A comparative study of cloud-precipitation microphysical properties between East Asia and other regions

Abstract

A database is established that includes microphysical properties of raindrops, cloud droplets, ice nuclei (IN), snow crystals, and the relationship between radar reflectivity (Z) and rainfall rate (R), based on the in situ data reported in the existing literature. The data coverage is divided into East Asia and the other regions (Americas, Europe, Australia, and Africa), and only the datasets obtained over land are considered. The main properties of microphysical variables over East Asia are presented and compared with those over the other regions. The main differences of the properties between those two regions are as follows. The average intercept (N0) of exponential-size distributions is much smaller over East Asia than that over the other regions and slope (Λ) is slightly smaller. As for gamma-size distributions, the overall average value of intercept is much smaller over East Asia, and the range of parameters is narrower in East Asia compared with the other regions. In addition, most of the shape parameter γ are negative over East Asia, whereas positive γ appears frequently in the other regions. Compared with the other regions, the average cloud droplet concentration is much smaller in stratiform clouds over East Asia, and cloud liquid water content in East Asia is 0.114 gm-3 lower. There is a higher total mean IN concentration of 20.2 L-1 in East Asia, whereas it is 2.7 L-1 in theother regions. Compared with the other regions, the average N0 for snow-crystal-sizedistributions over East Asia is much smaller and Λ is less than half of that. The Z-R relation shows that the average Z is larger in East Asia than that in the other regions for rains originating from convective clouds with the same R, whereas the average Z is slightly smaller in East Asia for rains originating from stratiform clouds. © 2013, Meteorological Society of Japan.