1961—2016年中国昼夜降水变化的时空格局

全球气候变暖背景下中国降水量变化的区域差异显著。基于1961—2016年期间,全国763个观测台站白昼和夜间的降水观测数据,分别从昼夜降水量、降水日数、降水强度以及对总降水量的贡献率等四个方面,解读中国九大流域昼夜降水变化的时空格局。结果表明：① 昼夜降水量变化的流域差异显著,可归纳为四种类型：昼夜同增型、昼夜同减型、昼增夜减型和昼减夜增型。② 流域总降水量变化与昼夜降水量密切相关。淮河流域降水量减少是由白昼降水量（-0.72 mm/a）减少所致,而黄河流域降水量减少则是由夜间降水量（-0.21 mm/a）减少所致。③ 干旱区、半干旱区及半湿润区的流域,昼夜大雨的雨量要高于昼夜暴雨;湿润区的流域,则表现为昼夜暴雨的雨量要高于昼夜大雨,尤其是珠江流域和东南诸河流域。④ 从全国尺度来看,白昼大雨、夜间大雨和暴雨对总降水量的贡献率超过10%,而白昼暴雨的贡献率约10%。湿润区流域昼夜暴雨对总降水量的贡献率高于昼夜大雨对总降水量的贡献率,而干旱区-半干旱区流域则相反。研究结果有助于深化认识全球变暖对区域日降水循环的影响。

Spatial and temporal patterns of daytime and nighttime precipitation in China during 1961-2016

There are significant regional differences in precipitation changes in China under global warming during the past half-century. In this study, based on 763 observation stations daytime and nighttime precipitation data to examine the precipitation amounts, precipitation frequency, precipitation intensity, and contribution of daytime and nighttime precipitation to the total precipitation, then to appreciate the spatial and temporal patterns of daytime and nighttime precipitation in China from 1961 to 2016. Results indicated that: (1) There are significant differences between nine river basins of daytime and nighttime precipitation. And the changes patterns can be summarized into four types: daytime and nighttime co-increasing, daytime and nighttime co-decreasing, daytime increasing and nighttime decreasing, and daytime decreasing and nighttime increasing. (2) The change of the total precipitation is closely related to the day and night precipitation. The decrease in daily precipitation in the Huaihe River Basin is due to daytime precipitation decrease (-0.72 mm/a), while the decrease in precipitation in the middle and upper reaches of the Yangtze River Basin is due to the nighttime precipitation decrease (-0.21 mm/a). (3) Daytime and nighttime heavy rain amount is higher than torrential rain in the arid, semi-arid, and semi-humid regions, but in the humid river basin, the torrential rain amount is higher than heavy rain, especially the Pearl River Basin and Southeast River Basins. (4) The contribution of daytime heavy rain, nighttime heavy rain and torrential rain to annual total precipitation exceeds 10%, while the contribution of daytime torrential rain to annual total precipitation is roughly 10%. At the same time, the contribution of daytime and nighttime torrential rain to the annual precipitation is higher than that of daytime and nighttime heavy rain in the humid river basins, while the arid and semi-arid regions demonstrate the opposite. Therefore, the results are helpful to understanding of the impacts of global warming on regional daily precipitation cycles in China.