Future Increase in Post-Drought Precipitation With a Stronger Response to Warming

According to observational evidence and climate model projections, the frequency and intensity of the rapid shift from drought to pluvial (rapid dry-wet alternation, RDWA) increases as warming intensifies. Given that post-drought precipitation is a key cause of RDWA, this study focuses on changes in post-drought precipitation. Climate model projections indicate that the mean post-drought precipitation will increase by 15.3% during 2071-2100 under the Shared Socio-economic Pathway (SSP) 585 scenario. The scenario-averaged response rate of post-drought precipitation (4.6%/K) to global warming is significantly greater than that of general precipitation (2.7%/K). Furthermore, there will be an increase in the proportion of land area experiencing maximum post-drought precipitation in autumn. The mean post-drought extreme precipitation will increase by 20.5% under SSP585, exacerbating the severity of RDWA in a warmer world. The post-drought thermodynamic (precipitable water) and dynamic (atmospheric vertical velocity) components are both conducive to the future increase in post-drought precipitation. Post-drought precipitation can directly cause the shift from drought to pluvial (dry-wet alternation), leading to agricultural losses and natural hazards such as landslides. Therefore, understanding and quantifying how it will change in the future is important. Our results find that mean post-drought precipitation will increase by about 15.3% and more than half of droughts will be accompanied by extreme precipitation in the following month by the end of the 21st century under high emission scenario. More maximum post-drought precipitation will occur in autumn, potentially affecting agricultural activities and threatening food security in the future. The response of mean post-drought precipitation to global warming is stronger than that of general precipitation. Our further analysis suggests that under a warming climate, post-drought atmospheric conditions are favorable for rainfall formation after droughts. An increase in post-drought precipitation will exacerbate the frequency and intensity of rapid dry-wet alternations The future mean response of post-drought precipitation to warming (4.5%-4.7%/K) is stronger than that of general precipitation (2.1%-3.1%/K) Increased precipitable water and atmospheric vertical velocity favor the increase in post-drought precipitation