Characteristics of the Precipitation Diurnal Variation and Underlying Mechanisms Over Jiangsu, Eastern China, During Warm Season

Based on the hourly precipitation observed from ∼1800 automatic rain gauges during 2013–2017, characteristics of diurnal variation and underlying mechanisms over Jiangsu Province, eastern China, warm season (May to September) have been revealed in this study. Results show that amount (PA), frequency (PF), intensity (PI) are zonally distributed Jiangsu. The shows distinct cycle zonal distribution. large is located southwest side section Yangtze River (JSYR). From midnight noon, expands northeastward, but shrinks southeastward noon midnight. Meanwhile, PA larger daytime than nighttime most In addition, two peaks, with one early morning mainly resulting long-duration rainfall other afternoon short-duration rainfall. total largely contributed by During whole season, water vapor convergence (divergence) ascending (sinking) movements consistent, corresponding cycles. contribution long (short) duration areas very sub-seasonal variations a clear decreasing (increasing) trend pre-Meiyu through Meiyu post-Meiyu. Among three subperiods mostly those period. closely related enhancement However, post-Meiyu periods, more consistent dynamic lift since abundant. Concluded cluster analysis, spatial distributions associated surface, such as River, big cities, Lake Taihu, Hongze, complex coastal lines. different surfaces respective features.