Synergistic Influences of the Sea Surface Temperature Anomalies in the North Atlantic and the Indian Ocean on Summer Precipitation in Central Asia

Based on the Global Precipitation Climatology Centre (GPCC) monthly precipitation data, the Extended Reconstructed Sea Surface Temperature (SST) version 5 (ERSSTv5) dataset derived from the National Oceanic and Atmospheric Administration (NOAA), and the Fifth‐generation European Centre for Medium‐Range Weather Forecasts (ECMWF) atmospheric reanalysis (ERA5) monthly dataset, the synergistic influences of the SST anomalies (SSTAs) in the North Atlantic (NA) and the Indian Ocean (IO) on summer precipitation in Central Asia (CA) are investigated. Results show that SST in both the NA and the IO positively correlates with summer precipitation in southern CA. The meridional movement of the subtropical westerly jet (SWJ) plays an important role in linking the SSTAs in the NA and the IO and summer precipitation in southern CA. The positive SSTAs in the NA can excite an eastward‐propagating wave train across Eurasia and cause an anomalous cyclone over CA, which is responsible for the southward movement of the SWJ. The positive SSTAs in the IO can induce an anomalous cyclone in the upper troposphere over the northwestern part of the South Asian summer monsoon region, according to the Gill‐type atmospheric response, and the SWJ over CA also moves southward. The southward movement of the SWJ over CA responds to the simultaneous SST warming in the NA and the IO. Furthermore, it can induce an anomalous cyclone in the middle troposphere over CA and strengthen the transport of water vapour from the Arabian Sea. Therefore, more summer precipitation can be observed in southern CA. In the process of synergistic influences of SSTAs in the NA and the IO on summer precipitation in CA, the former plays a more important role.