Evaluation of Precipitation Extremes under a Changing Climate using High Resolution Modeling Tools

Abstract: Intense and widespread storms resulting in heavy precipitation have become frequent across the U.S. in the recent past. These trends are projected to continue under enhanced radiative forcings. Heavy precipitation events have a wide variety of impacts including extensive flooding that may affect critical infrastructures such as power plants, electric grid and transportation network, making it important to quantify the changes in precipitation extremes at fine spatial resolution. To this end, this talk will focus on  1)Understanding the characteristics of precipitation extremes in a high resolution hybrid regionally downscaled ensemble of climate projections: Eleven General Circulation Models (GCMs) from CMIP5 archives are dynamically downscaled using a regional climate model to 18 km and further statistically corrected to 4 km for 40 years each in historical and future periods. The output from these simulations are evaluated to understand multiple characteristics of daily precipitation events across the U.S. 2) Evaluating probable maximum precipitation (PMP) in the southeastern U.S. under a changing climate using a numerical weather model: PMP is used as the strictest design standard for highly important energy-water infrastructures. Weather Research Forecasting model driven by reanalysis and GCM is used to downscale and maximize a total of 120 extreme storms to generate PMP estimates for historical and future periods. The simulated PMP estimates are evaluated against the conventional PMP values and the impact of changing climate on PMP estimates is examined.   

 

Bio: Deeksha Rastogi is a doctoral candidate in Energy Science and Engineering program (with a focus in Climate and Environmental Sciences), at the University of Tennessee, Knoxville. She is a researcher in the Computational Earth Sciences Group at Oak Ridge National Laboratory. Her research mainly focuses on understanding weather/climate extremes, hydroclimate and human systems responses to variations in radiative forcings. She utilizes a range of earth system modeling tools to study these responses at varying spatiotemporal scales. She holds a Master of Science degree in Atmospheric Science from University of Illinois at Urbana Champaign and a Bachelor of Technology degree from Indian School of Mines, Dhanbad, India.