Evaluation of Detection Efficiency of World Wide Lightning Location Network in Southeast Asian Region

Abstract

The detection efficiency (DE) of the World Wide Lightning Location Network (WWLLN) is evaluated in Southeast Asia by comparing WWLLN data with the Earth Network Total Lightning Network (ENTLN) data taking into account time, distance, and peak‐current parameters. The performance of WWLLN is evaluated in the months of November and December in two different years (2020–2021). These periods are selected to assess the change (if any) in DE overtime and the inclusion of new stations. The strokes between the two networks were considered matched if they fell within a time criterion of 100 µs and a location difference of 25 km. Using this criterion, 5.2 × 106 WWLLN strokes were matched with ENTLN cloud‐to‐ground (CG) lightning strokes in November‐December 2020, resulting in a DE of 32.9%. Similarly, 4.6 × 106 WWLLN strokes were found to match in November‐December 2021, yielding a DE of 36.5%. Analysis of the peak‐currents reveals that DE is lowest (<10%) for a peak‐current below ±10 kA. However, for peak‐current exceeding ±50 kA, the DE increases to ∼60%. During November‐December 2021, WWLLN reported 38.95 × 106 lightning strokes globally; amongst them, Dhaka station detected 0.5 × 106 strokes, contributing to a 1.3% increase in the global DE. Dhaka station detects most lightning strokes within 8 × 103 km, which diminishes to zero after 10 × 103 km. The Dhaka station recorded a larger number of strokes at longer detection distances during midnight (22:00–02:00) than during noon (10:00–14:00). The results signify a positive impact of the Dhaka station on WWLLN's DE during the mentioned period.