1/31/2024: Densest lightning on Earth occurs over sea, not land

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Dark thunderclouds are lit from within by lightning over a flat grey ocean.

Lightning off the coast of Cancun, Mexico. The largest thunderstorms, flaunting the biggest lightning megaflashes, frequent the Great Plains in North America and the eastern La Plata basin in South America, but the storms with the highest density of flashes occur over the ocean, mostly through the Gulf of Mexico and east of South Africa, a new study finds.
Credit: Keith Pomakis, CC BY-SA 2.5

AGU News

Press registration open for Ocean Sciences Meeting
Browse nearly 5,000 abstracts for #OSM24, held 18-23 February in New Orleans. [OSM24 scientific program][OSM24 press registration][press release]

Register to attend the Triennial Earth-Sun Summit during the eclipse!
The Triennial Earth-Sun Summit (TESS) will be held 7-12 April in Dallas, Texas, in the path of totality. Scientific programming begins on 9 April, the day after the eclipse. To register, simply email us at [email protected]. Scientific sessions are on-site only. AGU’s housing is full. [TESS website][scientific program]

Featured Research

Small farm irrigation ponds have big evaporative losses in Europe’s water-stressed regions
In Italy, Spain and Portugal, the number of reservoirs smaller than 100 square meters have doubled in the last two decades. Hotter temperatures are driving both rising demand for stored irrigation water and increasing losses to evaporation, according to a study that finds nearly 40% of the water capacity in the ponds evaporates. [Earth’s Future research]

Densest lightning on Earth occurs over sea, not land
A new class of extreme thunderstorm claims the title for most frequent lightning concentrated in a small area — some flashing so fast they would appear continuously lit to the human eye. These compact “lightning-dense” storms were previously underappreciated because their lightning flashes in a tempo too quick for accurate measurement by automated detection systems. Strong updrafts rivaling the most powerful thunderstorms on Earth drive the high flash rate, but unlike the largest thunderstorms, they occur over the ocean. [Earth and Space Science research]

13,000 barriers fragment Mekong Rivers’ rich habitat
The Mekong River basin in Southeast Asia is one of the most biodiverse regions on the planet, but dams and other waterway barriers can cause ecologically damaging habitat fragmentation. A new study finds more than 10,000 previously undocumented such barriers, suggesting a greater degree of habitat fragmentation than known. [Water Resources Research research]

Measuring methane stemming from tree stems
Wetland tree stem emissions have emerged as a significant contributor to the global methane budget. A new study tracks how they vary by season, location, and hydrological conditions. [Journal of Geophysical Research: Biogeosciences research] [Eos research spotlight]

Deep learning tackles deep uncertainty about future sea levels
A new method based on artificial intelligence could help accelerate projections of polar ice melt and future sea level rise. [Journal of Advances in Modeling Earth Systems research] [Eos editors’ highlight]

A dust-up over dust underestimations
Dust has significant impacts on the environment, climate, air quality, and human health, yet dust events are underestimated and therefore do not receive the level of attention necessary. [GeoHealth research][Eos editors’ highlight]

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AGU (www.agu.org) is a global community supporting more than half a million advocates and professionals in Earth and space sciences. Through broad and inclusive partnerships, AGU aims to advance discovery and solution science that accelerate knowledge and create solutions that are ethical, unbiased and respectful of communities and their values. Our programs include serving as a scholarly publisher, convening virtual and in-person events and providing career support. We live our values in everything we do, such as our net zero energy renovated building in Washington, D.C. and our Ethics and Equity Center, which fosters a diverse and inclusive geoscience community to ensure responsible conduct.

1/17/2024: What we don’t know about drinking water contamination

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Close-up view of hands surrounding a pine tree seedling freshly planted in wood mulch.

Caption: Forests are big carbon sinks, but not big enough to mitigate the effects of continuing high carbon emissions, researchers report in JGR Biogeosciences.
Credit: Pacific Southwest Forest Service USDA

AGU News

Nominate yourself or a colleague for AGU’s 2024 Journalism Awards
Awards for news and feature writing honor outstanding reporting in the Earth and space sciences published in the previous year (2023). Self-nominations are encouraged. The deadline is 27 March 2024 at 11:59 p.m. ET. [press release]

Book housing for the Ocean Sciences Meeting by 24 January
Browse nearly 5,000 abstracts for #OSM24, held 18-23 February in New Orleans, and register with housing before the housing deadline on 24 January. [OSM24 scientific program][OSM24 press registration][press release]

Featured Research

Drying, not just dry weather, will dry out central US
Climate change will bring water shortages to many parts of the United States, but today’s least rainy regions are not always the most at risk. Heat-driven evaporation from soil and plants may be a bigger future problem than lack of rain for northern Midwest states, according to a new analysis of water vulnerability and its sources across the contiguous states under high and low carbon emissions. [Geophysical Research Letters research]

Known unknowns and unknown unknowns of drinking water contamination
A review explores the state of the science on “contaminants of emerging concern,” an ever-expanding class of potential chemical and biological hazards, and how future changes in weather, population and demographics could complicate the availability of potable water. [GeoHealth review]

Forestation is not enough to cool the planet
Growing trees can bank a lot of carbon, but not enough to significantly mitigate global warming through carbon dioxide removal if carbon emissions remain high. [JGR Biogeosciences research]

How heat rises through Europa’s ocean
A new study examines how heat may be transferred from the mantle, through the ocean, and into the icy crust of Europa, one of Jupiter’s moons — perhaps among the most promising places in our solar system to search for life. [Eos research spotlight][AGU Advances research]

Glaciers rise and fall — and melt — with tides
The effect of ocean water creeping beneath Greenland ice is stronger than scientists realized. [Eos research spotlight][Geophysical Research Letters research]

Plants reveal the history of Earth’s largest tropical ice cap
Rooted plants buried by advancing outlet glaciers illustrate rapid changes in the extent of Quelccaya Ice Cap in Peru during the Holocene. [Eos editors’ highlight][JGR Earth Surface research]

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AGU (www.agu.org) is a global community supporting more than half a million advocates and professionals in Earth and space sciences. Through broad and inclusive partnerships, AGU aims to advance discovery and solution science that accelerate knowledge and create solutions that are ethical, unbiased and respectful of communities and their values. Our programs include serving as a scholarly publisher, convening virtual and in-person events and providing career support. We live our values in everything we do, such as our net zero energy renovated building in Washington, D.C. and our Ethics and Equity Center, which fosters a diverse and inclusive geoscience community to ensure responsible

01/03/2024: 34% loss of Alps’ ice inevitable by 2050

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Frozen river of a the Aletsch Glacier curves in the forground. The peaks of Jungfrau, Monch and Trogberg are in the background against a blue sky.

Grosser Aletschgletscher, the largest glacier in the Alps at 23 kilometers (14 miles) will lose 34% of its 15.4 cubic kilometers of ice by 2050, according to a new study in Geophysical Research Letters.
Credit: Dirk Beyer CC BY-SA 2.5

Ocean Sciences Meeting 2024 coming soon
The scientific program for #OSM24, held 18-23 February in New Orleans, is now available online. Browse nearly 5,000 abstracts on all things ocean science and register today! [OSM24 scientific program][OSM24 press registration]

AGU23 posters and recordings available through February
AGU’s 2023 annual meeting brought 24,500 Earth and space science experts to San Francisco and an additional 2,500 online participants. Recordings of scientific sessions will remain available to registered attendees on the online conference platform through the end of February. [AGU23 press event recordings][online conference platform][AGU23 advisories and press releases]

Featured Research

Erosion by flowing lava erased Moon’s missing craters
Distinctive dark plains called maria on the Moon’s ever-Earth-facing nearside are the result of ancient volcanic activity triggered by asteroid impacts on the opposite far side. These lowlands are smoother than expected. Impacts smaller than 90 kilometers wide are less common in nearside basins than in the farside highlands, even when scientist look for evidence of crater rings buried under the surface, suggesting the intense heat of lengthy mare flows 3.6 million years ago melted away the older topography. [JGR Planets research]

In the Alps, at least 34% ice loss is inevitable by 2050
Under current climate conditions, glaciers in the Alps will lose, at a minimum, 34% of their 2020 ice volume in the next quarter century regardless of future warming, according to a new study that incorporates advances in 3D modeling of ice dynamics. [Geophysical Research Letters research]

Carbon lost to winter warming in permafrost regions could cost trillions
Permafrost underlays 22% of land in the Northern Hemisphere, impounding about twice as much carbon as Earth’s atmosphere. This vast carbon sink will shrink as warming melts the ice and microbial decomposition releases stored carbon. The economic costs of becoming a carbon source will outweigh expected growth of GDP, a new analysis finds, and this flip could occur as early as 2057 if current emissions are not curtailed. [Global Biogeochemical Cycles research]

Arctic Ocean absorbs more carbon dioxide as sea ice retreats
The Arctic Ocean has been a net sink for carbon dioxide in the atmosphere from 1985 to 2018. Unlike the global ocean, the carbon uptake Arctic has almost kept pace with rising carbon dioxide in the atmosphere over this time period. The shrinking barrier of the sea ice cover has been the most important driver of this acceleration in recent years. [Global Biogeochemical Cycles research]

Ice clouds possible on Venus
Famously hot Venus is cold enough at the top of the atmospheric layer called the mesosphere to form ice clouds of water and carbon dioxide. A new study proposes a 10-kilometer-thick, invisible water ice cloud veil persists 120 kilometers above the surface. Short-lived dry ice clouds have not been observed but could be important “cold-traps” for water, preventing it from being lost to space. [JGR Planets research]

8/23/2023: Lead in urban soils disproportionately harms Black Americans

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A map of the city of New Orleans showing the milligrams of lead per kilogram of soil. Green is low and red is high.

As in many traffic-congested cities, lead has built up in the soil of inner city New Orleans, La.
Credit: Laidlaw et al, GeoHealth https://doi.org/10.1029/2023GH000829

Featured research

Toxic lead in urban soils harms Black Americans
Urban populations, and particularly majority Black communities, have elevated concentrations of lead in their blood. Previous studies assume that today’s atmospheric lead concentrations are caused by current lead emissions; however, new research finds that urban soils contain lead from the 20th century that becomes airborne during dry seasons, harming vulnerable communities. [GeoHealth commentary]

Extreme heatwaves in China will occur every 8 years by 2100
In 2022, China experienced two record-breaking heatwaves that historically have a return period of tens of thousands of years. As temperatures rise, heatwaves of this intensity are projected to occur every 8.5 years on average by the end of the century. Researchers call for adaptation planners to consider new efforts to build social resilience to extreme heatwaves. [Geophysical Research Letters research].

Tree leaves point to valuable ores underground
Valuable ores are found in bedrock but are often covered by soil and vegetation. Plants growing on top of ores take in elements from soil, which contains broken-down bedrock. A new study demonstrates subtle changes in the light reflected from leaves can mark the presence of copper and molybdenum hidden below. [Radio Science research]

Effects of harvest, wildfires and grazing on carbon in US forests
U.S. forests have been recovering from past depletion since the early 20th century, but fire, harvest and grazing have contributed to continued forest loss. Tree harvest is the key driver in forest biomass loss, with wildfire also contributing. In total, U.S. forest recovery has led to a net increase in carbon stock density of nearly 40%. [Global Biogeochemical Cycles research]

Extreme precipitation storms will shrink in tropics but expand over arid regions
Rising temperatures will cause more concentrated and intense precipitation events in the tropics, and larger rainstorms in arid regions and central Europe. These short-duration storms can lead to severe flash flooding, creating a need for effective stormwater systems in urban areas. [Geophysical Research Letters research]

Beavers are remaking microbial ecosystems in the Arctic
As beavers expand their range northward into the Arctic tundra, changes in bacterial, archaeal and fungal communities appear to be following. The increasingly plant rich environments will likely capture more carbon, helping to mitigate carbon emissions from the environment, but in the long run, those gains may be offset by carbon released as microbes break down the vegetation. [JGR Biogeosciences research] [Eos research spotlight]

7/19/2023: Mars’ ancient lakes point to past warm spells

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Featured video 
The Türkiye-Syria double earthquake: what happened underground
Earlier this year, a succession of powerful earthquakes devastated vulnerable communities along the Türkiye-Syria border. A new study used seismic records from around the world to estimate how the earthquakes evolved and found that the two massive quakes displayed an irregular rupture evolution.[Geophysical Research Letters research]

Featured research 
Mars crater once hosted large lakes and rivers
Mars is currently a desert, but a recent study found that the planet’s Antoniadi crater intermittently hosted the planet’s largest thriving river and lake systems  3.7 to 2.4 billion years ago — on par with Earth’s largest lakes. This supports the idea that Mars’ early climate was punctuated with episodes of warmth and provides a compelling site for studying Mars’ potential past habitability. [JGR Planets research]
 

Tropical cyclones increase in China’s most vulnerable regions
From 2011 to 2020, the number of areas impacted by tropical cyclones expanded significantly more than they did from 2001 to 2010. In particular, tropical cyclones increased in Northeast China where populations have a lower capacity to prevent and mitigate disasters. [Earth and Space Science research]
 

Climate change and human behavior threaten Brazil’s water security
A recent study assessed more than 700 catchments in Brazil and found that 81% of them will likely experience water insecurity by 2100 because of rising temperatures, and more than half of the catchments could experience extreme water insecurity due to an expected increase in human water use. [Water Resources Research research]
 

Thawing permafrost will likely accelerate the erosion of large rivers 
Permafrost reduces riverbank erosion by up to nine times compared to rivers in warmer regions by slowing the release of carbon and sediments. A new study finds that as rising temperatures thaw arctic permafrost, larger riverbanks could undergo rapid erosion but impacts on smaller rivers will be minimal. [JGR Earth Surface research]
 

Sedimentary layers can be complex clocks
Layers of sedimentary rock are often studied to recreate Earth’s history. But rocks aren’t always the most reliable historians. New research models how environmental conditions can affect how quickly sediment accumulates, which can complicate the issue for scientists who are trying to estimate the lengths of time periods in Earth’s past. [Geophysical Research Letters research] [Eos research spotlight] 

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AGU (www.agu.org) is a global community supporting more than half a million advocates and professionals in Earth and space sciences. Through broad and inclusive partnerships, AGU aims to advance discovery and solution science that accelerate knowledge and create solutions that are ethical, unbiased and respectful of communities and their values. Our programs include serving as a scholarly publisher, convening virtual and in-person events and providing career support. We live our values in everything we do, such as our net zero energy renovated building in Washington, D.C. and our Ethics and Equity Center, which fosters a diverse and inclusive geoscience community to ensure responsible conduct