THE CHARACTERISTICS OF THE ZONAL AND MERIDIONAL CIRCULATION OVER TROPICAL AND SUBTROPICAL REGIONS IN EASTERN ASIA IN SUMMER
DAO SHIH-YEN, HSU SHU-YING, KUO CHI-YUNN (Institute of Geophysics and Meteorology, Academia Sinica)
In this paper, an analysis is made on two main distinct flow patterns over the tropical and subtropical area in Asia and on its adjacent water. They occur respectively in the periods of July 8-18, 1958 and July 21-30, 1957. It is found that during these two periods there is marked difference in the characteristics of the tropospheric circulations. The position of zonal wind belt over the northern hemisphere, the distribution of long wave patterns, the activity of subtropical highs, and the distribution of the intertropical convergence zone are all quite different. At the same time, the activity of typhoons and other synoptic processes over the continent are also different.In addition, we found that there are some interactions between the northern and the . southern hemisphere. When low index circulation prevails over subtropics and tropics in Eastern Asia, there is meridional circulation in the southern hemisphere (especially in Australia), and there is a mass transport from the southern to northern hemisphere. While high index circulation prevails over northern hemisphere, zonal flow pattern prevails in the southern hemisphere.