Evaluating high-resolution regional earth system model for the representation of hydro-climatic variables and drought over India

Drought is a hydro-climatic extreme disaster that substantially impacts society and the economy to a great extent. Due to the different processes involved in drought evolution, understanding the drought variability and propagation based on a particular driver may cause uncertainty. Therefore, in this study, a comparative assessment of hydro-climatic variables and drought is done using a high resolution regional earth system model (RESM). This RESM is simulated over the CORDEX South-Asian domain with a focus to understand Indian drought dynamics. Interestingly, the results of RESM improved the representation of present climate followed by RCM and least by GCM. The mean climatology of precipitation and temperature has significant improvement, which signifies that the model has good skills to simulate the regional climate, especially monsoon. In addition, other hydro-climatic variables like runoff, soil-moisture also has a better representation of the regional pattern. The biases are noticed over a few regions though the correlation is statistically significant over most regions. The drought representation by associated indices is well captured with a strong correlation among indices, though uncertainty also noticed. This highly validated RESM may provide better inputs for assessing future drought under warming climate scenarios which will be discussed in brief at the conference. Acknowledgement: We are thankful for funding from Department of Science and Technology (DST), Govt. of India, Grant number DST/IMT/RUS/RSF/P-33/G and Russian Science Foundation (Project No. 19-47-02015). The first author is also thankful to the Department of Science and Technology (DST), Govt. of India for providing DST INSPIRE fellowship (Grant No. IF160281).