Gaseous Earth

Paleotempestology - Given the natural and anthropogenically-induced rise in sea surface temperatures (SST), it would be helpful to know if there is a relation between SST and hurricane frequency. As a result of recent developments in microsampling, it became possible for one of my students (Amy Lehigh University Dork Sahagian - Gaseous EarthFrappier) to use speleothems (stalagmites from caves) to measure the number of hurricanes in that past, and thus establish a quantitative relationship between climate and hurricanes. The results of application of this new environmental tool throughout hurricane-prone areas can be used to predict hurricane frequency and coastal impacts in populated or otherwise sensitive areas, and thus may be a useful tool for policy, insurance companies, and coastal management.
 
El Niño and the Carbon Cycle - While investigating speleothems for paleotempestology, we discovered an unexpected relation between El Niño and carbon isotopes. Each El Niño event was reflected in a large amplitude heavy carbon isotopic excursion. This was particularly puzzling because in Belize, where the initially analyzed speleothem is from, there has been no obvious climate signal from El Niño. This means that even in areas with little other response to ENSO, speleothems can be used as a proxy for El Niño events in the geologic past. Taking the next step, we have developed a few hypotheses regarding the mechanisms through which the El Niño signal is transmitted to speleothems. These have yet to be tested on the basis of analysis of vegetation, leaf litter, soil gas, soil moisture, ground water, and drip water. 
 
Climate Change Impacts on Ecosystems - Climate change is viewed by many as being the same as global warming. However we can hardly feel the difference of a  few degrees of atmospheric temperature. It Lehigh University Dork Sahagian - Climate change impacts on ecosystemschanges more than that every day and night, and much more winter and summer. However, the hydrologic cycle, and thus ecosystems, are extremely sensitive to minute changes in temperature, atmospheric circulation, and alterations in the exchange of water, carbon, and energy between the land surface and the atmosphere. The impacts on ecosystem goods and services vary from place to place, and matter at the regional scale, so global models need to be downscales to that level for projections of regional impacts. The US, for example, can be subdivided into several regions that feel these impacts differently. On the basis of model intercomparisons using various scenarios of future anthropogenic emissions and land use, regional projections can be made, and the difference between them indicate that global models are not, by themselves, sufficient for land use planning or resource management. It turns out that at the regional scale, dry places get drier, and wet places get wetter, but there are important differences in seasonality. As we improve our ability to resolve regional climate change impacts, it will be possible to more reliably reduce vulnerability to climate change impacts and maximize the provision of ecosystem goods and services.

© IMRC CAS 2016

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