Delving into Recent Changes in Precipitation Patterns in the Western Himalayas under Global Warming

Abstract

Western Himalayas (WH) have experienced a two-fold temperature increase compared to the Indian sub-continent post-2000, strongly linked to global warming with significant implications for precipitation patterns. Using ERA5 reanalysis, we examine seasonal precipitation changes in the WH between recent (2001–2020) and past decades (1961–2000). Mean summer precipitation has increased over foothills but declined at higher elevations, while winter precipitation has increased region-wide except in certain parts of Jammu-Kashmir (JK), Uttarakhand (UK), and Punjab. In summer, light precipitation has increased in JK, while moderate precipitation has decreased over foothills but enhanced at higher altitudes. Moreover, extreme precipitation has significantly increased in the UK and Himachal Pradesh. During winter, light and extreme precipitation has increased, while moderate and heavy precipitation declined. Maximum one and five-day precipitation extremes (Rx1day, Rx5day) have increased in the foothills with more consecutive wet days. Winter extremes have increased in the northern region, while consecutive dry and wet days have declined, except for specific areas in eastern Ladakh and JK. Furthermore, rising sea surface temperatures, enhanced moisture transport, increased precipitable water and cloud cover in WH are associated with increasing mean and extreme precipitation, emphasizing the impacts of global warming on temperature and precipitation transitions in the region.