Land-Atmosphere Interactions in Flash Drought Development

Flash droughts are characterized by the sudden onset and rapid intensification of drought conditions. Large-scale atmospheric and oceanic patterns are well-known to set the stage for drought, but land-atmosphere interactions can play an important role in exacerbating those conditions. This research seeks to understand the role of land surface feedback in flash drought development and explain how flash drought is distinguished from conventional drought through rapid intensification. These events can have substantial agricultural and economic consequences. This award will produce research that may contribute to improved forecasting of flash droughts at the subseasonal and seasonal scales. The project also includes the promotion of science literacy and training of multiple students. The overarching science question of this project is: What is the role of the land surface (soil moisture and vegetation) in modulating flash drought development in the contiguous United States? The research team hypothesizes that: 1) Atmospheric synoptic conditions play a major role in conventional droughts, but land atmosphere interactions can accelerate the drought intensification, leading to flash droughts, and 2) Impacts of land-atmosphere interactions on flash drought occur at both local and mesoscale through drought self-intensification and drought self-propagation, respectively. To address these hypotheses, the PIs plan to characterize flash droughts in the past several decades using multiple drought indicators, investigate the role of atmospheric conditions and land-surface feedback in flash drought development, evaluate flash droughts in an existing 40-year regional climate hindcast, and explore land-atmosphere interactions in new numerical modeling runs. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.