Projection of midsummer precipitation by CMIP6 models and analysis its sources of uncertainty in the northern China monsoon region

The projection of mid-summer precipitation trend is slight increasing in the near-term (2021-2040), maximum in the mid-term (2041-2060) and slowing down in the long-term (2080-2099) over northern China monsoon region (NCMR), and its mean increasing trend is projected to be 3% (5%) under different scenarios in the near-term (middle-term), and slightly decreases to 2% in the long-term. Especially, it is sensitive to temperature change under SSP1-2.6 scenario, which may be related to the small amount of temperature change under this scenario. Under the background of global warming, the optimal model projection enhancement trend, which is caused by dynamic responses, and partly offset by thermodynamic responses. The projection uncertainty of mid-summer precipitation is the largest under SSP5-8.5 in the long-term over NCMR.