夏季赤道太平洋、北极及高原地区热状况对西北太平洋副高及我国降水的影响

THE INFIUENCE OF THE THERMAL CONDITIONS OVER THE EQUATORIAL PACIFIC OCEAN, ARCTIC SEA AND TIBETAN PLATEAU ON THE NW PACIFIC SUBTROPICAL HIGH AND THE PRECIPITATION OVER CHINA DURING THE SUMMER SEASON

本文利用一个全球大气环流谱模式，对七月份赤道太平洋海温异常、北极海冰异常及高原积雪对西北太平洋副高和我国降水的影响进行数值试验，得出一些很有意义的结果。例如，当赤道东或西太平洋海表温度出现负距平时，副高较趋近负SSTA区，当出现正距平时，副高则远离正SSTA区；北极海冰覆盖面积较大时副高位置偏南，覆盖面积较小时副高位置偏北等等。试验结果表明：在作气候预报，特别是夏季风环流与降水预报时，必须考虑SSTA、极冰覆盖面积及高原热状况的综合效应。

By using a global spectral AGCM, a numerical experiment is performed on study of the influence of the anomalies of equatorial Pacific SST, arctic sea ice and Tibetan snow cover in July on the NW Pacific subtropical high and the precipitation over China. The results ob tained are of great significant importance. For example, the subtropical high will move to ward the region of negative SSTA if a negative SSTA region appears either over the eastern or the western equatorial Pacific. If the SSTA is positive, the high will move apart from the region of possitive SSTA. When the extent of arctic sea ice is of positive anomaly, the sub tropical high will take a position south of normal, and if it is negative, the high will take a position north of normal. So the experiment results indicate that one should consider the synthetic effect of the equatorial Pacific SST, the extent of arctic sea ice and the Tibetan snow cover in climate prognosis, especially in prognosis of the summer monsoon circulation and precipitation.