Diurnal cycle of precipitation over Fujian Province during the pre-summer rainy season in southern China.

Precipitation diurnal cycle over Fujian in the pre-summer rainy season has been revealed based on the hourly rain gauge data during 2009-2013. The precipitation amount (PA) over northwestern Fujian and most southeast coasts shows relatively small diurnal variability. This is in contrast to large diurnal variations in the mountainous areas. Regional differences in precipitation diurnal cycles are obviously noted among the coastal, valley, hilly, and mountainous areas. The precipitation diurnal cycles are significantly affected by the terrain elevation and distance to coast, PA and precipitation frequency (PF) show much more pronounced double diurnal peaks with the terrain elevation and distance to coast increased. However, the precipitation intensity (PI) basically shows one distinct late afternoon diurnal peak for different elevations and distances to coast. Four typical patterns of precipitation diurnal cycle are further identified by cluster analysis. The four typical PF patterns show relatively apparent morning peaks over coasts, inland mountains, and hills in addition to distinct late afternoon maxima. Low PF with weak diurnal amplitude is mainly located over the coastal areas, while high PF with strong diurnal amplitude is found over the valley, hilly, and mountainous regions. The PA exhibits a weak early morning peak and a relatively strong late afternoon peak over coastal, hilly, or mountainous areas and windward slopes but only one distinct late afternoon peak over the valley regions and leeward slopes. The amplitude of PA diurnal cycle is the weakest over the coastal areas but the strongest over the valley regions or leeward slopes among the four PA patterns. The four PI diurnal cycle patterns consistently show distinct afternoon peaks. [ABSTRACT FROM AUTHOR]