Spatiotemporal Variations in Daytime and Night-Time Precipitation on the Yunnan–Guizhou Plateau from 1960 to 2017

Abstract

Spatial and temporal variations in daytime and night-time precipitation and differences in these variations between the dry and wet seasons were investigated based on a daily precipitation dataset comprising data from 73 meteorological stations on the Yunnan–Guizhou Plateau from 1960 to 2017. The results show that both daytime and night-time precipitation and the numbers of daytime and night-time precipitation days exhibited nonsignificant downward trends over a long timescale but fluctuated on an interdecadal scale. A complicated relationship was found between elevation and precipitation because the vertical precipitation gradient first increased with elevation and then decreased with elevation when the elevation exceeded 1500 m. Additionally, the average annual precipitation was clearly greater at night-time than in the daytime during the corresponding period. Furthermore, heavy and moderate rainfall contributed more than half of the total annual precipitation, and several rainfall days contributed much of the annual precipitation, particularly at night; night-time precipitation produced 33% of the average annual precipitation on only 5% of annual rainfall days. Additionally, we found significant correlation between El Niño–Southern Oscillation (ENSO) indexes and precipitation. These findings are valuable for coping with meteorological disasters associated with extreme precipitation under global climate change.