An empirical study of the response of the South China Sea summer monsoon to the remote forcing

A self-consistent mechanistic model is considered for the response of the South China Sea (SCS) monsoon to the remote forcing. The feedback parameters are evaluated by using an atmospheric general circulation model (AGCM) control run, AGCM sensitivity experiments, and observation data of the NCEP reanalysis and ICOADS sea surface temperature (SST). Zonal wind anomaly induced over SCS from the surrounding weather system without any effect from SCS precipitation anomaly is regarded as the remote forcing for SCS monsoon. The remote forcing directly affects SCS monsoon variability through the water vapor transport and Convective-Wind-Evaporation (CWE), and indirectly through the reduction of SST. The effect of the activated zonal wind induced-reduction of SST is much smaller than that of CWE and plays a role in suppressing SCS precipitation. This result suggests that the SST reduction contributes to stabilize the monsoon variability over SCS in summer through local air-sea coupling. On the other hand, present study also suggests that monsoon precipitation contribute to reduce SST through the change in the local circulation.