Study On The Macro And Micro Characteristics Of Cumulus Embedded Stratus In Jilin Province

In this paper, the regular weather observation, satellite pictures, Changchun 713 radarobservation in April-July, 2000-2003 are studied, and the data of the PMS sounding, hotwire liquid, 10×10 middle scale ground rainfall amount station, radar, satellite and regularweather observation are also composite analysed, the results show that:(1) Cumulus embedded stratus is one of the primary precipitation cloud systems duringoperation period in Jilin province, account for 36.6% of the total.(2) Cyclone style comes first in the occurrence of effective system of cumulus embeddedstratus precipitation, cold front style second. The cloud system that produce cumulusembedded stratus is divided into comma-shaped cloud system, shield-shaped cloudsystem, belt-shaped cloud system and vortex cloud system by the shape.(3) There are two kinds of the expression form of cumulus embedded stratus on PPI: one isscattered non-regularly distributed convective cloud in a vast expanse of sheet cloud,the echo intensity of the convective cloud below 40dBz; the other is the mix of a vastexpanse of sheet cloud and convective cloud belt, the echo intensity of convective cloudbelt is about 40-50dBz. The characteristics of cumulus embedded stratus on RHI: thereis a clear non-homogeneity bright band, under the bright band, there are strong echoand individual convective cell.(4) There is clear space distribution non-homogeneity of cumulus embedded stratusprecipitation, there is precipitation significance region in rain region, 4-5 times thansurrounding stable precipitation. The convective cloud precipitation in cumulusembedded stratus has clear time non-continuity, the period of the strong precipitation is1-2 hours.(5) Two times PMS sounding shows that average amount concentration of cloud drops isclose to the sounding result to stratus in Jilin province in the past, but the amountconcentration of ice crystal is obviously higher than 10-20/L sounding result in the past.(6) The cold cloud seeding cloud in cumulus embedded stratus account for 90% of totalcold cloud region.(7) Cumulus embedded stratus vertical accumulating liquid water content is generallyhigher than the vertical accumulating liquid water content 0.1-0.4kg/m~2 of stratus. Inthe different phase of cloud development, vertical accumulating liquid water contenthas a significant change, in the mature phase of cloud development, vertical accumulating liquid water content is the largest, it gradually reduce along with theweakening of cloud. At the same time, vertical accumulating liquid water contentdistribution is not homogeneity. The liquid water content of convective cloud region isthree times than that of stable sheet cloud.