1995, 21(4):3-7. DOI: 10.7519/j.issn.1000-0526.1995.04.001
Abstract:The advances of the scientific research and operational work of the state-level agrometeorological crop yield prediction of . China were recalled and summarized. Some progress were made in the crop yield sequence separation and prediction,including the- attempt of using crop growth simulation models for crop yield prediction. In operational respect,historical database was expanded and a real-time communication network was established. A new version of software system for crop yield prediction (WAYPS) was developed,and the level of operational service was improved greatly.
1995, 21(4):8-10. DOI: 10.7519/j.issn.1000-0526.1995.4.002
Abstract:The onset and development of ship meteo-routing are introduced in China. With the help of science and technology of weather forecast, navigation, computer and telecommunication, global optimum weather route service can be provided and remarkable social--economic benefit can be achieved.
1995, 21(4):11-15. DOI: 10.7519/j.issn.1000-0526.1995.04.003
Abstract:The change of the turbulent fields during a mesoscale system which occured on August 7,1990 in Tongxian,the suburb of Beijing is analyzed. The results show that during the development of mesoscale system the turbulent parameters in the surface layer changed significantly. The local turbulent transportation accelerates the development of. mesoscale system in some respects, and besides the local turbulent spectra have some obvious variations during the incursion of mesoscale systems.
1995, 21(4):16-21. DOI: 10.7519/j.issn.1000-0526.1995.4.004
Abstract:The concepts and characteristics of fractals and fractal dimension are firstly introduced. And the computation method of fractal dimension of dynamical system from one variable time series X (t) is mainly discussed. The computation technique of FD can be separated into two steps: reconstruction of phase space R (p) from X(t) and computation of relation integral and dimension for approaching to FD.The FD of ENSO is calculated by SST data at some grid points in central and eastern equatorial Pacific during the period from 1951 to 1979. The results show that FD of ENSO is 4. 95. 7 and ENSO is therefore proved to be a complicated chaotic system according to which five or six independent variables are enough to describe. Finally FD of some weather and climatic attractors is given.
1995, 21(4):22-24. DOI: 10.7519/j.issn.1000-0526.1995.4.005
Abstract:The Features of weather/climate in China in 1994 was analyzed. This year,there was more plentiful precipitation in both South China and North China. While the middle part drier. There were two rain belts in North China and South China, respectively. In general,the climate this year is normal or differ from it to a certain extent.
1995, 21(4):25-28. DOI: 10.7519/j.issn.1000-0526.1995.04.006
Abstract:General circulation features over the Northern Hemisphere in 1994 are analysed. It is shown that the subtropical high over the west Pacific is stronger than normal and extends to the west,in mid-summer it moves northward abnormally. Zonal circtilation is dominant in Eurasian 9 and Polar vortex in the Northern Hemisphere is smaller in area and weaker in strength than normal. In midlatitude of the East Asia,high pressure systems keep stable in summer,and frontal zone in westerly moves northward. At 100hpa, the South Asia high is stronger in strength, further to the north and eastward than normal. A new El Nino event is forming over the tropical Pacific. The anormaly of both the atomspheric circulation and the tropical ocean exerts a significant impact on the weather and climate in China.
1995, 21(4):29-32. DOI: 10.7519/j.issn.1000-0526.1995.4.007
Abstract:The world climate in 1994 is reviewed. Analysis shows that the world climate in 1994 wasgenerally warmer than normal. Particularly,in July-August the large sections of the middle latitudes in the Northern Hemisphere were hit by heat wave. Many regions experienced exceptional hot and rainless conditions. Meanwhile,the extrem climate events such as severe drought or serious flood freguently occurred in some areas of the world. In Australia and the indonesia the persistent droughts were still in association with the ENSO events since 1991.
1995, 21(4):33-36. DOI: 10.7519/j.issn.1000-0526.1995.04.008
Abstract:A few signs of occurrence and development of rneso-scale cloud cluster accompanied by heavy rainfall during midsummer afternoon over Beijing area had been found by the use of the moist available energy method. They are as follows :a) a lot of moist available energy was already stored up over Beijing area;b) the moist available energy is being accumulated over Beijing area; c) the flow pattern in the lower troposphere is favourable for the occurrence of the forced lifting;d) there will be a larger temperature contrast,which results from diabatic heating process,in the area between Beijing area and the bend of the Yellow River in the afternoon.
1995, 21(4):37-42. DOI: 10.7519/j.issn.1000-0526.1995.4.009
Abstract:The general situation and used technical principle in operational system of the air force limited-area short-term numerical forecast are introduced. The result of verification is compared with that of the internal system of the some kind. The result of a case study is also gived.
1995, 21(4):43-45. DOI: 10.7519/j.issn.1000-0526.1995.04.010
Abstract:Based on the summation of vocational effect of MOS prediction at weather stations of Jiangsu province in recent 10 years,the applied value of model B at provincial weather,tations are exposed. It includes the explanatory level and experience of the weather in Jiangsu and the way how to obtain the maximum forecasting effect.
1995, 21(4):46-49. DOI: 10.7519/j.issn.1000-0526.1995.04.011
Abstract:The methods of applying .NOAA-AVHRR data to make water area are discussed. The water area are identified by NDVI made of CHI and CH2,and the way of applying fuzzy mathematics to make water area of the mixed. pixel are put forward.
1995, 21(4):50-53. DOI: 10.7519/j.issn.1000-0526.1995.4.012
Abstract:According to principles of integral regression,a dynamic statistical model is developed for the effects of climatic change on crop yield in the time scale of 10 days. The mode opens a new way for agricultural service of climatic influence assessment,because of its continuation and promptness. In order to make the model more suitable for practical use,the following methods are used during its establishment:three term crop yield forecast model,diagnostic analysis for special factors, and choice of best integral regression equation. And satisfactory results are achieved in model test.
1995, 21(4):54-56. DOI: 10.7519/j.issn.1000-0526.1995.4.013
Abstract:In order to combat drought and get bumper harvest,it is an important measure to carry out artificial precipitation enhancement in time based on the drought situation. Agricultural drought has relations not only to rainfall but also to spatial and temporal distribution of precipitationBased on drought criterion,drought index is calculated and is divided into sevenal degrees to show the extent of drought. These characteristic values are then used directly in the operation of artificial precipitation stimulation and obvious effect is obtained

