) and found that potential wind energy could increase approximately 9% globally. Notably, Europe could experience a 26% increase in offshore wind power potential under 4 degrees Celsius of warming. [Geophysical Research Letters research] 

It’s just not that deep: shallow waters are very productive
Wetlands, shallow lakes and ponds have higher rates of oxygen production and consumption than larger lakes, according to a new study. Researchers sampled 26 shallow water bodies across Europe and North America and found high gross primary productivity, respiration and variable ecosystem-wide production, especially in the shallowest water bodies. [Geophysical Research Letters research] 

Cold temperatures increased COVID-19 transmission and deaths
Outbreaks of COVID-19 in several Chinese cities were amplified by cold weather, new research suggests. Cold weather increased the number of COVID-19 cases in Beijing by 28% during the winter of 2022, and could have increased the number of deaths by up to 17%. [Geophysical Research Letters research] 

More disruptive sunspots on the horizon
Solar Cycle 25 began in late 2019, marking the beginning of the Sun’s next 11-year cycle. New research using a machine learning model predicts that the Earth could receive 48% more solar shocks this cycle than it did in Solar Cycle 24, but less than in Solar Cycle 23. [Space Weather research] 

Climate change has depleted groundwater in North India 
In North India, a major agricultural area, summer monsoons have become drier and winter temperatures have warmed due to climate change. This hydrological change has led to rapid groundwater depletion (approximately 1.5 centimeters per year), and the downward trend is expected to accelerate as the climate continues to warm. [Earth’s Future research] 

Snow droughts have increased across the Pacific Northwest
Snowfall deficits, known as “snow droughts,” contribute to water shortages in summer months as more winter precipitation falls as rain instead of snow. New research finds that snow droughts increased 10-15% over the last 30 years across the Pacific Northwest, particularly in early winter. [Water Resources Research research] 

Tiny particles from explosions may help create clouds 
Large explosions can release tiny soot particles, which may then make their way into the upper atmosphere. Once there, the particles could freeze and become the first building block in the process of cloud formation, a new study finds. [JGR Atmospheres research] 

Ancient pines could reveal the heat of thousands of past seasons 
A novel 3D CT scan approach unlocks temperature records preserved in the gnarled wood of bristlecone pines. [Eos research spotlight] [Geophysical Research Letters research] 

As the river flows the colors sparkle
Diving into the science behind river color and its relationship with flow. [Eos editors’ highlights] [JGR Biogeosciences research] 

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Moss in the Arctic tundra insulates permafrost better than other groundcovers. But grass-like plants and trees are infiltrating moss territory as the climate warms, which could accelerate permafrost losses. Credit: Wikimedia commons/ Leonhard Lenz/ CC0 1.0

Featured Research
Research roundup: Stormwater and failing infrastructure
Olympic triathletes swam in Paris’ Seine River today following a $1.5 billion effort to clean up the waterway. Catch up on the latest research in stormwater system management and water pollution.
[models help build cheaper, smarter infrastructure][high tide flooding in stormwater pipes can hurt water quality][stormwater system high tide flooding likely common along the East Coast of the United States][examining stormwater “equity” versus “efficiency”][rainfall and gray infrastructure limit green infrastructure planning] 

Tundra moss losses may accelerate permafrost thaw
Mosses act as excellent insulators, slowing down the thaw of permafrost in the High Arctic by as much as eight weeks, new research finds. But mosses and small shrubs are being edged out of the tundra by a warming climate, possibly accelerating the thaw of greenhouse-gas containing permafrost. [JGR Biogeosciences research]  

Climate change will spread dengue fever-transmitting mosquitoes
As the climate warms, Aedes aegypti and albopictus mosquitoes will spread northward and westward throughout Asia, bringing deadly dengue fever with them. The study also finds that increasingly dense cities in the region will enhance the spread of disease in the future. [Earth’s Future research] 

Boston radio frequency noise mapped by bicycle
Radios, computers and cell phones all clutter up cities with radio frequency “noise,” which can impact wireless communication and surveillance systems. Researchers mapped Boston’s radio frequency landscape by towing a mobile measurement system around the city behind a bike. The resulting map shows clusters of noise around dense areas of the city, such as Back Bay and Seaport. [Radio Science research] 

Satellites find city heat islands are even hotter than expected
Urban heat islands are becoming more severe with climate change. New research finds that satellite ground temperature measurements detect hotter temperatures when compared to traditional satellite surface air measurements in New York City, with possible implications for cities worldwide. [GeoHealth research] 

Commentary: The Anthropocene is an event, not an age
The  International Union of Geological Sciences recently rejected the Anthropocene epoch as a geologic era. A new commentary argues that the Anthropocene should be considered an intensifying, ongoing event with no specific time period. [Earth’s Future research] 

Imaging below the surface reveals one of Los Angeles’ webs of faults
Damage zones extend to either side of many faults and can affect how future earthquakes behave. [Eos Research Spotlight] [AGU Advances research]

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Ships traveling near China’s coast are affecting air quality in mainland China, especially during the warmest months. Credit: Wikimedia commons/ Daniel Ramirez/ CCA BY 2.0

Featured Research
Research roundup: Record high heat
Monday, 22 July marked the hottest day ever recorded on Earth. Catch up on the latest research in extreme heat, from rising baselines to soaring maximums on land and in the sea.
[“Our hot future has arrived. Are we prepared?”][heat waves stress world’s road, rail infrastructure][Poor and nontraditionally-housed people face highest heat exposure][heatwaves increase fire, police department calls][where heat hits in the Northern Hemisphere][what we know about heat waves: a review][rising sea surface temperatures cause marine heat waves][carbon neutrality would quell increase in marine heat waves] 

Ships at sea decrease air quality in mainland China
Air pollution from offshore ships increased ozone levels in coastal Chinese cities in 2017 by up to 22%, a new study finds. The effects of the shipping emissions were amplified on more polluted days, especially during warmer months. [JGR Atmospheres research] 

Atmospheric geoengineering could increase cold-related deaths
Stratospheric aerosol injection is a geoengineering technique that injects sunlight-reflecting particles high in the atmosphere to lower surface temperatures. Stratospheric aerosol injections in Beijing in the 2060s could reduce heat-related deaths among the elderly, but also increase cold-related deaths in the city’s aging population, new research finds. Prior research from GeoHealth found that heat-related deaths will overtake cold-related deaths by the end of the century, especially among older populations. [Earth’s Future research]  

Surface water and groundwater have declined in the Indus Basin over 20 years
The Indus Basin covers over one million square kilometers in India, Pakistan, Afghanistan and China and supplies water to approximately 300 million people. Over the last 20 years, farming, human development and climate change have caused dramatic declines in both surface water and groundwater in downstream areas. In upstream areas, declines were more likely only caused by climate change. [Water Resources Research research] 

Human activities and climate change have tanked water levels in the Yangtze River
Water levels in the Yangtze River have decreased dramatically since the late 20th century. New research finds that human development, industrial activities and climate change have all contributed to runoff declines in the watersheds that surround the Upper Yangtze River. [Earth’s Future research] 

Old-growth trees are more water-savvy than younger trees
Older forests are more resilient to water shortages than younger forests, new research finds. Researchers used tree ring records and remote sensing to track old-growth and secondary-growth trees in an experimental forest in Oregon. They found that older trees stored more carbon and were more resistant to drought. [AGU Advances research] 

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Highly reflective noctilucent clouds, formed from large amounts of water vapor in the upper atmosphere, hang over Germany. New research finds that injections of water vapor into the upper atmosphere during space launches can form these icy clouds over the Arctic. Credit: Wikimedia commons/ Matthias Süßen/CC BY-SA 4.0

Featured Research

Weather “whiplash” taxes California’s water system
California relies on reservoirs and dams to generate power, fuel agriculture and feed waterways. Strong atmospheric river storms can end droughts, but rapid increases in reservoir water levels threaten dam infrastructure and reduce power generation. Future infrastructure projects should focus on creating more resilient reservoirs and recharging groundwater, according to a new study. [Water Resources Research research] 

Space launches spawn noctilucent summer clouds in the Arctic
Space traffic take-offs release large water vapor plumes. Within days, winds carry this vapor into the Arctic Circle, new research finds. In July, when the upper atmosphere is coldest, the water vapor can form noctilucent or “night shining” clouds 50 miles above the Earth. [Earth and Space Science research] 

A new look at old moon data: Apollo-era moonquakes more common than previously thought
New analysis of an archive of messy lunar quake observations, collected at Apollo landing sites between 1969 and 1977, finds that the Moon had 2.6 times more quakes during that period than previously known. The moon’s northern hemisphere was also more seismically active than its southern hemisphere, where NASA plans to land its Artemis III mission. [JGR Planets research] 

Cosmic electron beams could interfere with measurements of Europa’s ocean
Powerful electron beams discovered near Europa by the Juno spacecraft may affect the space environment surrounding the moon, which could alter how scientists measure Europa’s subsurface ocean. [Geophysical Research Letters research] 

Dim and slow meteors can still generate luminous trains
Meteors leave behind self-illuminating “trains” as they hurtle through the atmosphere. New observations of approximately 7,000 meteors reveal that meteor trains are more common than previously thought, and that slower-moving meteors leave trains just as frequently as faster-moving meteors. [JGR Space Physics research] 

Supersharp images reveal scars of major eruption on Io
Jupiter’s volcanic moon is captured in exquisite detail by an instrument atop a mountain in Arizona. [Eos research spotlight][Geophysical Research Letters research] 

Dry, cracked ground can “breathe” as environmental conditions change
Researchers used a network of fiber-optic cables to detect soil cracking in dry conditions, and found that soil cracks can expand and contract based on climate conditions. [Eos editor’s highlight][JGR Earth’s Surface research] 

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