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AGU Research Spotlight (Jun 03-Jun 08, 2017)

2017-06-09 10:15:01

I. Science Policy & Funding

1. Trump Says United States Will Withdraw from Paris Climate Accord

Scientists and others decry the decision, arguing that it will slow efforts to address the risks of climate change.


2.Planetary Science Up, Earth Science Down in Proposed NASA Budget

The agency’s acting administrator says that the fiscal year 2018 White House budget request tells NASA to stay the course.


3. Trump Budget Would Set National Science Foundation Back a Decade

Directorate for Geosciences faces 10.7% cut.


II. Geochemistry, Mineralogy, Volcanology

1. An Autonomous Boat to Investigate Acidic Crater Lakes

A novel aquatic drone ventured into highly acidic waters to test the feasibility of remotely exploring and surveying hazardous volcanic lakes.


2. Human Activity Has Polluted European Air for 2000 Years

A new study challenges the widespread belief that environmental pollution began with the Industrial Revolution in the 1700s and 1800s.


3. “Halos” Discovered on Mars Widen Time Frame for Potential Life

Migrating silica reveals liquid water lingered longer on red planet.


III. Hazards & Disasters

1. The Asian Summer Monsoon Launches Pollutants Around the Globe

New research provides a comprehensive overview of the effect of the Asian summer monsoon (ASM) on atmospheric composition throughout the life cycle of the ASM anticyclone.


2. Proposed Federal Budget Heightens Hurricane Risk

The health, welfare, and livelihood of millions depend upon our elected officials’ continued and robust support for hurricane research.


IV. Hydrology, Cryosphere & Earth Surface

1. Seeing Soil Moisture from the Sky

A recent paper in Reviews of Geophysics describes techniques for improving the spatial resolution of satellite data on soil moisture.


2. How Variations in Earth’s Orbit Triggered the Ice Ages

Researchers pinpoint how Milankovitch cycles have driven ice growth and influenced the timing of glacial periods.


V. Planetary Sciences

1. Meet KELT-9b, the Hottest Exoplanet Ever Discovered

The exoplanet’s host star blasts it with so much radiation that it will someday evaporate.


VI. Geophysical Research Letters

1. Scanning SQUID microscopy of a ferromanganese crust from the northwestern Pacific: Submillimeter scale magnetostratigraphy as a new tool for age determination and mapping of environmental magnetic parameters

Ferromanganese crusts record long-term deep-sea environmental changes. Thus, providing their reliable high-resolution age models is important. We applied a magnetostratigraphic technique to estimate the growth rate of a ferromanganese crust using scanning SQUID (superconducting quantum interference device) microscope (SSM). SSM is designed to map the magnetic field across thin sections with submillimeter resolution. The crust sample was taken from the Takuyo-Daigo Seamount, northwestern Pacific, and recorded a limited supply of dust and sediment from continents. After drift correction and removal of spike noises, the magnetic field values were stacked within the areas of high signal-to-noise ratios. By correlating the obtained profiles with a standard geomagnetic polarity timescale, we obtained an average growth rate of 3.37 ± 0.06 mm/Ma, which is consistent with that obtained by 10Be/9Be geochronology (2.93 ± 0.15 mm/Ma). S ratio mapping shows low values after ~3 Ma, associated with voids between columnar structures.


2. Local wave activity budgets of the wintertime Northern Hemisphere: Implication for the Pacific and Atlantic storm tracks

A recently developed finite-amplitude local wave activity (LWA) diagnostic framework quantifies eddy-mean flow interaction on regional scales. Here we examine the column budgets of LWA for the winter Northern Hemisphere with the European Centre for Medium-Range Weather Forecasts ERA-Interim product, with an eye toward quantifying the maintenance and variability of the Pacific and Atlantic storm tracks. The budget is governed by (i) low-level meridional eddy heat flux, (ii) horizontal convergence of the LWA flux, and (iii) nonconservative (diabatic) sources-sinks. In both regions, the low-level meridional heat flux fuels LWA on seasonal timescales but the zonal LWA flux convergence and diabatic effects dominate the synoptic variability. Cospectral analysis shows that the interplay between barotropic zonal wind and column-averaged LWA through the meridional eddy momentum flux convergence is significant over the Pacific but not the Atlantic. A first attempt at partitioning LWA into stationary and transient eddy contributions is also discussed.


3. First report of resonant interactions between whistler mode waves in the Earth's magnetosphere

Nonlinear physics related to whistler mode waves in the Earth's magnetosphere are now becoming a hot topic. In this letter, based on Time History of Events and Macroscale Interactions during Substorms waveform data, we report several interesting whistler mode wave events, where the upper band whistler mode waves are believed to be generated through the nonlinear wave-wave coupling between two lower band waves. This is the first report on resonant interactions between whistler mode waves in the Earth's magnetosphere. In these events, the two lower band whistler mode waves are observed to have oppositely propagating directions, while the generated upper band wave has the same propagating direction as the lower band wave with the relatively higher frequency. Moreover, the wave normal angle of the excited upper band wave is usually larger than those of two lower band whistler mode waves. Our results reveal the large diversity of the evolution of whistler mode waves in the Earth's magnetosphere.


4. Scale-free distribution of Dead Sea sinkholes: Observations and modeling

There are currently more than 5500 sinkholes along the Dead Sea in Israel. These were formed due to the dissolution of subsurface salt layers as a result of the replacement of hypersaline groundwater by fresh brackish groundwater. This process has been associated with a sharp decline in the Dead Sea water level, currently more than 1 m/yr, resulting in a lower water table that has allowed the intrusion of fresher brackish water. We studied the distribution of the sinkhole sizes and found that it is scale free with a power law exponent close to 2. We constructed a stochastic cellular automata model to understand the observed scale-free behavior and the growth of the sinkhole area in time. The model consists of a lower salt layer and an upper soil layer in which cavities that develop in the lower layer lead to collapses in the upper layer. The model reproduces the observed power law distribution without involving the threshold behavior commonly associated with criticality.


5. The robustness of future changes in Northern Hemisphere blocking: A large ensemble projection with multiple sea surface temperature patterns

Future changes in the frequency of Northern Hemisphere blocking are investigated via large ensemble simulations using a 60 km mesh atmospheric general circulation model prescribed with six future sea surface temperature patterns derived from state-of-the-art climate models under a 4 K warmer climate. Our simulations depict the frequency of wintertime blocking decreasing from 16.6% ± 0.7% to 13.1% ± 2.1% in the Euro-Atlantic sector and from 17.4% ± 0.7% to 14.8% ± 2.4% in the Pacific sector. This decline in frequency is seen to affect Euro-Atlantic blocking of all durations and Pacific blocking of more than 15 days' duration. During summer, our simulations not only exhibit a robust decrease (from 10.7% ± 0.4% to 7.6% ± 0.7%) in the Euro-Atlantic blocking frequency but also show that the magnitude of this decrease is smaller for longer-lived blocking. In contrast, the Pacific blocking frequency either does not change or increases slightly, particularly for events of 15–29 days' duration.


VII. AGU Blogs

1. What caused the most toxic algal bloom ever observed in Monterey Bay?

In late spring 2015, the West Coast of North America experienced one of the most toxic algal blooms on record. A new study shows that, at least in Monterey Bay, California, the diatoms in this bloom became particularly toxic because of an unusually low ratio of silicate to nitrate in the waters of the bay.



1 June 2017 Washington, D.C. – The following statement is attributable to Chris McEntee, Executive Director and CEO of the American Geophysical Union: “When signed in December 2015, the Paris Agreement marked a historic moment. Representatives of 195 nations came together to commit to lowering greenhouse gas emissions to help slow the far-reaching effects of climate change to the nation and the world.


3. The Remarkable Things You See in Ice Cores-Like the Black Death

A new paper is out in the AGU journal GeoHealth and it shows something that is truly remarkable. Researchers looked at lead concentrations in an ice core from a glacier on the Swiss-Italy border. They wanted to know if there was a natural background of lead pollution and they pretty much got there answer.




Washington, D.C. – The following statement is attributable to Chris McEntee, Executive Director and CEO of the American Geophysical Union:

“When signed in December 2015, the Paris Agreement marked a historic moment. Representatives of 195 nations came together to commit to lowering greenhouse gas emissions to help slow the far-reaching effects of climate change to the nation and the world.



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