为了探究2003—2021年中国可降水量时空分布及其变化趋势特点,采用美国国家航空航天局地球观测系统卫星Aqua上AIRS探测仪反演的AIRS3STM中可降水量数据,通过线性拟合、Mann-Kendall检验和经验正交函数分析法,分析其时空变化影响因素。结果表明:①中国日间、夜间年际可降水量呈上升趋势,日间上升速率为0.044 (kg/m²)/a,夜间上升速率为0.062 (kg/m²)/a,并得出日间、夜间突变点发生时间分别是2014年和2008年。②中国日间、夜间四季变化均为上升趋势,夏季变化速率最大,春季、冬季变化速率较低,仅日间夏季和夜间的夏、秋和冬季通过了α=0.05的显著性检验。③中国日间可降水量和地表温度空间分布与纬度呈负相关,纬度越低,可降水量、地表温度越高,华南地区可降水量较高,西北地区偏低,利用EOF分析法选取部分典型区域也验证了以上规律。④可降水量与地表温度呈正相关,地表温度越高,其上升趋势越明显。研究成果对中国的气候、地形分布以及自然灾害预警均有一定参考意义。

The precipitation data from AIRS3STM inverted by AIRS detector on NASA's Aqua satellite was adopted to analyze the spatio-temporal distribution and variations of available precipitation in China from 2003 to 2021. Linear fitting, Mann-Kendall test and empirical orthogonal function analysis were employed to reveal the influencing factors of spatio-temporal change. Results reveal that 1) interannual available precipitation during daytime and nighttime in China has been increasing with daytime rising rate of 0.044 kg·m^-2·a^-1 and nocturnal rising rate of 0.062 kg·m^-2·a^-1. Daytime mutation point occurred in 2014 while nocturnal mutation point occurred in 2008. 2) Changes in all four seasons during day and night show upward trends with summer change rate being highest while change rate in spring and winter is low. Only changes in summer daytime, summer, autumn and winter nighttime passed significance test of α=0.05. 3) Spatial distribution of daytime available precipitation and surface temperature in China is negatively correlated with latitude. Lower latitude sees higher available precipitation and surface temperature. South China has larger available precipitation than northwest China. EOF analysis on some typical areas also verifies this law. 4) Amount of available precipitation is positively correlated with surface temperature and such trend grows more obvious with higher surface temperature.