A selection of new AGU research updated weekly.
9 September 2020
Io’s lava layers rise in sudden hot eruptions
Different melting rates of rock can explain highest temperature eruptions on Jupiter’s volcanic moon. [research paper]
SwRI-led study indicates sand-sized meteoroids are peppering asteroid Bennu
Comet fragments litter space near the sun. A new study suggests head-on collisions with this space sand, striking with the force of a shotgun blast, explains the regular ejections of tiny rocks from Bennu’s surface observed by visiting OSIRIS-REX spacecraft as the near-Earth asteroid approaches the Sun. [SwRI press release] [research paper]
Frequent river capture drives biological innovation
A new model examines the rate at which new aquatic species emerge when once independent rivers are rerouted to merge with neighboring channels. [research paper]
A machine-learning assist to predicting hurricane intensity
An experimental computer model promises to greatly improve the accuracy of detecting rapid-intensification events. [JPL press release] [research paper]
26 August 2020
Europa’s icy shell rotated 70 degrees in the last few million years
Europa’s poles are not where they used to be, according to a new study in Geophysical Research Letters. Cracks in the surface of Jupiter’s icy moon indicate its shell of ice rotated by 70 degrees sometime in the last several million years, adding support to prior evidence for a subsurface ocean. [USRA press release] [research paper]
Lightning probably doesn’t exist on Saturn’s moon Titan
A new study of data collected by the Cassini spacecraft during 126 flyby’s of Saturn’s largest moon in the Journal of Geophysical Research: Planets found no radio signals that could be attributed to Titan lightning. The long observation times make it very likely that Titan lightning does not exist, is very weak, or is very rare. [research paper]
Heat stress triggers summer flood events in the Midwest
In storm-prone Midwestern states like Iowa, Illinois and Indiana, flooding is more likely to occur after periods of high heat and humidity, according to a new study Geophysical Research Letters that is the first to establish a connection between these two potentially dangerous weather events. [research paper]
February lockdown in China caused a drop in some types of air pollution, but not others
A new study in Geophysical Research Letters analyzed how the February near-total shutdown of mobility affected the air over China. Results show a striking drop in nitrogen oxides, a gas that comes mainly from tailpipes and is one component of smog. [University of Washington press release] [research paper]
19 August 2020
Hedging for privacy in smart water meters
A new study demonstrates how “privacy friendly” smart water metering technology could be implemented in real‐life systems and reduce the privacy concerns of water consumers. [research paper]
Rise of Great Lakes surface water, sinking of the upper Midwest of the United States, and viscous collapse of the forebulge of the former Laurentide ice sheet
Great Lakes water levels rose 0.7–1.5 m from 2013 to 2019 and the Great Lakes floor fell 8–23 mm during the same time period as a result of Earth’s crust adjusting to retreat of the Laurentide Ice Sheet. [research paper]
Equatorial winds ripple down to Antarctica
Researchers have uncovered a critical connection between winds at Earth’s equator and atmospheric waves 6,000 miles away at the South Pole. The team has found, for the first time, evidence of an atmospheric circulation pattern that originates at the equator at McMurdo, Antarctica. [CIRES press release] [research paper]
Evergreen needle magnetization as a proxy for particulate matter pollution in urban environments
Magnetic measurements of evergreen needles can be used as a proxy for particulate matter pollution in Salt Lake City, Utah, showing needle magnetization is a fast, cost‐effective way to measure pollution in urban environments year-round. [research paper]
12 August 2020
NASA’s MAVEN observes Martian night sky pulsing in ultraviolet light (video)
Vast areas of the Martian night sky pulse in ultraviolet light, according to images from NASA’s MAVEN spacecraft. The results are being used to illuminate complex circulation patterns in the Martian atmosphere. [NASA press release] [research paper] [video]
New water-ice deposits found on Mars
A new study in Geophysical Research Letters reports new water-ice deposits in the midlatitude region of Mars a few meters below the surface, exposed in crater walls, and provides evidence that snow possibly accumulated within the last 25 to hundred million years. [research paper]
Human-generated seismic noise quiets during quarantine
A seismic station within Rio de Janeiro city showed a drastic reduction of seismic noise, which is mainly caused by traffic, after isolation measures imposed by the state government and city council to slow the spread of COVID-19, researchers report in Geophysical Research Letters. [research paper]
A warming California sets the stage for future floods
By the 2070s, global warming will increase extreme rainfall and reduce snowfall in the Sierra Nevada, delivering a double whammy that will likely overwhelm California’s reservoirs and heighten the risk of flooding in much of the state, according to a new study in Geophysical Research Letters. [UCLA press release] [research paper]
Wind farms reduce accuracy of rainfall forecasts
Wind farms corrupt radar‐rainfall estimates used for flood forecasting for small communities where wind farms occupy a large portion of the upstream basins. [research paper]
Satellites measure desert raindrops
Global rainfall mapping is a very challenging task because ground‐based observations from radars or rain‐gauges are limited or unavailable over many regions, particularly deserts. A new study in Geophysical Research Letters demonstrates a new method to measure desert rain using satellite observations. [research paper]
5 August 2020
Air pollution from the 2019 Amazon fires killed nearly 5,000 people
Despite high biomass burning emissions in Brazil and the international attention drawn by the relaxation of Amazon protections in 2019, little is known about the health impacts on Brazilians from breathing fine particulates (PM2.5) produced by the fires. A new study in GeoHealth attributes an estimated 4,966 premature deaths to fire emissions in 2019, an increase of 74% over the previous year. [research paper]
Mine waste piles in northeast Oklahoma are a source of airborne lead
A new study in GeoHealth shows a correlation between piles of mine waste called chat and airborne lead contamination in the ex-mining ghost town of Picher, Oklahoma, along with nearby Shawnee Lake. The authors calculated that Picher has two to five times more airborne lead than the city of Tulsa, despite being an abandoned ghost town since 2010. [research paper]
Climate impacts on China’s agricultural production will cost 17.8% of total GDP by 2100
A new study in Earth’s Future calculates although the direct damage to China’s agricultural sector from climate change is equivalent to only 1% of gross domestic product by the end of the century, cascading effects will be 18 times larger. [research paper]
How the seafloor of the Antarctic Ocean is changing – and the climate is following suit
How did the ice masses of the southern continent react to climate changes in the past, and how will they in the future? A new study in Geochemistry, Geophysics, Geosystems reconstructed the depth of the Southern Ocean during nine pivotal intervals over 34 million years. The new seafloor maps show the large ice sheets of East Antarctica reacted to climate change in a similar way during past warm phases to how ice sheets in West Antarctica are doing so today. [Alfred-Wegener-Institut press release] [research paper]
29 July 2020
Réunion’s largest-ever dengue outbreak could have been predicted in advance
A new study in GeoHealth links unseasonably high temperatures and heavy rainfall to an unprecedented 2018 dengue outbreak on the French overseas department of Réunion, a small island in the Indian Ocean east of Madagascar. The outbreak, which infected over 6,000 people and represented a 6,000% increase in dengue cases over the preceding year, could have been predicted weeks in advance, according to the study findings. [Research paper]
In the tropical Pacific, acidification comes from below
A new study in Global Biogeochemical Cycles found the rate of acidification in the western tropical Pacific Warm Pool was 20% slower than expected based on the rate of increase of carbon dioxide in the atmosphere and local exchange with the air above the ocean. [Research paper]
Climate change is making the surface of the Arctic Ocean less salty
Unexplained influx of surface fresh water in the Arctic Ocean in the past two decades is likely driven by climate change, not natural variability, according to a new study in Geophysical Research Letters. [Research paper]
Warming peatlands will become carbon sources
In wet, cold, and acidic conditions, northern bogs and fens capture carbon in peat. Heat speeds decomposition, which releases greenhouse gasses carbon dioxide and methane. A new study in AGU Advances experimentally warmed patches of Minnesota peat bog, changing them from carbon storage to carbon emitters. [Research paper]
22 July 2020
An assessment of Earth’s climate sensitivity using multiple lines of evidence
Earth’s climate sensitivity is a fundamental quantitative measure of the susceptibility of Earth’s climate to human influence. A landmark report in 1979 concluded that it probably lies between 1.5‐4.5°C per doubling of atmospheric carbon dioxide. A new study in Reviews of Geophysics reassesses this estimate and finds a large volume of consistent evidence now points to a climate sensitivity near the middle or upper part of this range. It now appears extremely unlikely that climate sensitivity could be low enough to avoid substantial climate change (well in excess of 2°C warming) under a high‐emissions future scenario.
Who wants to count all the craters on Mars? Not me!
Humans found hundreds of thousands of craters on Mars greater than 1 kilometer in diameter, but now computers automate the process delivering crater counts as well as geologically meaningful ages.
Citizen science reduces risks from combusting coal-mine wastes
A community-based citizen science study on spontaneously combusting coal-mine waste heaps in Myanmar underpins the development of risk management plans to protect individuals and communities.
Estuary research suffers from scientific bias
Researchers are calling for a closer look at nutrient cycling in tropical and low-nutrient estuaries, which have long been overlooked in the scientific literature.
Modeling water stress for shared water resources
Billions of people rely on water resources that originate across borders. New research evaluates how climate change and increased water demand could affect future water stress.
What controlled the growth of the Southern Central Andes?
Flat-slab subduction appears to have played a minor role in the growth of the Southern Central Andes, with evidence for eastward migrating deformation.
Global modeling of seasonal mortality rates from river floods
River floods affect millions of people and kill thousands each year. Knowing the average timing and magnitude of floods can help to better prepare for such disasters. A new study in Earth’s Future presents a physically-based modelling framework to estimate population exposure and mortality rates from river floods in all the world countries, as well as their temporal distribution within the average year.
15 July 2020
Early-warning signals for critical temperature transitions
A new statistical method could help meteorologists predict heat waves days-to-weeks in advance, augmenting more complicated, existing meteorological models according to a new study in Geophysical Research Letters. The study identified distinctive patterns of change in two types of statistical analysis of temperature data that preceded heat waves or longer periods of climate warming. The statistical signatures reflect perturbation in temperature that accumulates until it hits a critical threshold or state change. Read the Arizona State University press release.
An analysis of the Trouvelot’s auroral drawing on 1/2 March 1872: Plausible evidence for recurrent geomagnetic storms
Étienne Trouvelot’s drawings of the great aurora has been often cited as a remarkable example of a mid‐latitude aurora, but scientists have been puzzled by other evidence that 1 March 1872 was a geomagnetically quiet day. A new study in the Journal of Geophysical Research: Space Physics finds the artist probably got the date right and may have recorded an overlooked storm causes by recurring solar activity.
Novel quantification of shallow sediment compaction by GPS interferometric reflectometry and implications for flood susceptibility
A new study in Geophysical Research Letters finds the rate of vertical land motion from shallow compaction is comparable to or larger than the rate of sea‐level rise in the Mississippi Delta and on the eastern margin of the North Sea because of lost sediment inputs. Estimates of future flood risk and land loss for many of the world’s great coastal cities built on river deltas may be too low.
Unprecedented drought challenges for Texas water resources in a changing climate: what do researchers and stakeholders need to know?
Texans need to prepare for a near future that is hotter, drier and fraught with more water extremes, according to a new study in Earth’s Future. But preparation isn’t a one-size-fits-all solution, especially in the face of megadroughts that could be unlike anything the state has seen in the past thousand years. Read the University of Texas press release.
8 July 2020:
The silver lining of COVID‐19: estimation of short‐term health impacts due to lockdown in the Yangtze River Delta region, China
A new study in GeoHealth tackles the question of what short‐term health impacts are associated with improved air quality during COVID-19 lockdowns in China.
Estimating Arctic temperature impacts from select European residential heating appliances and mitigation strategies
Using data from 14 European countries, a new study in Earth’s Future estimates air quality and Arctic climate impacts based on black carbon, organic carbon, and sulfate emissions from 6 different wood‐fueled home heating appliances.
The disappearing lake: An historical analysis of drought and the Salton Sea in the context of the GeoHealth framework
A new study in GeoHealth finds future droughts and heatwaves are expected to rise in frequency and severity in California’s Imperial Valley region and may disproportionately affect those impacted by financial and health disparities.
1 July 2020:
Disproving the Bodélé depression as the primary source of dust fertilizing the Amazon Rainforest
Scientists have believed an ancient dry lake bed in Chad called the Bodélé depression is the main source of the more than 200 million tons of dust from the Sahara, North Africa, that blows across the Atlantic, because Bodélé is the biggest source of dust in the world. But geochemical analysis of soil in the Amazon indicates the old lakebed isn’t a good match. A new study in Geophysical Research Letters contends El Djouf, a desert on the border of Mali and Mauritania, 2,600 kilometers (1,600 miles) to the west, more likely contributes the bulk of the dust. The source is important for the accuracy of models calculating the contribution of the dust to the productivity of the Amazon.
Associations between dust storms and intensive care unit admissions in the United States, 2000‐2015
Human-driven climate change is affecting dust storm occurrences and human exposure to dust particles in the United States. Studies worldwide have found negative health consequences related to dust exposure resulting in increased emergency department visits and hospitalizations. A new study in GeoHealth finds a 4.8% increase in intensive care admissions during dust storms. Five days after storms, admissions for respiratory illness remained 7.5% higher than usual.
Antarctic ozone enhancement during the 2019 sudden stratospheric warming event
In August and September of 2019, the ozone hole over Earth’s southern pole was the smallest ever recorded since its discovery. A new paper in the Geophysical Research Letters details how a warm three weeks in the stratosphere 20-30 kilometers above Antarctica prevented formation of the usual icy clouds that trap ozone-damaging chemicals.
New WMO certified megaflash lightning extremes for flash distance (709 km) and duration (16.73 seconds) recorded from space
A new study in Geophysical Research Letters established two new world records for the longest reported distance and the longest reported duration for single lightning flashes in, respectively, Brazil and Argentina. The new records for “megaflashes”, verified with new satellite lightning imagery technology, more than double the previous values measured. Read the World Meteorological Organization press release.