More robust changes in the East Asian winter monsoon from 1.5 to 2.0°C global warming targets

Abstract

This study investigates changes in the East Asian winter monsoon (EAWM) under 1.5 and 2.0°C global warming (1.5 and 2.0GW) targets using multi‐model results from the Coupled Model Intercomparison Project phase 5 (CMIP5). It is found that the surface air temperature increases over the Asian continent and Pacific, and the precipitation increases over the northern Asian continent in winter during the 1.5 and 2.0GW periods. For the 1.5GW period, large uncertainties can be found in the projection of EAWM system members (i.e., Siberian high, Aleutian low, low‐level winds over eastern Asia, East Asian trough [EAT] and East Asian jet stream [EAJS]). For the 2.0GW period, more than two‐thirds of the models show that the Siberian high, the EAT and the meridional shear of the EAJS are weakened, but the Aleutian low is intensified. In addition, the intensified Aleutian low enhances low‐level northwesterly wind along the coast of northeastern Asia. Compared to those in the 1.5GW period, the EAWM system members show more robust changes during the 2.0GW period, except for the low‐level winds at mid‐latitude eastern Asia. These conclusions are suitable for both the RCP4.5 and RCP8.5 scenarios.

The mid-Miocene Zhangpu biota reveals an outstandingly rich rainforest biome in East Asia

“…Throughout this hyperthermal event, the Zhangpu area had a relatively equitable temperature and intensified monsoon rainfall, similar to those in the current climatic change predictions for South China, due to the continuing strengthening of the East Asian monsoon (20). However, there are differences and large uncertainties (including local temperature and precipitation) among different climate models regarding change within South China (20,21); our results may provide constraints on these projections of South China including precipitation and mean annual temperatures for the coming century.…”

Impact of Stratospheric Aerosol Injection on the East Asian Winter Monsoon

“…Both the changes in AL and SH are robust, causing the reduced zonal pressure gradient and southerlies over mid-latitude East Asia under the SSP5-8.5 scenario (Figures S3c and S3d in Supporting Information S1). In the middle troposphere, the 500-hPa relative vorticity is used to examine the EAT change instead of geopotential height, avoiding the overall effects of greenhouse gas-induced warming or SAI-induced cooling on the isobaric surface (Lu et al, 2008;Miao et al, 2020). As shown in Figure S3e in Supporting Information S1, the 500-hPa relative vorticity decreases over the Huaihe River valley and extends to Japan in SSP5-8.5, thus suggesting a shallower EAT.…”

Inter‐model spreading of changes in East Asian winter monsoon circulation under 1.5 and 2.0°C global warming targets

“…The results are consistent with the findings of Miao et al . (2020). Accordingly, easterly (westerly) anomalies dominate south (north) of about 25°N over the East Asia–western North Pacific region, with a center located over the Indo‐China Peninsula to South China (east of Northeast China) (Figure 1a).…”

“…Miao et al . (2020) demonstrated the differences in the changes in the climatology and interannual variability of the EAWM from 1.5 to 2.0°C global warming under the RCP4.5 and RCP8.5 scenarios. Specifically, the weakened Siberian high and East Asian trough are more evident and robust under 2.0°C global warming than they are under 1.5°C global warming for the two RCPs, while the enhanced Aleutian low shows similar features under an additional 0.5°C warming.…”