I.Climate Change

1.Dinosaur-Killing Asteroid Impact Made Huge Dead Zones in Oceans

The discovery reveals similarities between the extinction event that ended the Mesozoic Era and human-driven global warming.

https://eos.org/articles/dinosaur-killing-asteroid-impact-made-huge-dead-zones-in-oceans

2.Training Early-Career Polar Weather and Climate Researchers

Weather and climate are changing faster in the polar regions than anywhere else on Earth. These changes are opening up new opportunities for shipping, energy extraction, and tourism, but they also expose these sensitive regions to increasing environmental hazards and pose major challenges to local communities.

https://eos.org/meeting-reports/training-early-career-polar-weather-and-climate-researchers

3.Modeling the Effects of Geoengineering

Geoengineering (deliberate, temporary modification of the climate system; also called climate intervention or climate engineering) is increasingly receiving attention as a field of study and a potential method of reducing the most severe negative effects of climate change. If decision-makers are going to seriously consider geoengineering as an option, they need to understand the risks of deploying geoengineering, as well as the risks of not doing so.

https://eos.org/meeting-reports/modeling-the-effects-of-geoengineering

II.Hazards & Disasters

1.Forecasting the Threat from the Sun

Ensemble techniques are opening a path toward space weather forecasts that give deeper understanding of the risk posed by each solar storm that approaches our planet.

https://eos.org/editor-highlights/forecasting-the-threat-from-the-sun

2.Seismic Sensors Record a Hurricane's Roar

Newly installed infrasound sensors at a Global Seismographic Network station on Puerto Rico recorded the sounds of Hurricane Maria passing overhead.

https://eos.org/project-updates/seismic-sensors-record-a-hurricanes-roar

3.Improving Air Quality Could Prevent Thousands of Deaths in India

More than 6.1 million people worldwide die each year as a result of exposure to air pollution, which increases the risk of cardiovascular disease, lung disease, and cancer. In India, which contains many of the world’s most polluted cities, the annual death toll from air pollution exceeds 1.6 million. Now, a new study shows how implementing stricter emissions standards in India could save hundreds of thousands of lives each year.

https://eos.org/research-spotlights/improving-air-quality-could-prevent-thousands-of-deaths-in-india

III.Geology & Geophysics

1.Audio Reveals Sizes of Methane Bubbles Rising from the Seafloor

A sensitive underwater microphone captures the sounds of methane, a potent greenhouse gas, escaping into waters off the coast of Oregon. Using this sound, researchers can estimate the bubbles'sizes.

https://eos.org/articles/audio-reveals-sizes-of-methane-bubbles-rising-from-the-seafloor

IV.Biogeosciences

1.Rising Seas Increase Methane Emissions from the Mouths of Rivers

Methane is an extremely potent greenhouse gas, with more than 20 times the heat-trapping power of carbon dioxide. Produced by biological decomposition of organic matter, as well as the same processes that make fossil fuels, methane wafts from many sources, including landfills and coal deposits. Another major source is soggy wetlands full of decaying organic matter and methane-belching microbes. Now, a new study shows that as sea levels rise at an increasing rateand flood river deltas, wetlands are expanding, as is the amount of methane they contribute to the atmosphere.

https://eos.org/research-spotlights/rising-seas-increase-methane-emissions-from-the-mouths-of-rivers

V.Science Policy

1.U.S. Senate Reviews NASA's Science Priorities

The search for life, developing flagship telescopes, partnering with the private sector, and maintaining Earth science programs should be top priorities for the space agency, say witnesses.

https://eos.org/articles/u-s-senate-reviews-nasas-science-priorities

VI.Space & Planets

1.How Two Massive Space Storms Zapped Alaska

New study reveals how space weather causes rapid fluctuations in Earth's surface geomagnetic field.

https://eos.org/research-spotlights/how-two-massive-space-storms-zapped-alaska

VII.Geophysical Research Letters

1.On the relative roles of the atmosphere and ocean in the Atlantic Multi‐decadal Variability

The relative roles of the ocean and atmosphere in driving the Atlantic Multi‐decadal Variability (AMV) are investigated by isolating anomalous Sea Surface Temperature (SST) components forced by anomalous surface heat fluxes and ocean dynamics in fully‐ and partially‐coupled simulations. The impact of the ocean‐dynamics‐forced SST on air‐sea interaction is disabled in the partially‐coupled simulation in order to isolate the atmosphere‐forced variability. The atmosphere‐forced AMV component shows weak but significant variability on inter‐decadal timescales (10‐30‐yr periods), while the ocean‐forced component exhibits a strong multi‐decadal variability (25‐50‐yr periods). When coupled to the atmosphere, this ocean‐forced variability weakens and is imprinted on the coupled surface heat fluxes, which further act to damp the ocean‐forced SST variability, causing a much weaker fully‐coupled AMV. Our results suggest that the AMV is largely driven by ocean circulation variability, but its power is also affected by the strength of air‐sea coupling.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL078882

2.The role of waves, shelf slope and sediment characteristics on the development of erosional chenier plains

Cheniers are sandy ridges parallel to the coast separated by muddy deposits. Here we explore the development of erosional chenier plains, which form by winnowing during storms, through dimensional analysis and numerical results from the morphodynamic model Delft3D‐SWAN. Our results highlight that wave energy and inner‐shelf slope play an important role in the formation of erosional chenier plains. We further show that different sediment characteristics and wave climates lead to three alternative coastal landscapes: sandy strandplains, mudflats, or the more complex erosional chenier plains. Low inner‐shelf slopes are the most favorable for mudflat and chenier plain formation, while high slopes decrease the likelihood of mudflat development and preservation, favoring the formation of strandplains. The present study shows that erosional cheniers can form only when there is enough sediment availability to counteract wave action and for a specific range of shelf slopes.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL078694

3.Dome Collapse Interaction with the Atmosphere

Dome collapse is a dramatic volcanic process which dynamics evolution still presents open questions. Observational data are rare and this limits our ability to interpret the evolution of this phenomenon in terms of risk assessment. We show how the partial dome collapse of Soufrière Hills Volcano on 2010 evolved in less than 45 minutes and was characterized by five main different episode of dome failure process. Time and amplitude of seismic and infrasonic records associated with successive pyroclastic density currents show a nearly quadratic temporal trend suggesting a self‐accelerating process increasing in intensity up to the failure limit. Each episode generated gravity waves in the atmosphere, representing the first evidence of internal waves formed due to propagation of density currents in stratified fluids. Finally, we use gravity waves to estimate the total erupted mass and the plume height of the Vulcanian explosions triggered by the decompression induced by the collapse.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL078243

VIII.AGU Blogs

1.Eyewitness to the peregrine falcon's recovery

Now is not the time to see them. The evening sun is pleasantly baking us on the east side of the river, but 500-foot Tacoma Bluff, on the west side, is in the shade. Knowing they will see better in the morning light, Ambrose and Florian have tied their 24-foot Wooldridge motorboat to a spruce log for the evening.

https://blogs.agu.org/thefield/2018/08/03/eyewitness-to-the-peregrine-falcons-recovery/

2.New study predicts warming climate will drive thousands to ER for heat illness

The heat is rising. As California battles another round of wildfires, and 2018 continues toward becoming one of the hottest years on record, a new study predicts that in the coming decades the United States' heat problem will grow more dangerous and expensive.Even under the best-case scenario, the new study suggests a warming climate will drive thousands more people into emergency rooms across the country and could cost tens of millions more dollars in treatment by 2050.

https://blogs.agu.org/geospace/2018/08/07/new-study-predicts-warming-climate-will-drive-thousands-to-er-for-heat-illness/