Thunderstorm Feature Dataset and Characteristics of Thunderstorm Activities in China

A thunderstorm feature dataset (TFD) is built up based on the black body temperature (TBB) product and cloud classification (CLC) product of FY-2E meteorological satellite as well as the lightning data of the World-Wide Lightning Location Network (WWLLN). In the TFD, thunderstorm cloud is determined when there is WWLLN lightning in the area with TBB not higher than -32℃ or its fitted ellipse. The characteristic parameters of thunderstorms including time, location, morphology, structure, and lightning activities are obtained to establish the TFD. Based on the dataset, thunderstorms in the land of China and the adjacent seas are analyzed after the quality control.The results show that South China, Southwest China, Eastern and Central of Tibetan Plateau and South China Sea are the areas with most frequent thunderstorm activities. North China and Northeast China are two areas with relatively frequent thunderstorm activities in the north part of China. Meanwhile, thunderstorm activity is the weakest in Northwest China.The seasonal variation of thunderstorm activity shows obvious differences between land and sea. The active stage of thunderstorms on land is from June to August. In high latitudes, the peak appears earlier. There is a peak of thunderstorm activity in the South China Sea around May, and another peak after August. The lower the latitude is, the later the second peak appears. The peak time of thunderstorm activity in diurnal variation in most parts of the land is from 1400 BT to 2000 BT and the peak of thunderstorm activity in adjacent sea areas mainly occurs in the morning. In the Sichuan Basin, thunderstorms are more frequent in the early morning. The diurnal variation of thunderstorm activity in the South China Sea is relatively weak.The area of thunderstorm cloud with TBB not higher than -32℃ follows a log-normal distribution, with the peak interval being 1×10³-1×10⁴ km², and the average area is 3.0×10⁴ km². The area of thunderstorm cloud over the sea is obviously larger than that of land, and the South China Sea has the largest area of thunderstorm clouds. On the land, the area of thunderstorm clouds in the east is larger than that in the west, and the average area of thunderstorm clouds greater than 1.2×10⁵ km² can be predominantly found in the first step of Chinese topography. Meanwhile, there is a local center with an average area of thunderstorm clouds greater than 1.2×10⁵ km² in the Qaidam Basin.