Intercomparison of CORDEX-CORE and CORDEX-SA model experiments in assessing Indian summer monsoon

Abstract

The present study compares two different modelling suites such as Coordinated Regional Climate Downscaling Experiment-South Asia (CORDEX-SA) and Coordinated Regional Climate Downscaling Experiment-Coordinated Output for Regional Evaluation (CORDEX-CORE) to represent ISM rainfall (ISMR) over India and monsoon core zone (MCZ) and examine for the subsequent improvement in high-resolution CORDEX-CORE. The model performances are evaluated on the basis of the presentation of spatial and temporal distribution, interannual variability (IAV), and intraseasonal oscillation (ISO) during the historical (present) period (1979–2005). The spatial distribution of precipitation is better represented in the high-resolution CORDEX-CORE than CORDEX-SA, and Consortium for Small Scale Modelling (COSMO) model experiments resemble more to the corresponding Indian Meteorological Department (IMD) observation. Highest magnitude of grid-specific correlation coefficients over India as well as MCZ are found for MPI-ESM-LR_COSMO and ERAINT_COSMO members under CORDEX-CORE Regional Climate Model (RCM) framework. The shifting of precipitation maxima from July–August to August–September is captured in IMD observation; however, none of the models is able to capture this precipitation shift. CORDEX-CORE suites show better evolution of active and break spells than CORDEX-SA. An improvement is observed in CORDEX-CORE modelling suite in representing spatial distribution, intraseasonal oscillation. COSMO model experiments outstand all other model experiments.