I.Climate Change

1.Just How Anomalous Is the Vast Baltic Sea Dead Zone?

Newly drilled cores from the Baltic Sea reveal 1,500 years of deoxygenation history. The record sheds light on the dire state of the Baltic Sea today.

https://eos.org/articles/just-how-anomalous-is-the-vast-baltic-sea-dead-zone

2.Scraping Bottom:Iceberg Scours Reveal North Atlantic Currents

A 3-D seismic analysis of Pleistocene iceberg gouges indicates that surface currents in the Norwegian Sea flowed northward and remained consistent during numerous glacial cycles.

https://eos.org/research-spotlights/scraping-bottom-iceberg-scours-reveal-north-atlantic-currents

3.Just How Anomalous Is the Vast Baltic Sea Dead Zone?

Newly drilled cores from the Baltic Sea reveal 1,500 years of deoxygenation history. The record sheds light on the dire state of the Baltic Sea today.

https://eos.org/articles/just-how-anomalous-is-the-vast-baltic-sea-dead-zone

4.Glaciers in East Antarctica Also Imperiled by Climate Change

Usually seen as less vulnerable, Totten and Moscow University glaciers carry the potential to add 16 feet to global sea levels.

https://eos.org/scientific-press/glaciers-in-east-antarctica-also-imperiled-by-climate-change

II.Hazards & Disasters

1.Four Ways K카lauea Is Redrawing the Map

From burying communities to building new land, this historic eruption is changing the landscape of Hawai'i Island.

https://eos.org/features/four-ways-kilauea-is-redrawing-the-map

2.At-Sea Workshop Advances Subduction Zone Research

International Ocean Discovery Program Core-Log-Seismic integration at Sea (CLSI@Sea) workshop; Nankai Trough, Philippine Sea, off the coast of southwest Japan, January–February 2018.

https://eos.org/meeting-reports/at-sea-workshop-advances-subduction-zone-research

3.Two Active Volcanoes in Japan May Share a Magma Source

Evidence collected following the 2011 eruption of Japan’s Shinmoedake volcano suggests that the powerful event affected the behavior of an active caldera nearby.

https://eos.org/articles/two-active-volcanoes-in-japan-may-share-a-magma-source

III.Science Policy

1.What Can NASA Do to Better Protect the Planets It Probes?

A new report found that decades-old policies, unclear strategies, and regulatory gaps may create future problems for the agency. Here are four ways to head off these problems.

https://eos.org/articles/what-can-nasa-do-to-better-protect-the-planets-it-probes

IV.Biogeosciences

1.The Challenges of Meeting Future Food, Energy, and Water Needs

The inherent interlinkages between food, energy, and water systems present both challenges and opportunities for a more sustainable future on Planet Earth.

https://eos.org/editors-vox/the-challenges-of-meeting-future-food-energy-and-water-needs

V.Space & Planets

1.The Kepler Revolution

The Kepler Space Telescope will soon run out of fuel and end its mission. Here are nine fundamental discoveries about planets aided by Kepler in the 9 years since its launch.

https://eos.org/features/the-kepler-revolution

2.How Jupiter's Icy Moons Got Their Bands and Grooves

Europa’s churning ice crust could reveal signs of ocean life, new study suggests.

https://eos.org/research-spotlights/how-jupiters-icy-moons-got-their-bands-and-grooves

VI.Geophysical Research Letters

1.Geothermal heat flux reveals the Iceland hotspot track underneath Greenland

Curie depths beneath Greenland are revealed by spectral analysis of data from the World Digital Magnetic Anomaly Map 2. A thermal model of the lithosphere then provides a corresponding geothermal heat flux map. This new map exhibits significantly higher frequency but lower amplitude variation than earlier heat flux maps, and provides an important boundary condition for numerical ice‐sheet models and interpretation of borehole temperature profiles. In addition, it reveals new geologically significant features. Notably, we identify a prominent quasi‐linear elevated geothermal heat flux anomaly running northwest‐southeast across Greenland. We interpret this feature to be the relic of the passage of the Iceland hotspot from 80 to 50 Ma. The expected partial melting of the lithosphere and magmatic underplating or intrusion into the lower crust is compatible with models of observed satellite gravity data and recent seismic observations. Our geological interpretation has potentially significant implications for the geodynamic evolution of Greenland.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL078289

2.Multiplex Networks: A framework for studying multi‐process multi‐scale connectivity via coupled‐network theory with an application to river deltas

Transport of water, nutrients or energy fluxes in many natural or coupled human‐natural systems occurs along different pathways that often have a wide range of transport timescales and might exchange fluxes with each other dynamically. Although network approaches have been proposed for studying connectivity and transport properties on single‐layer networks, theories considering interacting networks are lacking. We present a general framework for transport on multi‐scale coupled‐connectivity systems, via multilayer networks, which conceptualize the system as a set of interacting networks, each arranged in a separate layer, and with interactions across layers acknowledged by interlayer links. We illustrate this framework by examining transport in river deltas as a dynamic interaction of flow within river channels and overland flow in the islands, when controlled by the flooding level. We show the potential of the framework to answer quantitative questions related to the characteristic timescale of response in the system.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL078355

3.Enlarging rainfall area of tropical cyclones by atmospheric aerosols

The size of a tropical cyclone (TC), measured by the area of either rainfall or wind, is an important indicator for the potential damage by TC. Modeling studies suggested that aerosols tend to enhance rainfall in the outer rainbands, which enlarges the eyewall radius and expands the extent of rainfall area. However, no observational evidence has yet been reported. Using TC rainfall area and aerosol optical depth (AOD) data, we find that aerosols have a distinguishable footprint in the TC size. Other dynamical factors for TC size, such as relative SST and Coriolis parameter, are also quantified and discussed. We show that, on average, TC rainfall size increases 9–20 km for each 0.1 increase of AOD in the western North Pacific. This finding implies that anthropogenic aerosol pollution can increase not only TC rainfall rate, but also TC rainfall area, resulting in potentially more destructive flooding affecting larger areas.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL079427

VII.AGU Blogs

1.Alaska's big river never stops flowing

It's midsummer, a good time to slip a canoe onto the Yukon River.I start at the river town of Eagle, population 85, and will finish in Circle, population 104. Circle is about 170 twisting miles downriver. The Yukon is the longest and highest-volume river by far in Alaska. It is the third-longest in the U.S., after the Mississippi and the Missouri. At Eagle, the Yukon quietly piles into Eagle Bluff and turns northward. It is smooth, dimpled with gentle whirlpools and more than one-quarter mile wide.

https://blogs.agu.org/thefield/2018/07/27/alaskas-big-river-never-stops-flowing/

2.Alpine Glacier-BAMS State of the Climate 2017

The World Glacier Monitoring Service (WGMS)record of mass balance and terminus behavior (WGMS 2017) provides a global index for alpine glacier behavior. Glacier mass balance is the difference between accumulation and ablation, reported here in mm of water equivalence. Mean annual glacier mass balance in 2016 was −847 mm for the 37 long-term reference glaciers and −761 mm for all 140 monitored glaciers. Of the reporting reference glaciers, only one had a positive mass balance. Preliminary data reported to the WGMS in 2017 from Austria, Canada, China, France, Italy, Kazakhstan, Norway, Russia, Switzerland, and United States indicate that 2017 will be the 38th consecutive year of negative annual balances with a mean loss of −1036 mm for 29 reporting reference glaciers, with three glacier reporting a positive mass balance

https://blogs.agu.org/fromaglaciersperspective/2018/08/01/alpine-glacier-bams-state-of-the-climate-2017/