The Physics of Great Plains Drought, Its Predictability, and Its Changed Risk in a Warming World

Abstract:

The talk will examine the fundamental physics of Great Plains drought. The US Great Plains experienced a severe drought in 2012, symptoms of which included severe rainfall deficits and record setting high temperatures. An outstanding question is the relationship between the precipitation deficits and the heat wave, and further their mutual effects on soil moisture conditions. Land surface model simulations are presented to demonstrate the combined and separate effects of rainfall deficits and air temperature on soil moisture. The effects of antecedent conditions are also assessed, and implications for drought prediction are discussed. A further question to be addressed is the role of human-induced climate change on future Great Plains drought. Results are presented of the land surface responses to plausible scenarios for precipitation and temperature change. Applying an understanding of the fundamental physics of drought, we seek to better understand the sensitivity of deep soil moisture in a significantly warmer world that can inform discussions on risks for unprecedented future drought conditions in the Great Plains.