我国气候对北太平洋海温的响应的模拟试验

利用联邦德国汉堡大学气象研究所大气环流模式的气候模拟的结果，就模式中我国气候对北太平洋海温异常的响应进行了分析，目的在于研究我国气候的成因。我国气候对海温的敏感性试验由异常算程和对照算程组成。异常算程是在北太平洋多年平均海温场上迭加一个“东温西凉”型的异常值，而对照算程中则为多年平均海温场。试验结果指出，1月300百帕上青藏高原两侧的南北两支急流大大增强，Hadley环流减弱，500百帕环流和850百帕温度场出现类似冷冬的形势，即经向环流加强，南北温度梯度加大，我国大部分地区的1月气温降低。但湿度场对北太平洋海温异常的响应甚弱，这与通常的看法一致，即冬季我国干旱主要是由于蒙古干冷高压频频入侵造成的。

A Simulation on the Response of the Climate of China to the SST Anomaly in the North Pacific

By utilizing the result simulated by GCM of Meteorological Institute of Hamburg University, the response of the model climate of China to the SST anomaly in the North Pacific is analysed in order to understand the cause of formation of climate in China. The sensibility experiment consists of anomaly run simulated by superposing an anomaly called the “east warming and west cooling” pattern to the multiyear mean SST field and control run simulated by without the anomaly. The experimental result point out that the two branches of jet around the Qinghai-Xizang Plateau at 300 hPa in January greatly increases its intensity and the Hadley circulation weakens. Consequently, the at 500 hPa and the temperature pattern at 850 hPa resembles the winter pattern, i.e., the meridional circulation and the north to south temperature gradient are strong accompanying with decreasing of the temperature over most parts of China in January. Nevertheless merely weak response of the humidity field to the SST anomaly in the North Pacific is found, it is in agreement with the usual view that the drought in China in winter is caused by frequent invasion of the dry cold anticyclone from Mongolia