Projections of Temperature and Precipitation over Xinjiang Based on CMIP6 Models

In this study, we project the changes in temperature and precipitation over Xinjiang during the period 2015–2099 relative to the historical period 1995–2014 using 20 global climate models, which have exhibited good performance in simulating climatological temperature and precipitation over this region, from the Coupled Model Intercomparison Project Phase 6 (CMIP6) under the three shared socioeconomic pathways (SSPs). Multimodel median results indicate that annual and seasonal temperatures will increase during the 21st century, with larger values in the basins than those in the mountains. The trends of annual temperature changes under SSP1-2.6, SSP2-4.5, and SSP5-8.5 are expected to be 0.1°C (10 a)⁻¹, 0.3°C (10 a)⁻¹, and 0.7°C (10 a)⁻¹, respectively. The regionally averaged temperature will increase by 1.3°C, 2.6°C, and 5.3°C, respectively, during the period 2080–2099, with the strongest warming occurring in the summertime. The regionally averaged consistency in the sign of the projected annual and seasonal temperature changes is greater than 90%, and the inter-model uncertainty will increase with time, with larger values occurring under SSP5-8.5 than those occurring under SSP1-2.6 and SSP2-4.5. Except for springtime, larger uncertainties occur in the projection of seasonal temperatures than that in the annual case. Precipitation is expected to increase over Xinjiang during the 21st century. The projected maximum increase of more than 50% will be located in the central Tarim Basin under the SSP5-8.5 scenario during 2080–2099. Under the SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios, the trends of changes in annual precipitation from 2015 to 2099 are 0.2% (10 a)⁻¹, 2% (10 a)⁻¹, and 4% (10 a)⁻¹, respectively, and annual precipitation increases by a regional average of 5%, 13%, and 25% during 2080–2099. The largest increase in precipitation will occur in winter. The inter-model consistency in the sign of projected annual and seasonal precipitation changes increases with time but is weaker than its temperature counterpart. The inter-model uncertainty for precipitation projections is expected to increase with time, with the largest magnitude occurring under SSP5-8.5. The inter-model uncertainty of seasonal precipitation projections is larger than that of annual projections.