Attenuation of lightning‐produced sferics in the Earth‐ionosphere waveguide and low‐latitude ionosphere

Abstract

[1] We compare radio atmospherics (sferics) detected by the World Wide Lightning Location Network (WWLLN) to very low frequency (VLF) whistler waves observed in the low-latitude ionosphere by the Vector Electric Field Instrument of the Communications/Navigation Outage Forecasting System (C/NOFS) satellite. We also model the propagation of these sferics through the Earth-ionosphere waveguide to the subsatellite point using the Long-Wavelength Propagation Capability software and compare this result to the same C/NOFS data set. This unprecedentedly expansive data set allows comparison to theory and prior observation of VLF radio wave propagation in the Earth-ionosphere waveguide and low-latitude ionosphere. We show that WWLLN and C/NOFS observe the well-known effect of variable attenuation with direction within the Earth-ionosphere waveguide. Propagation within the ionosphere is also examined, and a lack of attenuation above 400 km is observed. Finally, in comparison to recent works using Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) data by Fiser et al. and Chum et al., we find that C/NOFS successfully detects whistlers with comparable amplitudes at much greater distances, compared to those reported for DEMETER.

Coordinated Satellite Observations of the Very Low Frequency Transmission Through the Ionospheric D Layer at Low Latitudes, Using Broadband Radio Emissions From Lightning

“…The magnetic propagation azimuth of arrival at the subsatellite point (of the great circle path to the area of the subsatellite point) affects both the waveguide attenuation (Hutchins et al, ) and the efficiency of upward coupling to magnetospheric whistlers (Jacobson et al, ). C/NOFS and VEFI data have already been used at least to identify azimuth sensitivity of this sort (Burkholder et al, ). This dependence on azimuth is due to the anisotropic dielectric properties of a magnetized plasma.…”

Analysis of Electric and Magnetic Lightning‐Generated Wave Amplitudes Measured by the Van Allen Probes

“…Analysis of LGW occurrence, power, and/or effects in space is often supported by lightning databases established from ground VLF stations. For instance, Peter and Inan (2005) use the U.S. National Lightning Detection Network (Cummins et al, 1998) and Burkholder et al (2013), Zheng et al (2016), Jacobson et al (2018), Ripoll, Farges, et al (2019), and Záhlava et al, 2019 use the World Wide Lightning Location Network (WWLLN) (e.g., Hutchins, Holzworth, Brundell, & Rodger, 2012 ; Hutchins, Holzworth, Rodger, & Brundell, 2012 ; Holzworth et al, 2011; Rodger et al, 2009). Colman and Starks (2013) use optical spaceborne cameras such as the Optical Transient Detector and its follow‐on the Lightning Imaging Sensor (e.g., Cecil , 2001 ; Cecil et al, 2014 ; Christian et al, 2003).…”

Local and Statistical Maps of Lightning‐Generated Wave Power Density Estimated at the Van Allen Probes Footprints From the World‐Wide Lightning Location Network Database

“…We use a model for propagating the WWLLN‐detected lightning events from 2012 to 2016 to the Van Allen Probes (RBSP; Mauk et al, ) footprints of all field lines that constitute an electron's drift shell. We assume that a lightning discharge is an emitting antenna and that the wave signal follows an attenuation law derived empirically from C/NOFS observations (Burkholder et al, ) as it travels from its source to the observing sensor at the satellite footprint and further assume that the LGW power density at the footprint maps to the LGW wave intensity at the equator identically for all field lines in the drift shell. Thus, the ratio R WWLLN = P d / P l of the drift equatorial LGW power density P d to the equatorial LGW power density on a given field line P l can be computed.…”