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Researchers from Stanford and the University of Calgary have transformed pulses of electrical current sent 1,000 feet underground into a picture of where seawater has infiltrated freshwater aquifers along the Monterey Bay coastline.

The findings, which will be published in an upcoming issue of the Journal of Hydrology but are available online now, help explain factors controlling this phenomenon, called saltwater intrusion, and could help improve the groundwater models that local water managers use to make decisions about pumping groundwater to meet drinking or farming needs.

Logging that happens today and potential future rainfall reductions in the Amazon could push the region into a vicious dieback circle. If dry seasons intensify with human-caused climate change, the risk for self-amplified forest loss would increase even more, an international team of scientists finds. If however there is a great variety of tree species in a forest patch, according to the study this can significantly strengthen the chance of survival. To detect such non-linear behavior, the researchers apply a novel complex network analysis of water fluxes.

“The Amazon rainforest is one of the tipping elements in the Earth system,” says lead-author Delphine Clara Zemp who conducted the study at the Potsdam Institute for Climate Impact Research, Germany. “We already know that on the one hand, reduced rainfall increases the risk of forest dieback, and on the other hand, forest loss can intensify regional droughts. So more droughts can lead to less forest leading to more droughts and so on. Yet the consequences of this feedback between the plants on the ground and the atmosphere above them so far was not clear. Our study provides new insight into this issue, highlighting the risk of self-amplifying forest loss which comes on top of the forest loss directly caused by the rainfall reduction.” This study results from the  German-Brazilian Research Training Group on Dynamical Phenomena in Complex Networks at (IRTG1740) hosted by Humboldt Universität zu Berlin. 

“Preventable” asthma attacks among schoolchildren cost millions in health care dollars over 10 years, according to a new study by the city of Houston, Rice University and the Houston Independent School District (HISD).

The revelation is part of a project that seeks to minimize risk to students by showing where, when and how often emergency medical crews were called to treat “uncontrolled” asthma attacks at public schools in Houston and at students’ homes.

Accurately predicting the weather - at short and long time scales - is among the most complex and important challenges faced by science. Protecting the nation’s security and economic well-being will increasingly rely on improved skill in forecasting weather, weather-driven events like floods and droughts, and long-term shifts in weather, ocean and sea-ice patterns.

As climate change continues to impact the Antarctic, glacier melt and permafrost thaw are likely to make more liquid water available to soil and aquatic ecosystems in the McMurdo Dry Valleys, potentially providing a more nutrient-rich environment for life, according to a Dartmouth study recently published in Antarctic Science. (A pdf of the study is available upon request).

With an average annual air temperature of -2.2 F and an average precipitation of 3-50 mm per year, the McMurdo Dry Valleys of Antarctica are dominated by dry soils underlain by permafrost. The Dry Valleys ecosystem is severely limited by liquid water and nutrients, resulting in limited organic matter. One such limited nutrient is phosphorus, an element that is essential to all living organisms. Understanding the spatial distribution of phosphorus in the soil is crucial to identifying where life could become more abundant in the future.