Current Issue

• THE CHARACTERISTICS OF THE HEATING FIELD DISTRIBUTION AND ITS ANNUAL VARIATION OF THE ATMOSPHERE IN EAST ASIA
• Yao Lanchang;Luo Siwei;Wang Anyu
• 1982 Vol. 1 (3): 1-11. 
• Abstract ( ) PDF (745KB) ( )
• In this paper the atmospheric heat sources and sinks are calculated in detail for Jan.-Dec.over the East Asia with 10 year mean data of 1961-1970.Their characteristics and annual variation are also analysed and discussed.The main results are: 1.There are heat sources over the Plateau for April-September and sinks for the other months of the whole year.The heat sources and sinks mainly depend upon the sensible heat over the Plateau.The heat source over the Plateau appears early and strong and contributes to that the subtropical jet stream jumps over the Plateau from its southern side to the northern. In winter the sink over the Plateau is weaker than that over North India and there is little contribution to maintain ten subtropical jet stream to the southern side of the Plateau. 2.There are sinks for the whole year in Iran Plateau and the People's Republic of Mongolia, because in this region the sensible and latent heats and their annual variations are smaller than the radiation cooling. 3.The annual variation of the heating field in India and East China depends upon the change of precipitation. There are heat sources in North India for June-September.In Bengal the heat source appears in April and strengthens in May, but its area is much smaller than the Plateau. The heat source of the Bengal is very strong in June-July.We think that it is not the cause of the trigger mechanism of the onset of the raining season but being its result, because the onset of the raining season appears at the beginning of June.

• THE EFFECT OF THE LAND-SEA DISTRIBUTION AND PLATEAU ON THE MEAN MERIDIONAL CIRCU-LATION IN THE LOW LATITUDE IN JULY
• Luo Siwei;Yao Lanchang;Lü Shiiua
• 1982 Vol. 1 (3): 12-21. 
• Abstract ( ) PDF (679KB) ( )
• In this paper, the mean meridional circulation and some physical parameters are calculated in the global latitude zone 45°-40°S for the July mean fields of 1961-1974. The analysed results show that the effect of the large scale land-sea distribution and Plateau on the mean meridional circulation is very clear.There exists a Hadley cell being symmetric in both Hemispheres, as soon as the underlying surface in large scale is symmetric in both Hemispheres no matter where is water or land, such as in Eastern pacific Ocean, Atlantic Ocean and the Europe and Africa. In Asia there is a typical monsoon circulation.This is due to that the underlying surface of Asia in latitude belt 20°-40°is land and Plateau which generates the heat source and ascending motion instead of the sink and descending motion in the subtropical belts in the other parts of the globe.In America and western Pacific Ocean there are monsoon circulations too, but it is very weak over America.Owing to the effect of monsoon circulation the global mean Hadley cells in both Hemispheres are not symmetric and the southern one is much stronger than the northern. The upward energy transportation in the monsoon circulation is very large, and it is largest in strength, the highest and the farthest in horizontal over the Plateau.We think that the Qinghai Xizang Plateau plays a chimney effect for the energy transportation outward in the upper troposphere.

• APPLICATION OF THE MONTHLY MEAN OF HEATING FIELD OVER NORTHERN HEMISPHERE IN THE LONG-RANGE WEATHER PREDICTION
• Zhang Jiabao;Weng Wanjun
• 1982 Vol. 1 (3): 22-32. 
• Abstract ( ) PDF (772KB) ( )
• In this paper, we use the computed data consisting the monthly mean in many years of the average atmospheric heating field in the troposphere, the field of departure in month by month over the years, the amplitude of wave spectrum, etc, to make an analysis and a comparison with the climatic anomaly of some areas in our country.The results point out that in the earlier stage of climatic anomalyappeared at somewhere the monthly mean of the theating field,flow field or the heating field's amplitude of wave spectrum over northern hemisphere displays a definite abnormal feature, while that in unusual years of identical type is consistent.These results,therefore, have a omen significance.

• A METHOD FOR WEATHER MAP OBJECTIVE ANALYSIS DESIGNING IN SEGMENT
• Li Guojie;Zhou Jiayu
• 1982 Vol. 1 (3): 33-42. 
• Abstract ( ) PDF (639KB) ( )
• A new objective analysis method based on the surface fitting by D. Shepard is presented in this paper.It has the feature of the method to simulate artificial analysis.In the process,meteorological principle is observed, and some people's experiences are drawn.The difference from the others is to divide the procedure of artificial analysis into several stages and simulate them bit by bit. In mathematics, that is,a field of physical quantity is described by means of a piecewise continuous compound function. Due to adopting the technique of piecewise design, a lot of main ad-vantages can be summed up from other objective analysis methods now available, such as: (1)a preliminary field is unnecessary, (2)the station records are unchanged in the result, (3)it can make a reasonable value higher (lower) than adjacent stations on general net point which is in the centre of high (low) value region, etc.Moreover, it also can use inconven-tional data conveniently and deal with missed records flexibly, therefore this method may be supplied to practical operation.

• THE RELATIONSHIP BETWEEN THE FLOW PATTERN VARIATION OVER LOWER TROPOSPHERE IN LOW LATITUDES AND THE PERSISTENT DROUGHT AND FLOOD IN THE MIDDLE AND LOWER YANGTZE VALLEYS
• Yang Guangji;Liang Peidian
• 1982 Vol. 1 (3): 43-51. 
• Abstract ( ) PDF (630KB) ( )
• In this paper, the persistent droughts and floods in large area in the Middle and Lower Yangtze Valleys during summers of 1972,1978,1969,1980 are investigated respectively. The general circulation characteristics during winter, spring and summer for above four years are compared with each other by using 850mb stream line charts for every February,April,June and July of 1972,1978 and 1969, 1980.It is found that the strength and range of the northward crossing equatorial flow from Southern Hemisphere is an important factor which influnces the drought and flood of Middle and Lower Yangtze Valleys in summer.It is also found that in the flood years,the subtropical anticyclone in the North Pacific is situated in a position in southwest in comparison with that in the drought years, and the cross equatorial flow appears later than that in the drought years.But the appreciable differences are found in spring and summer.Therefore, the persistent circulation characteristics are the important indices for forecasting drought and flood in the Middle and Lower Yangtze Valleys in summer.