Projected Changes in Asian Summer Monsoon in RCP Scenarios of CMIP5

Responses of the Asian Summer Monsoon (ASM) in future projections have been studied based on two core future projections of phase five of the Coupled Model Intercomparison Project (CMIP5) coordinated experiments with the IAP-coupled model FGOALS_s2 (the Flexible Global Ocean-Atmosphere-Land System Model). The projected changes of the ASM in climatological mean and interannual variability were respectively reported. Both the South Asian Summer Monsoon (SASM) and the East Asian Summer Monsoon (EASM) were intensified in their climatology, featuring increased monsoon precipitation and an enhanced monsoon lower-level westerly jet flow. Accordingly, the amplitude of the annual cycle of rainfall over East Asia (EA) is enhanced, thereby indicating a more abrupt monsoon onset. After the EA monsoon onset, the EASM marched farther northward in the future scenarios than in the historical runs. In the interannual variability, the leading pattern of the EASM, defined by the first multi-variable EOF analysis over EA, explains more of the total variances in the warmest future scenario, specifically, Representative Concentration Pathway (RCP8.5). Also, the correlation coefficients analysis suggests that the relationship between the EASM interannual variations and ENSO was significantly strengthened in the future projections, which may indicate improved predictability of the EASM interannual variations.