Next Friday (September 8th) at 11:00 am EST, there will be an OCP Seminar given by Dr. Yelin Jiang, titled "Land-Atmosphere Interaction and Drought over Tropical South America." This will be a hybrid in-person/zoom seminar taking place in the Seminar Room on the 2nd Floor of the Seismology Building.
The abstract for Dr. Jiang's talk is below:
Abstract: As climate warms, drought is projected to increase in frequency and severity over most of the globe, which may have devastating impacts on agriculture, water resources, ecosystems, and the economy. Tropical South America is one of the hardest hit regions by major drought events over the past two decades. While large-scale atmospheric circulation and sea surface temperature anomalies are the primary sources of predictability for most events, land surface conditions also influence the development of these drought extremes. The goal of my research is to advance understanding of drought, its impact on the regional ecohydrological
system, and the role of land-atmosphere interaction in drought development over tropical South America. Using multiple sources of data, I first assessed the ecohydrological effects of recent meteorological droughts in tropical South America and investigated the possible mechanisms underlying the drought response and recovery of different ecohydrological systems. One interesting finding is that evapotranspiration and vegetation indices in the humid Amazonia follow an increase-then-decrease pattern during a drought, increase at the drought onset due to increased sunshine and decrease when the drought is severe enough to cause a shift from an energy-limited regime to a water-limited regime. I then conducted multiple ensembles of sensitivity experiments using both regional and global climate models to understand the role of land surface (land cover, soil temperature, and soil moisture) in regional hydroclimate variability
at multiple timescales. At the decadal-to-multidecadal timescales, I utilized a regional climate model to investigate the potential effects of historical deforestation on regional climate; at the weather-to-subseasonal timescales, I employed a global climate model to study the impacts of initial soil temperature and moisture on the development of hydrometeorological extremes. The simulated results suggested that both deforestation and anomalous soil pre-conditions (dry and/or warm soil) tend to enhance the frequency and severity of drought extremes over tropical South America.
