A study of cloud vertical profiles from the Cloudsat data over the East Asian Continent

The Cloudsat satellite data during June 2006 to April 2011,were used to investigate the cloud vertical profiles over the East Asian region (20°-50°N, 80°-120°E),with particular emphasis on comparing the differences between radar reflectivity profiles of precipitation and non-precipitation clouds, as well as seasonal variations of these profiles. The results show that: (1)Ucnerally, the radar reflectivity of precipitation clouds mainly locates at below 8 km with dBz between -20 and 15,while the radar reflectivity of non-precipitation clouds locates at 4-12 km with dBz between -28-0 with the radar reflectivity of precipitation being able to usually reach to ground;(2) there are differences among liquid precipitation,solid precipitation, and possible drizzle precipitation clouds profiles;(3) the radar reflectivity increases gradually from 11 km to 7 km with the temperatures always below 0℃ in liquid precipitation clouds,suggesting that condensation and collision-coalescence processes play a vital role in the formation of large-size liquid drops;(4) the frequency distribution of temperature at -15℃ is consistent with the high radar reflectivity in solid precipitation clouds, meaning that the temperature at -15℃ or so is advantageous to deposition and accretion processes; (5) the vertical distribution of liquid precipitation clouds changes slightly from spring to autumn, but mainly in the low-level in winter; the vertical distribution of solid precipitation clouds changes with alternate double and single high-frequency with the season,and this is consistent with the variation of the frequency distribution of temperature at -15℃;the non-precipitation clouds vertical distribution changes little with season;and (6) the deep connective and nimbostratus clouds are the major types of cloud generating precipitation drops.