I. Hydrology, Cryosphere & Earth Surface

1. A Novel Way to Map Debris Thickness on Himalayan Glaciers

By combining changes in elevation with other data, scientists have developed a method for estimating the thickness of debris covering glaciers on whose water more than 800 million people depend.

https://eos.org/research-spotlights/a-novel-way-to-map-debris-thickness-on-himalayan-glaciers

2.Climate Change May Lead to Bigger Atmospheric Rivers

New study projects atmospheric rivers will be significantly longer and wider than the ones we observe today.

https://eos.org/scientific-press/climate-change-may-lead-to-bigger-atmospheric-rivers

II. Climate Change

1. Assessing and Understanding Climate Change in Africa

Climate Change in Africa: Evidence, Mechanisms, and Impacts, Past and Present; Marrakesh, Morocco, 6–11 November 2017

https://eos.org/meeting-reports/assessing-and-understanding-climate-change-in-africa

III. Biogeosciences

1. Coastal Ocean Warming Adds to CO2 Burden

With coastal oceans around the world changing from the effects of urbanization, rising carbon dioxide levels, and climate warming, recent work begins to find new land-sea linkages.

https://eos.org/editors-vox/coastal-ocean-warming-adds-to-co2-burden

IV. Ocean Sciences

1. New Paths for Plankton in Warming Arctic?

Water flowing from the Pacific to the Atlantic could find new shortcuts, enabling plankton to survive the trip through the cold polar region.

https://eos.org/articles/new-paths-for-plankton-in-warming-arctic

V. Science Policy

1. Obama’s Science Adviser Blasts Trump Policies and Personnel

In a no-holds-barred speech, John Holdren renews call for a White House science adviser.

https://eos.org/articles/obamas-science-adviser-blasts-trump-policies-and-personnel

VI. Planetary Sciences

1. Scientists Discover an Environment on the Cusp of Habitability

A volcanically heated Costa Rican lake hosts only one type of organism, suggesting that its Mars-like environment is just barely capable of supporting life.

https://eos.org/articles/scientists-discover-an-environment-on-the-cusp-of-habitability

VII. Geophysical Research Letters

1. The Inequality of Climate Change From 1.5 to 2°C of Global Warming

The Paris Agreement aims to keep global warming well below 2°C above preindustrial levels with a preferred ambitious 1.5°C target. Developing countries, especially small island nations, pressed for the 1.5°C target to be adopted, but who will suffer the largest changes in climate if we miss this target? Here we show that exceeding the 1.5°C global warming target would lead to the poorest experiencing the greatest local climate changes. Under these circumstances greater support for climate adaptation to prevent poverty growth would be required.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL078430

2. Seismic and Geologic Evidence of Water‐Induced Earthquakes in the Three Gorges Reservoir Region of China

Earthquakes induced by reservoir impoundment pose great risk to property and lives worldwide, but studies demonstrating relationships between reservoir water levels, specific faults, and the local geology are rare. Here we show that the 2013 M 5.1 Badong earthquake, the largest earthquake so far in the Three Gorges Reservoir (TGR) region of China, occurred at a shallow depth on a right‐lateral south‐dipping strike‐slip fault. The fault is at least 15 km long and intercepts the TGR at the NS‐running Shennongxi River. We find that the earthquake and its fore‐ and aftershocks are confined to a fractured Triassic carbonate formation that crops out in the reservoir. The precise locations of earthquakes coupled with the local geology suggest that the sequence was induced by high pore pressure due to reservoir water infiltration in a specific rock type. The newly‐identified fault has the potential to generate earthquakes of magnitude approaching the designed seismic intensity limit of the Three Gorges Dam.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL077639

3. The Seismic Signature of Debris Flows: Flow Mechanics and Early Warning at Montecito, California

Debris flows are concentrated slurries of water and sediment that shape the landscape and pose a major hazard to human life and infrastructure. Seismic ground‐motion based observations promise to provide new, remote constraints on debris flow physics, but the lack of data and a theoretical basis for interpreting them hinders progress. Here we present a new mechanistic physical model for the seismic ground motion of debris flows, and apply this to the devastating debris flows in Montecito, California on January 9, 2018. The amplitude and frequency characteristics of the seismic data can distinguish debris flows from other seismic sources, and enable the estimation of debris‐flow speed, width, boulder sizes, and location. Results suggest that present instrumentation could have provided 5 minutes of early warning over limited areas, whereas a seismic array designed for debris flows would have provided 10 minutes of warning for most of the city.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL077683

4. Reconciling Atmospheric and Oceanic Views of the Transient Climate Response to Emissions

The Transient Climate Response to Emissions (TCRE), the ratio of surface warming and cumulative carbon emissions, is controlled by a product of thermal and carbon contributions. The carbon contribution involves the airborne fraction and the ratio of ocean saturated and atmospheric carbon inventories, with this ratio controlled by ocean carbonate chemistry. The evolution of the carbon contribution to the TCRE is illustrated in a hierarchy of models: a box model of the atmosphere‐ocean and an Earth system model, both integrated for 1000 years, and a suite of Earth system models integrated for 140 years. For all models, there is the same generic carbonate chemistry response: an acidifying ocean during emissions leads to a decrease in the ratio of the ocean saturated and atmospheric carbon inventories, and the carbon contribution to the TCRE. Hence, ocean carbonate chemistry is important in controlling the magnitude of the TCRE and its evolution in time.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL077849

5. Local radiative feedbacks over the Arctic based on observed short‐term climate variations

We compare various radiative feedbacks over the Arctic (60‐90°N) estimated from short‐term climate variations occurring in reanalysis, satellite, and global climate model datasets using the combined Kernel‐Gregory approach. The lapse rate and surface albedo feedbacks are positive and their magnitudes are comparable. Relative to the tropics (30°S‐30°N), the lapse rate feedback is the largest contributor to Arctic amplification among all feedbacks, followed by surface albedo feedback and Planck feedback deviation from its global mean. Both shortwave and longwave water vapor feedbacks are positive, leading to a significant positive net water vapor feedback over the Arctic. The net cloud feedback has large uncertainties including its sign, which strongly depends on the data used for all‐sky and clear‐sky radiative fluxes at the TOA, the time periods considered, and the methods used to estimate the cloud feedback.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL077852

6. The Inequality of Climate Change From 1.5 to 2°C of Global Warming

The Paris Agreement aims to keep global warming well below 2°C above preindustrial levels with a preferred ambitious 1.5°C target. Developing countries, especially small island nations, pressed for the 1.5°C target to be adopted, but who will suffer the largest changes in climate if we miss this target? Here we show that exceeding the 1.5°C global warming target would lead to the poorest experiencing the greatest local climate changes. Under these circumstances greater support for climate adaptation to prevent poverty growth would be required.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL078430

VII. AGU Blogs

1. Seismometer readings could offer debris flow early warning

Instruments designed to record earthquakes revealed information about debris-flow speed, the width of the flow and the size of boulders carried by the January 2017 mudslide in Montecito, California, and the location of the event, suggesting that the current generation of seismometers in the field could be used to provide an early warning of an incoming debris flow to residents in mudslide-prone areas.

https://blogs.agu.org/geospace/2018/05/30/seismometer-readings-could-offer-debris-flow-early-warning/

2. Increasing heat drives off clouds that dampen California wildfires

Increasing summer temperatures brought on by a combination of intensifying urbanization and warming climate are driving off once common low-lying morning clouds that shade many southern coastal areas of California, leading to increased risk of wildfires.

https://blogs.agu.org/geospace/2018/05/30/increasing-heat-drives-off-clouds-that-dampen-california-wildfires/

3. The case of the relativistic particles solved

Encircling Earth are two enormous rings — called the Van Allen radiation belts — of highly energized ions and electrons. Various processes can accelerate these particles to relativistic speeds, which endanger spacecraft unlucky enough to enter these giant bands of damaging radiation. Scientists had previously identified certain factors that might cause particles in the belts to become highly energized, but they had not known which cause dominates. Now, with new research from NASA’s Van Allen Probes and Time History of Events and Macroscale Interactions during Substorms — THEMIS — missions, published in Geophysical Research Letters, a journal of the American Geophysical Union, the verdict is in.

https://blogs.agu.org/geospace/2018/05/29/the-case-of-the-relativistic-particles-solved/

4. Webinars for scicomm: Consider me a convert

I thought webinars were basically lectures online, and don’t get me wrong, they can be. But I quickly realized that they can also be, and are, a great tool to share content and engage with audiences who normally wouldn’t be able to participate in person.

https://blogs.agu.org/sciencecommunication/2018/05/29/webinars-for-scicomm-consider-me-a-convert/

5. Another landslide at the Ituango dam site in Colombia

On 26th May 2018 a further landslide occurred at the Ituango dam site (Hidroituango) in Colombia.  The slope failure led to the evacuation of the 1500 workers at the site.  There were no injuries and the integrity of the dam does not seem to be threatened.  The best report that I can find is in El Espectador (in Spanish of course), a translated version of which is as follows.

https://blogs.agu.org/landslideblog/2018/05/28/ituango-dam-site-4/

6. Don’t Blame Mother Nature for the Devastating Flood in Ellicott City, Maryland Sunday.

Just last summer the Baltimore Sun had this story about the historic clock on Main Street in Ellicott City, Maryland. It was rededicated after the devastating “1000-year” flood of July 30,2016 that made national news. That clock was swept away this evening during the second 1000-year flood in two years in the city. Maryland Governor Larry Hogan has declared a state of emergency and rescues are still underway as I write this.

https://blogs.agu.org/wildwildscience/2018/05/28/maryland-city-devastated-by-2nd-1000-year-flood-in-two-years-dont-blame-mother-nature/