Review and prospect of climate characteristics of cloud and precipitation in subtropical high center

Since the subtropical highs are considered to be dominated by downward motion, the researches on the cloud and precipitation in these areas are limited so far. In order to understand the cloud and precipitation features under the subtropical high conditions, this paper reviews and prospects those related studies that are based on the satellite remote sensing observations. As exposed by previous studies, the total cloud amounts within the subtropical highs can reach over 30%. In summer, the subtropical high is dominated by stratocumulus clouds (14.92%), followed by cirrus (12.13%), and then altostratus and cirrostratus (less than 5%). Additionally, the cloud shortwave radiation forcing heats earth-atmosphere system by 82.19 W·m^-2, while the long-wave radiation forcing cools the system by 22.28 W·m^-2. Furthermore, there are upward motions and precipitation in the subtropical high center for all four seasons. For the western Pacific subtropical high, the daily mean rainfall reaches 1.5 mm/d during winter and spring seasons and 2 mm/d in summer. From south of the North America via Atlantic to North Africa, the daily rainfall in these subtropical highs reaches over 3 mm/d, with approaching or exceeding 50% of the contribution to local rainfall. Moreover, there is a quasi-linear relationship between the frequencies of precipitation and the upward movement in the subtropical high. These results indicate that more thorough studies of the cloud and precipitation processes in the subtropical high are needed to understand the characteristics and thermodynamic mechanisms of subtropical high.