亚澳季风区大气视热源的季节演变特征

对1950-2000年平均的亚澳季风区大气热源的季节演变和突变特征进行分析.结果发现,亚澳季风区热带低纬的大气热源区随季节由冬到夏而自南半球向北半球移动,在盛夏达到最北,强度也最强,并在春末与北半球中纬度的热源区汇合,到秋季开始南撤;东亚季风区和印度季风区大气热源的冬夏型间转换的过度季节都较短,冬夏型间转换具有明显的突变性,而印度季风区大气热源的冬季型维持时间明显比夏季型要长;亚澳季风区内大气热源的年较差以亚洲季风区的热源年较差最显著,澳大利亚北部次之.

Seasonal Variability of Atmospheric Heat Sources over the Asian-Australian Monsoon region

The seasonal variability of atmospheric heat sources over the Asian-Australian monsoon region is analyzed using 51-year NCEP/NCAR reanalysis data. The heat source belt in Southern Hemisphere low latitudes of Asian-Australian monsoon region moves northward with increasing strength from boreal winter to summer, and reaches the north-edge in boreal summer with strongest strength. In late spring, this belt converges with the heat source belt from the mid-latitudes of Northern Hemisphere. From boreal fall to winter, the heat source belt in Northern Hemisphere low latitudes then withdraws southward. The transition seasons between the winter-pattern and the summer-pattern of heat sources over East Asian monsoon region and Indian monsoon region are short and the transitions between the winter-pattern and the summer-pattern of heat sources are of abruptness. In Indian monsoon region, the winter-pattern of the heat sources maintains longer than the summer-pattern. The annual range of the heat sources over Asian monsoon area is the most prominent.