Evaluation and future projection of the extreme precipitation over India and its homogeneous regions: A regional earth system model perspective

A regional earth system model (ROM) was used to examine the projected change in the precipitation extremes (PEs) and associated dynamical and thermodynamical processes over India during the Indian summer monsoon (ISM). In this regard, PEs are computed for India, its six homogeneous regions and subregions the Western Ghats (WG) and central India (CI). The changes are computed for mid‐future (2040–2069: MDF) and far‐future (2070–2099: FRF) with respect to the historical period (1969–2000). ROM showed better resemblance with observation in simulating PEs over other regional climate models (RCMs) that participated in the CORDEX‐CORE simulation. The intense rainfall (95th percentile: R95) is expected to be enhanced over most of the region during MDF that further intensifies in FRF except CNE (central northeast) and NEI (northeast India), where the increase in R95 was restricted only up to MDF. Interestingly, very intense rainfall (99.9th percentile: R99) showed robust increases in both MDF and FRF for all regions. Additionally, long wet (dry) events were shortened (lengthen). Moreover, the short wet and dry spell frequency has increased, while the duration of the wet (dry) spell has decreased (increased) in both time slices over India with noticeable regional variation. This is attributed to the strong cyclonic circulation, reduced vertical wind shear and enhanced moisture transport during the ISM in both time slices. It is very important to highlight the substantial changes in the precipitation extremes to have better planning and strategies that will be helpful to minimize the incurred losses. Graphical highlights of the study conducted using the high‐resolution coupled land–ocean–atmosphere regional earth system model (RESM). This study is fragmented into three important subsections. First of all, the reliability of RESM in capturing the extreme rainfall over and its homogeneous regions was checked with respect to the precipitation data from India Meteorological Department (IMD). We found that the RESM has ability to capture the extreme rainfall over all the regions. Furthermore, the changes in extreme precipitation in the mid and far century were demonstrated and found that there will be more intense rainfall in mid and far future. Moreover, we made an attempt to unfold the causes of the changes that lead to exaggerated PEs.