Abstract
<title>Abstract</title> <p>This study evaluates the capability of CMIP5 and CMIP6 models in simulating Indian Summer Monsoon Rainfall (ISMR) during 1975 to 2005 and examines their representation of sea surface temperature (SST) teleconnections over the Indian and Pacific Ocean. Multiple observational datasets are used to benchmark model performance through correlation coefficients (CC), Taylor statistics, skill scores, and rainfall distribution analysis. CMIP6 models show substantial improvements over CMIP5 in reproducing the spatial structure of ISMR, especially over the Western Ghats, Northeast, and Central India. The CMIP6 multi-model ensemble (MME) attains a higher correlation with observations (0.86) compared to CMIP5 (0.68). Empirical Orthogonal Function (EOF) analysis indicates that CMIP6 (CMIP5) captures dominant monsoon variability more realistically, with EOF1 explaining ~ 61.7% (58.2%) of variance and PC1 aligning more closely with observed anomalous years. Better representation of SST rainfall teleconnections is noted across the Arabian Sea (AS), Bay of Bengal (BoB), South China Sea (SCS), and Southern Indian Ocean(SIO) and matching well with the large-scale circulation features such as the low-level jet (LLJ) and tropical easterly jet (TEJ) by CMIP6. Overall, CMIP6 provides better advances in simulating monsoon dynamics and air sea interactions, though regional-scale variability and observational uncertainties still pose challenges.</p>