关键词: 雨滴谱, 对流单体, 催化目标云, 对比云, 增雨率

Abstract:

In order to collect and collate the relevant evidences of artificial precipitation operation for convective clouds, based on the raindrop spectrum of LNM and sounding data in Wuhan station, GPS/MET water vapour data, Doppler radar data and minutely precipitation from atuomatic weather stations, etc, the seeding conditions and developments of convective clouds over Wuhan and surrounding regions from 28 to 29 September 2014 were studied, and then the effect of artificial precipitation operation was analyzed and tested. The results are as follows: (1) The thermodynamic structures with upper dry and lower wet at the middle and low troposphere were conductive to air convection in the atmosphere, and the height of radar echo top was 10 km above with a lot of supercooled water, the seeded clouds were in borning and developing stage, which provided the better seeding conditions. (2) Compared with the contrastive clouds, the physical parameters of the seeding convective cells such as the maximum reflectivity factor, echo top height, vertical integrated liquid water content and strong echo area, etc, appearred an increase in varying degrees after the seeding, and the whole life of the seeding convective cells extended 31 - 72 min, thereinto the seeding F1 cells combined with B0 cells at 00:32 BST 29 September 2014, which passed over Wuhan observatory from 00:33 BST to 00:51 BST 29 September, and the peak of precipitation particles appeared at 1.85 mm of particle sizes, the particle size and number concentration increased rapidly to the maximum. (3) The precipatation of three seeding clouds increased by above 36% compared with the concrastive clouds.

Key words: raindrop spectrum of LNM, convective cells, seeding cloud, contrastive cloud, rate of precipitation enhancement