Diurnal Variations of Presummer Rainfall over Southern China

• DOI: 10.1175/jcli-d-15-0666.1
• Publication Date: 2016-10-20T16:16:57Z
• Authors: Zhina Jiang; Da-Lin Zhang; Rudi Xia; Tingting Qian
• Keywords: Madden–Julian oscillation

Abstract In this study, the presummer diurnal cycle of rainfall (DCR) over southern China is examined using merged 0.1°-resolution gridded hourly rain gauge and satellite dataset National Centers for Environmental Prediction Final Global Analysis during April to June 2008–2015. Results show pronounced variations in amount, frequency, intensity China, with substantially different amplitudes from southwestern southeastern pre- postmonsoon-onset period. Southwestern often encounters significant nocturnal-to-morning under influence enhanced nocturnal low-level southwesterly winds. Southeastern dominated by afternoon rainfall, as a result surface heating, likely aided local topographical lifting. Both periods exhibit two peaks: one early morning other late afternoon. But latter shows peaks nearly equal amplitude whereas former displays much larger peak than that Three propagating modes accounting DCR are found: (i) an eastward- or southeastward-propagating mode occurs mostly associated transport warm moist air tropical origin induced convergence, (ii) quasi-stationary appears locally sector weak-gradient flows, (iii) inland-propagating daytime association sea breezes along coastal regions, especially evident throughout