I. Atmospheric Sciences
1. Mexico City Hosts a Course on Remote Sensing for Latin Americans
Course on Remote Sensing Techniques Applied to Atmospheric Chemistry; Mexico City, Mexico, 7–11 December 2015
2. Connecting Thunderstorms and Climate Through Ozone
New data links thunderstorms to climate via their impacts on aerosols, ozone, and water vapor in the stratosphere.
3. Tropical Rainfall Intensifies While the Doldrums Narrow
Scientists show long-term changes in the Intertropical Convergence Zone's location, extent, and rainfall intensity.
II. Geology & Geophysics
1. Climate Predictions and Infectious Diseases in Southern Africa
Symposium for Science and Technology Research Partnership for Sustainable Development (SATREPS) Project 2015; Pretoria, South Africa, 12 October 2015
2. Share Your Science with Teachers and the Public at Fall Meeting
The American Geophysical Union encourages members to get involved in Exploration Station and the Geophysical Information for Teachers (GIFT) Workshop this December in San Francisco.
3. Upcoming Leadership Elections
The American Geophysical Union announces the full slate of leadership candidates. Voting will open 29 August.
III. Hazards & Disasters
1. As Lava Flows, Refined Model Predicts a Path
Simulations that melded volcano topography, satellite observations, and virtual lava accurately anticipated the destruction of villages 18 months ago by Cape Verde's Fogo volcano.
2. How Much Dissolved Mercury Is Present in Streams?
The results of a new study suggest that an improved understanding of the processes mobilizing mercury in soils will be necessary to predict water quality impacts.
IV. Ocean Sciences
1. Undersea Data Tie Slow Fault Slip to Tsunami-Causing Quakes
Slow events might help scientists better understand when and why tsunami-generating earthquakes occur.
2. Understanding the Distribution of Juvenile Jumbo Squid
An expanding zone of shallow, oxygen-depleted water in the eastern tropical Pacific Ocean may be vertically restricting the habitat of this important source of food, according to a recent study.
3. What Does the Pacific Arctic's New Normal Mean for Marine Life?
Climate change has reconfigured Arctic ecosystems. A 5-year project focuses on the relationships among oceanographic conditions and the animals and other life-forms in this region.
V. Science Policy
1. The Broken Bridge Between Geology and Museums
For lack of funding, irreplaceable collections of mineral specimens may be lost. The Earth science community must rethink the role of museums as archives and outlets for information.
2. Scientist Credibility Unhurt by Climate Advocacy, Study Suggests
In a social science experiment, a fictitious meteorologist who advocates climate policy stances retains credibility among test subjects.
VI. Climate Change
1. Gore Upbeat on Climate Stabilizing; Question Is, How Soon?
Former U.S. vice president says that responding to climate change "is the biggest business opportunity in the history of the world."
VII.Earth and Space Science
1. Imaging the Deep Sea
Due to their remoteness, deep-sea ecosystems are extremely hard to monitor. For instance, one can directly observe changes in the vegetation after a wildfire, but assessing animal community succession on hydrothermal vents is much more complicated. A good way to achieve this goal is through the analysis of time series of images.
2. More than half of streamflow in the Upper Colorado River Basin originates as groundwater
The entire Colorado River Basin currently supports 50 million people, and that amount is expected to increase by 23 million between 2000 and 2030. On average, 90 percent of streamflow in the Colorado River Basin originates in the Upper Basin, which is the area above Lees Ferry, Arizona. This water has a multitude of uses that include irrigation, municipal and industrial purposes, electric power generation, mining activities, recreation, and supporting habitat for livestock, fish and wildlife.
3. Scientists search the seas for soot
Earth system scientists from the University of California, Irvine have taken water samples from the north Pacific, north and south Atlantic, and Arctic oceans in search of repositories of black carbon, soot from burning biomass and diesel engines, among other sources. They’ve found considerably less of the material than expected, and they’ve discovered that it exists in at least two varieties, a younger pool closer to the ocean’s surface that is absorbed into the environment in a roughly 100-year cycle and an ancient reserve that remains stable for millennia.
VIII. Geophysical Research Letters
1. The Cretaceous-Paleogene boundary deposit in the Gulf of Mexico: Large-scale oceanic basin response to the Chicxulub impact
Hydrocarbon exploration in the last decade has yielded sufficient data to evaluate the Gulf of Mexico basin response to the Chicxulub asteroid impact. Given its passive marine setting and proximity to the impact structure on the Yucatán Peninsula, the gulf is the premier locale in which to study the near-field geologic effect of a bolide impact. We mapped a thick (decimeter- to hectometer-scale) deposit of carbonate debris at the Cretaceous-Paleogene boundary that is ubiquitous in the gulf and readily identifiable on borehole and seismic data. We interpret deposits seen in seismic and borehole data in the deepwater gulf to be predominately muddy debrites with minor turbidites based on cores in the southeastern gulf. Mapping of the deposit in the northern Gulf of Mexico reveals that the impact redistributed roughly 1.05 × 105 km3 of sediment therein and over 1.98 × 105 km3 gulfwide. Deposit distribution suggests that the majority of sediment derived from coastal and shallow-water environments throughout the gulf via seismic and megatsunamic processes initiated by the impact. The Texas shelf and northern margin of the Florida Platform were significant sources of sediment, while the central and southern Florida Platform underwent more localized platform collapse. The crustal structure of the ancestral gulf influenced postimpact deposition both directly and indirectly through its control on salt distribution in the Louann Salt Basin. Nevertheless, impact-generated deposition overwhelmed virtually all topography and depositional systems at the start of the Cenozoic, blanketing the gulf with carbonate debris within days.
2. Internal tides recorded at ocean bottom off the coast of Southeast Taiwan
An ocean-bottom experiment consisting of an array of four ocean-bottom seismometers (OBS) was conducted off the coast of southeast Taiwan during May-July, 2011. We develop comprehensive analyses of the space-time kinematics of the tidal signals recorded in the compact high-sensitivity temperature loggers (CHTL) and the OBS geophones at the ocean bottom with depths ranging from 1,254 – 1,610 meters. The evidence suggests that internal tides are responsible for the recorded signals: baroclinic internal waves (mainly the M2 tide) are generated by barotropic tidal currents in the Luzon Strait. The internal tides exhibit gradual phase changing and irregularly fluctuating strength, leaving signatures in the CHTL as ambient temperature variations, signifying low-mode wave motions within the stratified water layers; and in OBS geophones as intermittent “tremor” agitations, signifying high-mode turbulent flows on the seafloor. The M2 internal tides across our array are found to propagate in the northeast direction at speeds ranging from 1 to 2+ m s−1. Furthermore, the internal tides are identified at the ocean-bottom based on an operational hydrodynamic hindcast/forecast model. The simulations show good agreement with the observed temperature variation on the seafloor and substantiate the vertical velocity and displacement of the water parcel driven by the internal tides. The joint detection of the temperature and tremor signals provides further information about the interactions of internal tides with the seafloor topography and the associated energy dissipation. Our results elucidate the space-time ubiquity of the internal tides at the ocean bottom, which is an important interface of dynamic oceanography. This article is protected by copyright. All rights reserved.
IX.AUG Newsroom
1. PLUTO’S INTERACTIONS WITH THE SOLAR WIND ARE UNIQUE, STUDY FINDS
WASHINGTON, DC — Pluto has some characteristics less like that of a comet and more like much larger planets, according to an analysis of Pluto’s unique interaction with the solar wind, scientists say.
2. EXPANDING TROPICS PUSHING HIGH ALTITUDE CLOUDS TOWARDS POLES, NEW STUDY FINDS
WASHINGTON, DC — A new analysis of 30 years of satellite data suggests that a previously observed trend of high altitude clouds in the mid-latitudes shifting toward the poles is caused primarily by the expansion of the tropics.
