Research On The Interdecadal Variation In The Response Of Winter And Summer Temperature In China To ENSO In Recent Fifty Years

Based on the monthly mean temperature of160stations over China, the oceanic Nino index(ONI)data in the Nino3.4region and the NCEP/NCAR reanalysis data of1962-2010, the Interdecadal Variation in the Response of winter and summer temperature in China to ENSO in the past fifty years is researched by using related analysis、sliding related analysiss、liding T-test、 composition analysis etc. The analysis shows that the response of winter temperature anomaly in China to ENSO differs significantly in 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 late1970s, 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 in recent fifty years. The response of the atmospheric circulation in Asia to ENSO also demonstrated obvious difference in regionality and interdecadal changes, in a pattern similar to the response of winter temperature in China to ENSO. So the possible explanation about interdecadal change of the response of winter temperature in China to ENSO is the atmospheric circulation that ENSO affects the atmospheric circulation in mid-high latitude by Hadley circulation, which in turn affects winter temperature in China. After the late1970s, the meridional Hadley circulation in the western Pacific weakened significantly, as a result, the response of atmospheric circulation in Asia to ENSO also weakened, which lead to the obvious decline of the response of winter temperature in China to ENSO.The response of summer temperature anomaly in China to ENSO differs significantly in regionality and interdecadal changes. The relationship between summer temperature in China and ENSO is more unstable in northeast、North China and Yangtze river basin、South China, which break rapidly in the late1970s、in the early1990s and in early2000, in other region, the relationship between summer temperature in China and ENSO is relatively stable. The response of the summer atmospheric circulation in Asia to ENSO also demonstrated obvious difference in regionality, which similar to the response of summer temperature in China to ENSO. The summer atmospheric circulation in Asia also break rapidly in the late1970s、in the early1990s and in early2000. Contrast to winter, the response of summer temperature and atmospheric circulation to ENSO is more complex and mutation is more frequently.It is important to note that although the response of summer temperature to ENSO similar to the atmospheric circulation to ENSO, which namely has the same turning year, the response trend of them to ENSO do not as well as the winter conditions. The reason is that the summer atmospheric circulation is more complex than the winter atmospheric circulation, and in addition to El Nino, there are other factors such as Pacific SST, Monsoon variation, Tibet Plateau snow cover that affect summer temperature in China.