Spatiotemporal Lightning Activity Detected by WWLLN over the Tibetan Plateau and Its Comparison with LIS Lightning

Abstract

Herein, we compared data on the spatiotemporal distribution of lightning activity obtained from the World Wide Lightning Location Network (WWLLN) with that from the Lightning Imaging Sensor (LIS). The WWLLN and LIS both suggest intense lightning activity over the central and southeastern Tibetan Plateau (TP) during May–September. Meanwhile, the WWLLN indicates relatively weak lightning activity over the northeastern TP, where the LIS suggests very intense lightning activity, and it also indicates a high-density lightning center over the southwestern TP, not suggested by the LIS. Furthermore, the WWLLN lightning peaks in August in terms of monthly variation and in late August in terms of ten-day variation, unlike the corresponding LIS lightning peaks of July and late June, respectively. Other observation data were also introduced into the comparison. The black body temperature (TBB) data from the Fengyun-2E geostationary satellite (as a proxy of deep convection) and thunderstorm day data support the spatial distribution of the WWLLN lightning more. Meanwhile, for seasonal variation, the TBB data is more analogous to the LIS data, while the cloud-to-ground (CG) lightning data from a local CG lightning location system is closer to the WWLLN data. It is speculated that the different WWLLN and LIS observation modes may cause their data to represent different dominant types of lightning, thereby leading to differences in the spatiotemporal distributions of their data. The results may further imply that there exist regional differences and seasonal variations in the electrical properties of thunderstorms over the TP.

Significantly Increased Lightning Activity Over the Tibetan Plateau and Its Relation to Thunderstorm Genesis

“…The WWLLN detects strong lightning strokes, which mainly consist of strong CG and very few IC lightning, using the time of group arrival of very low frequency (VLF) radiation from lightning (Rodger et al., 2006). The WWLLN lightning data from 2010 to 2019 are used in this study because the detection efficiency is relatively higher and more uniform over the TP during this period (Holzworth et al., 2021; Ma et al., 2021). To partially remove the bias of lightning trend caused by the changes in the station of WWLLN, detection‐efficiency‐adjusted WWLLN data were used in the study.…”

Lightning Stroke Strength and Its Correlation with Cloud Macro- and Microphysics over the Tibetan Plateau

“…The average location accuracy of the WWLLN over the TP was ~10 km [57]. Over the midsouthern TP, the DE for CG and total flash were, respectively, 9.37% and 2.58% during 2013-2015 and continuously increased after 2015 [57,58]. Fan et al [57] also found that the CG flash data made up 71.98% of all the WWLLN flash data.…”

“…Fan et al [57] also found that the CG flash data made up 71.98% of all the WWLLN flash data. In addition, Ma et al [58] showed that the DE of the WWLLN over the TP is generally even. Therefore, the DE and the CG percentages over the TP are similar to those over the midsouthern TP.…”

“…To avoid the potential misinterpretation of intracloud lightning flashes with a positive peak current lower than 10 kA [57,58,61], strokes with a positive peak current lower than 10 kA were excluded. To reduce the impact of detection errors, only stroke information detected by at least four stations was considered.…”

Comparison of two nationwide lightning location systems and characteristics of could-to-ground lightning in China

“…The main body of Region-IV is the Tibetan Plateau, mainly including Tibet, Qinghai, southern Xinjiang, and western Sichuan. It has a highland mountain climate, and the overall geomorphic distribution trend is increasing from west to east (Ma et al, 2021). The uninhabited areas above 4500 m in elevation in the west and north of Region-IV are icy all year round, covered by snows and glaciers.…”