Characteristics and projected changes in maximum daily precipitation across the globe

Research indicates a notable rise in extreme precipitation events across the globe in association with a warmed climate. A considerable chunk of such assessments focuses either on global land areas or specific regions, and these have often been reported on an annual basis. However, it is crucial to note that significant monthly variations occur in the precipitation regimes, especially during seasonal transitions. This research evaluates the statistical characteristics of extreme precipitation globally in observations and Coupled Model Intercomparison Project Phase 6 model projections. Our assessment focuses on maximum daily precipitation on an annual, seasonal, and monthly scale globally for both historical and future climate in the 21st century. The historical assessment is conducted based on the 1980-2014 period, whereas the future climate is sectioned into near future (2040-2060) and far future (2070-2090) focusing on two emission scenarios: SSP245 and SSP585. Monthly assessments of maximum daily precipitation indicate an expansion in the probability density curve's width starting from the boreal winter season going into the peak-to-late summer season both in observations and model simulations. Transitioning between unimodal and bimodal distributions in density curves indicates the appearance of one more class of grid points that receive higher precipitation; for example, over the land. Despite large inter-model spread, future projections assessed based on multimodel mean reveal a substantial rise in maximum daily precipitation in a warmer climate. The reported increase in the intensity of maximum daily precipitation compared with historical climate outweighs the decrease by at least a factor of 1.2 in both scenarios, which is, further, more prominent in SSP585. A large decrease and increase in the intensity of extremes indicates that it may become more variable and intense in future. Additionally, land regions, particularly along the intertropical convergence zone and global monsoon domains, are expected to exhibit more pronounced intensification in future, whereas the decline is mostly confined to tropical-subtropical oceanic regions.