The Interplay of Vegetation and Land-Atmosphere Feedbacks in Flash Drought Prediction

Mahmoud Osman , Benjamin Zaitchik, Patricia Lawston-Parker, Joseph Santanello, Martha Anderson

Flash droughts, known for their rapid onset and intensification, pose a significant threat to agriculture and water resources. The 2011 Texas flash drought, with its widespread agricultural losses exceeding $7.6 billion and severe ecological consequences, was a stark demonstration of their devastating impacts. This study investigates the crucial role of vegetation in numerical modeling of flash droughts, focusing on the 2011 Texas event. Utilizing the NASA Unified Weather Research and Forecasting (NU-WRF) and NASA Land Information System (LIS) modeling frameworks and the Noah Multi-Parameterization (Noah-MP) land surface model, we examine the influence of vegetation dynamics on simulating drought characteristics. By integrating satellite-derived vegetation observations and conducting controlled numerical experiments, we evaluate the model's ability to reproduce observed features of the 2011 drought. Our findings underscore the importance of vegetation representation in capturing the complex land-atmosphere feedbacks that drive the evolution of flash droughts. The incorporation of observed vegetation anomalies into the model leads to improved simulations of surface energy fluxes, atmospheric warming, and evapotranspiration patterns, particularly during the crucial onset and intensification phases of the drought. This points to the potential importance of representing vegetation variability in dynamically-based forecasts of flash drought.