The climatic characteristics of summer convection over the Tibetan Plateau revealed by geostationary satellite

Based on the infrared TBB of the geostationary meteorological satellite FY-2E from 2010 to 2014, the climatic characteristics of summer convection over the Tibetan Plateau and its surrounding areas are analyzed. The analysis shows that in May, the main convection occurs in the eastern edge of the Tibetan Plateau. In June, following the onset of the Asian summer monsoon, the strongest convection (severe convection) occurs in the southeastern part of the Tibetan Plateau. In late summer, strong southwesterly winds transport abundant moisture to the eastern and central areas of the Tibetan Plateau, leading to the formation of an active convection belt in the southeastern part of the Tibetan Plateau. In the western plateau, the area with convection frequency greater than 6% reaches the southern plateau at about the 37th pentad, and gradually moves northward until the end of July. In the central plateau, convection (severe convection) becomes active since early (mid) June, and maintains over the entire late summer with three major northward movements until reaching 34°N. Convection in the eastern part of the Tibetan Plateau is relatively active since the beginning of May and its northward stretching time is slightly later than that over the central plateau. Two high intra-seasonal variability centers are located in the middle branch of the Brahmaputra and the southeastern part of the plateau. Summer convective activities are unevenly distributed in these regions, which are prone to drought and flood disasters. The first leading mode of the convection frequency is the reverse mode of that in the Indian monsoon region and the southeastern part of the plateau while the second leading mode reflects the tripole variation pattern over the western part of the plateau, the India continent west of 80°E and the South Asian continent east of 80°E.