大连地区冬季气温异常与前期印度洋海温的关系

Relation of Winter Temperature Anomaly in DaLian to Prophase SST over Indian Ocean

利用近40a全球海温、500hPa高度场、300hPa纬向风场和海平面气压场月平均资料以及大连地区冬季的气温资料,分析了大连地区冬季气温异常的变化特征,探讨了大连地区冬季气温异常与前期印度洋海温异常的相互联系。结果发现:影响大连地区冬季气温的海温异常关键区位于5°S^5°N、60°~75°E,关键影响时段为当年的4~7月;长时间的海气相互作用使前期的海温异常影响了后期的大气环流,在关键海区冷、暖水年,海平面气压距平场、500hPa高度距平场、300hPa纬向风距平场都存在着显著的差异;其中西伯利亚高压、极涡的位置、东亚大槽的强弱、极锋急流都差异显著,从而导致大连地区冬季气温的异常。

The variation of winter temperature in Dalian is analyzed by using the data set of the monthly mean global sea surface temperature （SST）, NCEP/NCAR reanalysis data and winter temperature data in Dalian from 1960 to 2000. The possible relations between winter temperature anomalies in Dalian and prophase SST over the Indian Ocean are also studied. It is found that waters within 5°S - 5°N, 60° - 75°E are the key areas of sea surface temperature anomaly （SSTA） that affect the winter temperature of these regions from April to July. Through the long-term air-sea interactions, the prophase SSTA affected the later general circulation. There are significant differences in the sea-level pressure anomaly （SLPA）, height anomaly at 500 hPa and zonal wind anomaly at 300 hPa fields in the warm/cold years in the key areas, especially notably differences in the Siberia high, East Asian trough, polar-front jet and the locations of polar vortices, resulting in winter temperature anomalies in Dalian.