Evaluation of the impact of the tropical oscillations on the Indian summer monsoon in the global climate models

Abstract

The seasonal prediction of the Indian summer monsoon (ISM) and Monsoon Intraseasonal Oscillations (MISO), as well as the Madden Julian Oscillations (MJO) that strongly modulate MISO, is important to the country for water and crop management. We have analyzed the precipitation, convection, and cloud in the selected models from the sixth generation Coupled Model Intercomparison Projects (CMIP6). This study highlights the significant differences in simulating MISO and MJO features between the selected CMIP6 models and their possible reasons. The mean and intraseasonal features of MISO and MJO varied significantly in CMIP6 models, which may impact better depiction of convection and total cloud fraction. The probability distributions of rainfall and OLR in CMIP6 models also indicate significant variations in simulating the MISO and mean ISM. The results demonstrate the importance of cloud and convection in CMIP6 models to depict realistic MISO and MJO and provide a road map for improving ISM climate prediction and projections.