亚洲上空夏季平均环流的结构及其热源分析

STRUCTURE OF THE MEAN CIRCULATION AND THE HEAT BUDGET IN JULY OVER ASIA

中文摘要:

      本文运用Boogaard的资料(对国内部分经过补充订正)和用连续方程计算了亚洲地区各层的垂直运动场。另外设计了一个间接计算热源的方法并计算了该地区的大气热源。在此基础上对亚洲地区夏季(7月)平均环流结构进行了研究。其主要结果如下:(1)在30°N以南地区西太平洋副热带高压的下沉主要来自东侧高空气流,也来自南侧的Hadley环流的上升支和高原及大陆上升气流,后两者均在300mb以下。而30°N以北,高原及大陆上升气流除了部分下沉于西太平洋地区外,主要在太平洋中部槽槽后下沉。(2)亚洲夏季(7月)大气热源中心在孟加拉湾北岸,而不在西藏高原的上空。

英文摘要:

      In this paper, the vertical velocity and the heat budget Q/Cp in July are evaluated. The climatological data used in this paper is given by Authors in China and is given by Boogaard in the other region. The aerological data in China is averaged for 1961-1974.For the calculation of the atmospheric heat source Q/Cp, a diagnostic equation is designed. The results are as follows: (1)There exists a massive scale heat source over southern Asia and its heating center is located over the north-eastern Bay of Bengal. The mean maximum heating is 3℃/day. It is about 1℃/day over the Tibetan plateau. By author's opinion, the thermal effect of the Tibetan Plateau in summer is overestimated in the previous studies.(2) The downdraft in the western Pacific subtropical high south of 30°N is mainly originated from the east-side upper current. Besides, the above downdraft is partly originated from the updraft in the Hadley cell and from the updraft over the Tibetan and mainland of China. The maximum height of the later two branches of the updraft is lower than 300 mb surface. In the region north of 30°N, the updraft originated from the Tibetan Plateau and the mainland of China is mainly descending behind of TUTT and paitly is descending in the western Pacific, but is not descending in the eastern Pacific. (3) There exists a strong updraft over southern Asia. The center of the upward motion is located over the northern Bay of Bengal, i.e., near the heating center, but is not located over the Tibetan Plateau. The intensity of the upward motion over the northern Bay of Bengal is much larger than that of over the Tibetan plateau. The above strong updraft is mainly descending over the southern Indian Ocean South of 10°S.