亚洲季风区大气热源和水汽汇的季节内变化——Ⅰ.大气热源的季节内变化

INTRASEASONAL VARIATIONS OF THE ATMOSPHERIC HEAT SOURCES AND MOISTURE SINKS OVER ASIAN MONSOON REGION PART I : HEAT SOURCES

用ECMWF1980—1983年资料讨论了亚洲季风区大气热源的季节内变化特点。分析表明,季节内变化显著区主要限于季风活跃区及其附近地区,并且存在季节、年际差异.EOF分析的主要空间型反映了印度到中南半岛一带、中国东部、西太平洋地区的振荡存在一定的关系。相应时间系数功率谱分析表明大气热源主要存在30—60天振荡,但1980年夏半年和1982—1983年ENSO事件期间(尤其是冬半年)这一振荡不显著。夏半年亚洲季风区30—60天变化的传播并不一定向东,而是存在明显的地区差异.

Using the ECMWF data of 1980 to 1983,the intraseasonal component of the variation of the atmospheric heat source f4Q1f5 (vertically integrated) over Asian monsoon region is examined in detail . The large intraseasonal variance of f4Q1f5 is mainly confined over the active monsoon region of Asia and surround areas , and varies seasonally and interannually . The EOF analysis indicates the relationship of intraseasonal oscillations between regions cf India-Burma, the coast of East China and the western Pacific . The spectral analysis of the EOF time coefficients reveals that the dominant period range is around 30-60 day except for the summer of 1980 and the 1982-1983 ENSO period. The propagation of 30-60 day fluctuation in summer varies from region to region by means of lagged correlation analysis.