Barotropic energy conversion during Indian summer monsoon: implication of Central Indian Ocean Mode Simulation in CMIP6

The simulation and prediction of the Indian summer monsoon (ISM) its intraseasonal component in climate models remain a grand scientific challenge for numerical simulations. Recently, an mode was proposed over tropical Ocean, named central Ocean (CIO) mode. CIO index oscillations (MISO) have high correlation. In this study, simulations sixth phase Coupled Model Intercomparison Project (CMIP6) are examined. Although coupled ocean–atmosphere feedbacks associated with not fully reproduced, results show that better depiction CMIP6 is favorable northward-propagating MISO heavy rainfall during ISM. Dynamic diagnostics unveil rendition dominated by kinetic energy conversion from background to variability. Furthermore, controlled meridional shear zonal winds ( $$\frac{\partial \overline{u}}{\partial y }$$ ), which underestimated most models, leading weak barotropic instability. As result, required improving helps improve skill monsoonal precipitation.