East Asia and Western Pacific METEOROLOGY AND CLIMATE

58
TOE MEAN HEAT SOURCES OVER ASIAN MONSOON REGION
DURING THE PERIOD FROM APRIL TO OCTOBER OF 1980-1983
HUIBANG
LUO
Department of Atmospheric Sciences,
Zhongshan University,Guangzhou,China
ABSTRACT
An ECHIfF data set giving u,v, *, t and RH at seven levels
on a 2.5X2.5 grid iesh in the doiain 5°S-45°H, 50 0 -13G°E froi
April through October of 1980-1983 is used in this study.'*'
is recoiputed to satisfy such an upper boundary condition that
there are no heat sources other than the radiative heating in
the uppermost layer between 100 and 2QQhPa. The apparent heat
source Qi and the apparent loist sink Qz are coiputed for
each day. Only annual leans of Qi and Qz are discussed in this
paper! the inter-annual changes of Qi and Qz are discussed in
another paper.
The lain findings are :
1. The regions of the pronounced integrated apparent heat
source (Qi) are located over the continent and islands during
the period of suner half-year, with a laxiiui of 20Q*/! 2
located over the Buna-Yunnan region.
2. The integrated apparent heat source (Qi) is relatively
siaii over the oceanic regions. Over the South China Sea region,
the values of (Qi) are relatively large along the latitude of
17.5°K with a laxiiui not exceeded lOO^/i 2 ,which is far sialler
than that over the continent.
3. The sensible heat flux is very iiportant in taking
Buna the laxiiui heat source center. Cuiulus convection is
also vevy strong over this region after the onset of the
suner lonsoon.
4. This study verifies that dry therial convection
originating near the heated surface is responsible for the
deep tropospheric heating over the Plateau during the preonset
phase even for the interannuai lean results.
1.Introduction
The distribution and the heating mechanism of the atmospheric
heat source over the Tibetan Plateau and surronding
areas, and their importance on the Asian summer monsoon
circulation have been discussed by many authors (e,g.» Flohn,
1968; Yeh and Gao et al., 1979i Chen and Li,1983; Luo and Yanai,
1984; Johnson et al, 1985: He at ah, 1987).. But there
exists discrepancy among different results, for instance,