Development and Testing of Potential Indicators for the National Climate Assessment
Lead PI and Center: Rong Fu, The University of Texas at Austin
Title: Improving Assessment of Regional Climate Change in Supporting of Regional Resilience to Extreme Climate Events Over the US Southern Great Plains
Abstract:
"Flash" droughts refer to those droughts that intensify rapidly in spring and summer, coupled with strong increase of summer extreme temperatures, such as those that occurred over Texas in 2011 and the Great Plains in 2012. Climate models failed to predict these flash droughts in 2011 and 2012 and are ambiguous in projecting their future changes, largely because of models' weakness in predicting summer rainfall and soil moisture feedbacks. By contrast, climate models are more reliable in simulating changes of large-scale circulation and warming of temperatures during winter and spring seasons. Thus, we propose to develop and test a physical climate indicator of the risk of "flash" droughts in summer by using the large-scale circulation and land surface conditions in winter and spring based on observed relationships between these conditions and their underlying physical mechanisms established by previous observations and numerical model simulations.
The proposed "flash" drought indicator (IFDW) will be developed and tested using NASA Modern Era Retropsective-Analysis for Research (MERRA), North American Land Data Assimilation (NLDAS) products, the Coupled Model Inter-comparison Project Phases 5 (CMIP5) models and a suite of satellite datasets. IFDW will be mapped in a way similar to drought severity index shown at National Integrated Drought Information Center (NIDIS) with additional information about uncertainty, past and future probability distributions of IFDW.
The proposed IFDW has several advantages over the available drought indices that simply track local drought condition in past, present and future: