Abstract:Three seperated (but coincident in time) field experiments on tropical cyclones in the western North Pacific will be carried by the members of the Typhoon Committee, the USA and the USSR, respectively, during August-September 1990. Here is the summary on the objectives, observational network and instruments, and data collection of the experiments.

Abstract:The Technique of Determining Tropical Cyclone Intensity in NMC is improved according to analyses of EIR imageries (1983-1988). In the determination of the cloud index for tropical cyclone intensity, some factors are incorporated, (a) the temperature and diameter of the eye area, (b) the lowest cloud-top temperature of CDO, (c) the lowest cloud -top temperature of spiral cloud band. The relationship between cloud intensity indices and maximum wind velocity near the center of tropical cyclone is also derived from curve fitting. The new technique is more objective and quantitative than anyone before.

Abstract:This paper presents with some results from analyses which show that the arrays of the OLR anomaly pattern might enter the opposite appearances between the drought and flood cases over the Changjiang River Basins. When the negative (positive) OLR anomaly region appeared over the west tropical Pacific with drought/Hood events, the positive (negative) OLR region might be over the equatorial central Pacific. And the most significant difference occured over the equatoral central Paific.The multi-spectral analysis shows that the processes of OLR over the equacoral central Pacific affected on the drought/flood over the Changji-ang River Basins seem to be the westerly propagations.

Abstract:Based on the analysis of the variation and character of major distribution of the drought/flood along the reaches of the Changjiang River, the principal components of characteristic vector arc regarded MS,the drought/flood index. The trend prediction model is built using a new modelling scheme.