I. Climate Change
1.Coalition Resurrects Climate Advisory Panel Dissolved by Trump
A partnership between New York State, Columbia University, and others reestablished the panel, which will study how best to deliver climate data to state governments, cities, industries, and more.
https://eos.org/articles/coalition-resurrects-climate-advisory-panel-dissolved-by-trump
2.Study Finds First Direct Proof of Ozone Hole Recovery
Measurements show that a decline in chlorine due to the Montreal Protocol has resulted in about 20 percent less ozone depletion during the Antarctic winter than there was in 2005.
https://eos.org/scientific-press/study-finds-first-direct-proof-of-ozone-hole-recovery
3.Sea Level 2017 Conference Looks to Coastal Sea Level Rise Impact
International World Climate Research Programme/Intergovernmental Oceanographic Commission (WCRP/IOC) Open Science Conference on Regional Sea Level Rise and Its Impacts; New York, New York, 10–14 July 2017
https://eos.org/meeting-reports/sea-level-2017-conference-looks-to-coastal-sea-level-rise-impact
4.Arctic Clouds Highly Sensitive to Air Pollution
A new study finds air in the Arctic is extraordinarily sensitive to pollution and particulate matter may spur Arctic cloud formation.
https://eos.org/scientific-press/arctic-clouds-highly-sensitive-to-air-pollution
II. Hazards & Disasters
1.Working Together Toward Better Volcanic Forecasting
A National Academies report highlights challenges and opportunities in volcano science.
https://eos.org/project-updates/working-together-toward-better-volcanic-forecasting
2.Using Radar to Understand How Volcanic Eruptions Evolve
Radar satellite imagery can be used to measure constructional changes in the topography of long-lived volcanoes, according to a new study of Ecuador’s El Reventador volcano.
https://eos.org/research-spotlights/using-radar-to-understand-how-volcanic-eruptions-evolve
III. Ocean Sciences
1.Spills, Sediment, and Shoreline Contamination
A recent paper inReviews of Geophysicsdescribes the formation and behavior of oil-sediment residues in marine and coastal environments following an oil spill.
https://eos.org/editors-vox/spills-sediment-and-shoreline-contamination
IV. Biogeosciences
1.Corn’s Ancestor Could Help It Go Green
The grandfather of modern corn may hold the key to reducing its need for chemical fertilizers.
https://eos.org/articles/corns-ancestor-could-help-it-go-green
V. Geology & Geophysics
1.The Many Magmatic Modifications to the African Continent
How the very slow moving African Continent, with a lithosphere of quite varied age elements and thickness, has responded to ongoing asthenospheric modification.
https://eos.org/editor-highlights/the-many-magmatic-modifications-to-the-african-continent
2.A Window into the Emerging Anthropocene…Through Art
Want a snapshot of how humans have been changing their landscapes since the Industrial Revolution? Look at artwork at a local museum, one geoscientist says.
https://eos.org/geofizz/a-window-into-the-emerging-anthropocene-through-art
3.Melessew Nigussie Receives 2017 Africa Award for Research Excellence in Space Science
Melessew Nigussie received the 2017 Africa Award for Research Excellence in Space Science at the American Geophysical Union Fall Meeting Honors Ceremony, held on 13 December 2017 in New Orleans, La. The award honors an early-career scientist from the African continent for “completing significant work that shows the focus and promise of making outstanding contributions to research in space science.”
https://eos.org/agu-news/melessew-nigussie-receives-2017-africa-award-for-research-excellence-in-space-science
VI. Geophysical Research Letters
1. The Influence of Air-Sea Fluxes on Atmospheric Aerosols During the Summer Monsoon Over the Tropical Indian Ocean
During the summer monsoon, the western tropical Indian Ocean is predicted to be a hot spot for dimethylsulfide emissions, the major marine sulfur source to the atmosphere, and an important aerosol precursor. Other aerosol relevant fluxes, such as isoprene and sea spray, should also be enhanced, due to the steady strong winds during the monsoon. Marine air masses dominate the area during the summer monsoon, excluding the influence of continentally derived pollutants. During the SO234-2/235 cruise in the western tropical Indian Ocean from July to August 2014, directly measured eddy covariance DMS fluxes confirm that the area is a large source of sulfur to the atmosphere (cruise average 9.1 μmol m−2 d−1). The directly measured fluxes, as well as computed isoprene and sea spray fluxes, were combined with FLEXPART backward and forward trajectories to track the emissions in space and time. The fluxes show a significant positive correlation with aerosol data from the Terra and Suomi-NPP satellites, indicating a local influence of marine emissions on atmospheric aerosol numbers.
http://onlinelibrary.wiley.com/doi/10.1002/2017GL076410/full
2. Thermodynamic and Dynamic Causes of Pluvial Conditions During the Last Glacial Maximum in Western North America
During the last glacial period, precipitation minus evaporation increased across the currently arid western United States. These pluvial conditions have been commonly explained for decades by a southward deflection of the jet stream by the Laurentide Ice Sheet. Here analysis of state-of-the-art coupled climate models shows that effects of the Laurentide Ice Sheet on the mean circulation were more important than storm track changes in generating wet conditions. Namely, strong cooling by the ice sheet significantly reduced humidity over land, increasing moisture advection in the westerlies due to steepened humidity gradients. Additionally, the removal of moisture from the atmosphere by mass divergence associated with the subtropical high was diminished at the Last Glacial Maximum compared to present. These same dynamic and thermodynamic factors, working in the opposite direction, are projected to cause regional drying in western North America under increased greenhouse gas concentrations, indicating continuity from past to future in the mechanisms altering hydroclimate.
http://onlinelibrary.wiley.com/doi/10.1002/2017GL075807/full
3. The Crossover Time as an Evaluation of Ocean Models Against Persistence
A new ocean evaluation metric, the crossover time, is defined as the time it takes for a numerical model to equal the performance of persistence. As an example, the average crossover time calculated using the Lagrangian separation distance (the distance between simulated trajectories and observed drifters) for the global MERCATOR ocean model analysis is found to be about 6 days. Conversely, the model forecast has an average crossover time longer than 6 days, suggesting limited skill in Lagrangian predictability by the current generation of global ocean models. The crossover time of the velocity error is less than 3 days, which is similar to the average decorrelation time of the observed drifters. The crossover time is a useful measure to quantify future ocean model improvements.
http://onlinelibrary.wiley.com/doi/10.1002/2017GL076075/full
4. The Active Role of the Ocean in the Temporal Evolution of Climate Sensitivity
The temporal evolution of the effective climate sensitivity is shown to be influenced by the changing pattern of sea surface temperature (SST) and ocean heat uptake (OHU), which in turn have been attributed to ocean circulation changes. A set of novel experiments are performed to isolate the active role of the ocean by comparing a fully coupled CO2 quadrupling community Earth System Model (CESM) simulation against a partially coupled one, where the effect of the ocean circulation change and its impact on surface fluxes are disabled. The active OHU is responsible for the reduced effective climate sensitivity and weaker surface warming response in the fully coupled simulation. The passive OHU excites qualitatively similar feedbacks to CO2 quadrupling in a slab ocean model configuration due to the similar SST spatial pattern response in both experiments. Additionally, the nonunitary forcing efficacy of the active OHU (1.7) explains the very different net feedback parameters in the fully and partially coupled responses.
http://onlinelibrary.wiley.com/doi/10.1002/2017GL075633/full
5. Observations of Near-Surface Current Shear Help Describe Oceanic Oil and Plastic Transport
Plastics and spilled oil pose a critical threat to marine life and human health. As a result of wind forcing and wave motions, theoretical and laboratory studies predict very strong velocity variation with depth over the upper few centimeters of the water column, an observational blind spot in the real ocean. Here we present the first-ever ocean measurements of the current vector profile defined to within 1 cm of the free surface. In our illustrative example, the current magnitude averaged over the upper 1 cm of the ocean is shown to be nearly four times the average over the upper 10 m, even for mild forcing. Our findings indicate that this shear will rapidly separate pieces of marine debris which vary in size or buoyancy, making consideration of these dynamics essential to an improved understanding of the pathways along which marine plastics and oil are transported.
http://onlinelibrary.wiley.com/doi/10.1002/2017GL075891/full
VII. AGU Blogs
1.Study suggests heavy rains from tropical cyclones distort the ground below
Torrential rainfall during a tropical cyclone could be responsible for reshaping the shallow layer of Earth’s crust in the days following the storm, according to new research.
2.Study suggests heavy rains from tropical cyclones distort the ground below
Torrential rainfall during a tropical cyclone could be responsible for reshaping the shallow layer of Earth’s crust in the days following the storm, according to new research.
3.Scientists sift through lunar dirt for record of early Earth’s rocks
Hidden in the particles of moon dirt brought back by astronauts more than fifty years ago, secrets of ancient Earth lie in wait.
https://blogs.agu.org/geospace/2018/01/05/scientists-sift-lunar-dirt-record-early-earths-rocks/
4.Thoughts and Images of The Great Blizzard of 2018
Working on the Eastern Shore of Maryland, you might imagine I have been rather busy over the last few days and that is beyond an understatement. I was brought to work today in a four-wheel drive jeep and I have 11″ of snow on my sidewalk!
https://blogs.agu.org/wildwildscience/2018/01/05/thoughts-images-great-blizzard-2018/
