Long-term climatology of the spatially coherent extreme precipitation systems over the Central Indian region

Abstract:

This study addressed the extreme precipitation spatial extent over Central India by employing a precipitation system based approach (PSA) on the Indian Meteorological Department gridded rain-gauge dataset. Using the PSA algorithm, different spatial scale precipitation patterns were categorized into three types sporadic, intermediate, and massive systems based on their spatial extent. The spatial extent of extreme precipitation events (EREs) not only gives information about their size but also enables us to understand the individual extreme precipitation systems characteristics. The spatial distribution of EREs inside a precipitation system (referred to as intra-system) was analyzed with Max precipitation (PM), total precipitation (PT). For different size precipitation systems (referred to as inter-system), frequency (RF), intensity (RI), and their contribution to extreme rainfall (CER) were considered. The results showed that more coherence systems were found over the Central Indian with a larger frequency of sporadic EREs. ERE system characteristics showed regional variations that could be associated with local climate patterns. In general, for all central Indian region, the massive events PM is increasing, whereas their total system rainfall is having no trend in recent 30 years However, for intermediate and sporadic systems PM and PT both are increasing, specifically in recent 30 years. In inter-systems characteristics, RF shows decadal variation for sporadic and intermediate, but a decreasing trend for massive EREs. In general, the intensity is increasing for all categories of EREs. Interestingly, the intensity of sporadic and intermediate is increasing much faster in recent 30 years.