Stability Analysis in Space-Time on the Response of Winter Temperature in China to ENSO in the Past 50 Years

Based on the monthly mean temperature from 160 stations in China, oceanic Niño index (ONI) data from the Niño 3.4 region, and the NCEP/NCAR reanalysis data of 1962-2010, the stability of the response of winter temperature in China to the El Niño Southern Oscillation (ENSO) in the past 50 years is analyzed in space-time by using related analysis, sliding-related analysis, sliding t-test, composition analysis and other analysis methods. These analyses show that the response of winter temperature anomalies in China to ENSO differs significantly with respect to regionality and interdecadal changes. The relationship between winter temperature in China and ENSO is more unstable in northeast and southwest China than in eastern China. In the late 1970s, the response of winter temperature in northeast and southwest China to ENSO declined rapidly, even changing inversely, but remained stable in eastern China without obvious abrupt changes over the 50 years. The response of atmospheric circulation in Asia to ENSO also demonstrates obvious differences in regionality and interdecadal changes, in a pattern similar to the response of the winter temperature in China to ENSO. One possible explanation for the interdecadal change in the response of winter temperature in China to ENSO is atmospheric circulation. ENSO affects atmospheric circulation in the mid-high latitudes by Hadley circulation, which in turn affects winter temperature in China. After the late 1970s, the meridional Hadley circulation in the western Pacific weakened significantly, and as a result, the response of atmospheric circulation in Asia to ENSO also weakened, leading to the obvious decline in the response of winter temperature in China to ENSO.