A PRELIMINARY EXPERIMENTAL SIMULATION ON THE HEATING EFFECT OF THE TIBETAN PLATEAU ON THE GENERAL CIRCULATION OVER EASTERN ASIA IN SUMMER

Abstract

In summer the Tsinghai-Tibetan Plateau is a giant heat source. It has important influence on the circulation over Eastern Asia. This has been studied synoptically in many aspects. In the present paper we simulate this effect in a rotating annulus. A semi-ellipsoidal body is used for simulating the Tsinghai-Tibetan Plateau. The rcsistance wires are buried under its surface for hcating the plateau.Our experiments show that some of the important features of the summer circulation over Eastern Asia such as the heat low and the huge high in the lower and upper levels respectively over the plateau, northward retreat of the strong westerlies therc in summcr, the building of the easterlies in the upper troposphere and the monsoon meridional circulation (in revcrsed direction of Hadley circulation) to the south of it, are all internally related. The key-point in their relation is the heat source of the plateau. It is also seen in our expcriment that the southwest monsoon and even the northward push of rainfall belt in summer over China may also be related to this heat source.The main agents for the upward transport of heat from the heat source are the strong convective wcather systems. Thcre is also some indication in our experiment that these medium and small-scale convective systems are responsible for the maintenance of the large-scale circulation over the platcau.urther, the synoptic experience of the slowing down of the long trough as well as its cut-off by the plateau has also been simulated in our experiment.