Thunderstorm Activity over the Qinghai–Tibet Plateau Indicated by the Combined Data of the FY-2E Geostationary Satellite and WWLLN

Abstract

Thunderstorm activity over the Qinghai–Tibet Plateau (QTP) has important climatic effects and disaster impacts. Using the thunderstorm feature dataset (TFD) established based on the black body temperature (TBB) and cloud classification (CLC) products of the Fengyun-2E (FY-2E) geostationary satellite, as well as the lightning data of the World Wide Lightning Location Network (WWLLN), the temporal and spatial distributions and some cloud properties of the thunderstorms over the QTP were analyzed. Approximately 93.9% and 82.7% of thunderstorms over the QTP occur from May to September and from 12 to 21 o’clock local time, and the corresponding peaks are in August and at 14:00, respectively. There are three centers featuring frequent thunderstorms in the southeast, south-central, and southwest regions of the QTP. The average thunderstorm cloud area (the region with TBB ≤ −32 °C) is 1.8 × 104 km2. Approximately 32.9% of thunderstorms have strong convective cells (SCCs) composed of areas with TBB ≤ −52 °C. The average number and area ratio of SCCs are 3.6 and 25.4%, respectively, and their spatial distribution is given. The average cloud area and the number and area ratio of SCCs of extreme-lightning thunderstorms (thunderstorms with the top 10% of lightning numbers) are approximately 30.0, 3.9, and 1.5 times those of normal thunderstorms. The spatial distribution of the thunderstorm activity is quite different from that of lightning activity given by the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) over the northeastern and southwestern QTP, which may mean that the convection intensity, cloud structure, and charge structure of the thunderstorms over the QTP are different between different regions and seasons.

Spatiotemporal Distributions of the Thunderstorm and Lightning Structures over the Qinghai–Tibet Plateau

“…al. [23] and Ma and Zheng [24] both identified abnormal thunderstorm samples characterized by a relatively large area but a relatively low frequency of flashes, predominantly correlating with thunderstorms in cold seasons. On the other hand, the variation pattern of A>30dBZ suggests the sensitivity of 30 dBZ reflectivity to convective enhancement over the QTP.…”

“…Conversely, thunderstorms in the latter period are more likely to occur under favorable circulation conditions, potentially exhibiting a larger horizontal extension but a weaker lightning yield. During their data control processes, Du et al [23] and Ma and Zheng [24] both identified abnormal thunderstorm samples characterized by a relatively large area but a relatively low frequency of flashes, predominantly correlating with thunderstorms in cold seasons. On the other hand, the variation pattern of A >30dBZ suggests the sensitivity of 30 dBZ reflectivity to convective enhancement over the QTP.…”

“…Some studies have explored the spatiotemporal distributions of thunderstorm and lightning activity across the QTP. Du et al [23] examined the spatial and temporal patterns of thunderstorm activity on the QTP using the thunderstorm feature dataset established by Ma et al [24]. This dataset was based on black body temperature (TBB) and cloud classification (CLC) products from the Fengyun-2E (FY-2E) geostationary satellite, along with lightning data from the World Wide Lightning Location Network (WWLLN).…”