WWLLN Datasets for "A Terrestrial Gamma-ray Flash from the 2022 Hunga Tonga–Hunga Ha'apai Volcanic Eruption"

These data files contain data used in the paper "A Terrestrial Gamma-ray Flash from the 2022 Hunga Tonga–Hunga Ha’apai Volcanic Eruption", M. S. Briggs, S. Lesage, C. Schultz, B. Mailyan, R. H. Holzworth, Geophysical Research Letters, 2022.

The authors wish to thank the World Wide Lightning Location Network (WWLLN), a collaboration among over 50 universities and institutions, for providing the lightning location data used in these datasets and in the paper. Additional WWLLN data are available at nominal cost from http://wwlln.net.

The file named Fig_1.txt contains the data used to generate Figure 1 in the paper.

The first two columns list the time ranges for each histogram bin, in UTC on 2022 January 15, while the final column lists the lightning detection rate, in counts per minute, for all WWLLN sferics located within a 400 km radius of the Hunga Tonga–Hunga Ha’apai volcano.

The times when Fermi passed within 1000 km of the volcano, shown as grey bars in Figure 1, are:
03:47:58.5 to 03:52:56.2 UTC
05:29:25.1 to 05:33:59.7 UTC
07:11:04.0 to 07:15:18.3 UTC
08:52:04.8 to 08:57:05.1 UTC
10:33:48.1 to 10:37:32.7 UTC

The time of the Fermi TGF detection, shown as a red line in Figure 1, is:
08:52:40.011500 UTC

The file named Fig_2.txt contains the WWLLN sferic data used to generate Figure 2 in the aforementioned paper.

This file has the same format as the text files for the WWLLN maps provided in the Fermi GBM TGF catalog, https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/tgf/.

Line 1 is the network_name
Line 2 is TGF_name
Line 3 is the coordinates of Fermi at the time of the TGF (2022-01-15 08:52:40.011500 UTC).
Line 4 is the coordinates of the center of the map
The second number on line 5 is the number of sferics in a +/- 1 minute interval about the TGF.
The remaining 104 lines list the properties of each sferic in columns containing the following information:
sequence_number, longitude, latitude, time_separation_between_sferic_and_TGF_corrected_for_light-travel-time

The two GLM lightning flashes, shown as magenta dots in Figure 2, have longitude and latitude values:
-175.27394, -20.9348
-175.29301, -20.8466

All of the aforementioned longitudes are East longitudes.