Case Analysis on Microphysical Characteristics of Stratiform Cloud Under Synoptic Systems
Two cases of stratiform cloud precipitation in Jilin Province under the upper level trough process on 15 May and the cold vortex on 28 May 2007 are analysed. The microphysical data are sampled with the airborne PMS probes and a hygrothermoscope. It is found that the vertical distribution of particle number concentration, liquid water content, mean diameter of FSSP 100, 2D C and 2D P probes under upper level trough on 15 May are not uniform and the maximum liquid water content is in 0℃ layer. In As Sc under cold vortex on 28 May, the maximum particle number concentration of FSSP 100 in Sc and As are both 350 cm-3; the maximum LWC in As is one ordering more than in Sc and mean diameter in As is far more than in Sc. The particle number concentration and liquid water content of 2D C and 2D P in As are symmetrical, but teeny in Sc because of a dry layer between layers. The layer averaged size distributions of small cloud particles in cloud of 2 cases are quite different. The seedability of cloud is studied. The result shows that the seedability of As clouds under upper level trough is highly seedable clouds, the seedable clouds of As Sc cloud system under cold vortex are 1/2 highly seedable clouds.