The Cloud Physical Parameters Are Retrieved By Using Satellite Data And Their Applications In Weather Modification

The application of satellite data in weather modification mainly is by means of the form of observed picture due to the lack of the product for quantitive study of the cloud, especially of the retrieve of the height, temperature of cloud top, the effective radius and so on. Therefore, the applied effect of satellite data is usually limited.In this paper, according to the pattern of SBDART radiation transmission The relations between the height, temperature of cloud top, the effective radius and the bright temperature of the two infrared channels were gotten by Mao Jietai and Li Juan. And using iterative method of repetitive employ of radiation model , we improved the ways of retrieve and put forward a new way of the combination of multi-station immediate time observation and the data of the 1 and 2 infrared channels to retrieve the height, temperature of cloud top and the effective radius. This indicates that the improved method, having introduced the immediate time soundings, will improve the accuracy of the retrieve.In order to solve the problem of cloud identification in the calculation of retrieve, this paper makes use of the margin between the temperature of the earth and the bright temperature of the cloud top, thus realizes the comprehensive method of using satellite data, ground observation sounding observation and geographic data in identifying cloud. Through the statistic analysis of the data of the period between July and December of the year of 2005, we found that in the cloudless conditions the average margin between the ground temperature and the bright temperature of cloud top was 5.039385℃, which might change daily, thus should get the range according different time to identify cloud, which is proven valid through analysis. Through contrast analysis of case study, the following features of this cloud identification method were concluded: being suited to 24 hours situations;avoiding the influence of geographical features;it is not only consistent with the result of the real observation and the high cloud area, but also accorded with the distribution of the low cloud area.Through contrasting the result of the retrieve about multi-cases with the RHI echo of radar and the accumulated precipitation at the meteorological station, it has been concluded that the height of the retrieve cloud top near the radar station often is slightly higher than the top of radar echo, and with increasing distance to the radar station the difference will increase accordingly. As for relativing stable layer-shaped cloud precipitation, the effective radius of the cloud particle is usually 10 urn;as for fluid precipitation and accumulated cloud precipitation, this does not apply, besides which, effective radius with more than lOum is not the sufficiency condition of the precipitation, because there is not rain in this condition in many stations .By analysing the process of a artificial enhancement precipitation, we also discuss satellite retrieve product's operation in artificial enhancement precipitation. The retrieve cloud top temperature, height and cloud atom's effective radius can be used in choosing the best artificial enhancement precipitation area. And in reference to the change of three physical properties of cloud we can examine the effect of artificial enhancement precipitation. This shows the practical values of satellite retrieve in artificial enhancement precipitation.