Plateau Meteorology

24 March 1989, Volume 8 Issue 1 Previous Next

SOLAR RADIATION BUDGET OVER THE QINGHAI-XIZANG PLATEAU REGION
Zhong Qiang
1989 Vol. 8 (1): 1-12.
Abstract ( 209 ) PDF (855KB) ( 410 )
The solar radiation budgets at the top of the atmosphere, at the surface and within the atmosphere over the Qinghai-Xizang Plateau during the period from August 1982 to July 1983 were investigated on the basis of monthly mean planetary albedo data from Nimbus -7 and the satellite derived global solar radiation and surface albedo. Results show that the appearing of the minimum planetary albedo in the transition season (May) plays an important role in modulating the solar radiation budget over the Plateau.For annual mean, the ratio of solar radiation reflected by the earth-atmosphere system to that absorbed by the atmosphere and by the surface is 37:18:45. The parameterizations of monthly mean absorbed solar radiation within the atmosphere and at the surface are presented in simple models describing them through the planetary albedo on the basis of regression analysis.

THE HEAT SOURCE AND MOISTURE DIAGNOSTIC ANALYSES OVER TIBETAN PLATEAU AND ITS SURROUNDINGS FOR MAY-JULY 1979
Wang Xiangdong;Luo Siwei
1989 Vol. 8 (1): 13-26.
Abstract ( 251 ) PDF (941KB) ( 281 )
In this paper we have calculated and diagnostically analysed the heating field and moisture transportation by using the datasets Ⅲ_b of FGGE for 15 May through 20 July 1979 in the domain 15-60°N and 60-120°E.The method is the same as used by Luo H. B. and Yanai M. but the domain is divided into 10 subregions.The analysed results show: (1) During this time the heat source in Tibetan Plateau is the strongest in SE-Asia and appears earlier than its surrouding area. (2) The upward vertical velocity and moisture in Tibetan Plateau are also the strongest of the same level in SE-Asia. It makes the moisture converge toward the Plateau from the surrounding regions in lower layer, especially from the south side around Bengal in 700-500 hPa layer. The moisture is transported upward over Tibetan Plateau and then diverges eastward in upper troposphere.The intensity of upward transportation of moisture over Tibetan Plateau is stronger than the area around Bengal and we think that the Tibetan Plateau plays a role of chimney in transporting moisture upward.

EXPERIMENT AND SCHEME OF STATISTICAL ASSIMILATION OF DATA IN TIBETAN PLATEAU AND ITS SURROUNDINGS
Huang Min;Luo Siwei
1989 Vol. 8 (1): 27-38.
Abstract ( 221 ) PDF (855KB) ( 476 )
In this paper a preliminary scheme of statistical assimilation for height and wind field on 500 hPa in Tibetan Plateau is given by use of Cressman's successive correction and truncation principle of expansion of empirical orthogonal function (EOF) and is applied to correct the FGGE Ⅲ_b data in the area of Tibetan Plateau and to separate circulation scale.Based on this a 24 h numerical experiment has been performed and it proves preliminarily that this method is worthy to be applied in certain degree.

THE EFFECTS OF TOPOGRAPHY AND HEATING COMPONENTS ON THE FORMATION OF SUMMER MONSOON IN ASIA-AFRICA
Shen Rujin;Ji Liren
1989 Vol. 8 (1): 39-51.
Abstract ( 382 ) PDF (1006KB) ( 530 )
A 5-level primitive equation model in σ-coordinates is used to study the effects of topography and different heating components on the formation of summer monsoon over Asia-Africa, as a part of the research on medium-range variation of the monsoon circulation. It is found that the model simulates successfully the major features of the summer monsoon circulation and systems over Asia-Africa. The pure dynamic effect of topography can not reproduce the details of summer monsoon, but provides some backgrounds of it. After incorporating the heatings (sensible heating and latent heating) into the model, the model figures out the main characteristics of summer monsoon, indicating the significance of heating forcings on the formation of them, in which sensible heating may be responsible mainly for the characteristics of circulation near the Tibetan Plateau and its adjacent areas and latent heating especially for those in the lower latitudes.

THE RELATION BETWEEN ENSO PHENOMENA AND SUMMERY PRECIPITATION OF GANSU PROVINCE
Zhu Bingyuan;Li Dongliang
1989 Vol. 8 (1): 64-69.
Abstract ( 341 ) PDF (393KB) ( 337 )
In this paper, we have analyzed the spacial distribution characteristic and the variations of the first time coefficients of total summery precipitation (June-August 1958-1986) by means of EOF for 31 stations of Gansu province. Compared the results with ENSO phenomena it turned out that the summery precipitation over the central section and the south east part of Gansu province was less than the normals considerably in the years of ENSO phenomena, but it was more than the normals in the following years.

THE SITE ERROR AND APPLICATION OF DIRECTION FINDER FOR GROUND FLASH
Qie Xiushu;Guo Changming;Zhang Guangshu;Peng Daohuo
1989 Vol. 8 (1): 70-74.
Abstract ( 363 ) PDF (408KB) ( 462 )
The DF network has been used widely, but in China, there are not any convenient and effective methods to estimate the direction error. This paper attempts to find a way to estimate site error, and get the distribution of site error versus direction in correlation by using data from weather stations.Using the data from network, we get the thunderdays and cloud-to-ground flash density within the detecting range of DF network. The cloud-to-ground flash density is in agreement with that got from other method.