Session CD4 - Recent advances in VLF observations of the ionosphere during space weather events

Carine Briand, onsite (LESIA, Observatoire de Paris-PSL), Mark Clilverd (British Antarctic Survey), Peter Gallagher (Dublin Institute for Advanced Studies)

Solar eruptions are the source of significant disturbances of the ionosphere through the rapid increase in energetic radiation, particularly the X-ray flux. Radio wave propagation effects and increases in D- and E-region electron density are the main perturbations generated by these events. From the space weather point of view, HF blackouts over extended regions are the major risks linked to solar eruptions. Being too high for balloons and too low for in situ measurements with spacecraft, the lower ionospheric D-layer, a key region of absorption of the HF emission, is mostly surveyed by VLF measurements. Networks of VLF receivers have been deployed by various groups, including the polar regions (AARDDVARK), Latin and South America (LATNET & SAVNET) or spread over the world (SUPERSID & AWESOME). VLF measurements have also proved to be a powerful tool to detect transients linked to thunderstorm regions (Elves, Sprites, and Terrestrial Gamma-ray Flashes). The interest in such events was recently raised for civil aviation since they can be the source of intense ionizing radiations. This session aims to present several aspects of recent achievements for solar flares or thunderstorm luminous events, from instrumentation to observations, and also modelling. We will also discuss the buildup of an international organization to better share and analyze the VLF data during specific space weather events.

Poster Viewing
Thursday October 27, 08:30 - 13:30, Poster Area

Thursday October 27, 16:30 - 17:45, Earth Hall

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Talks : Time schedule

Thursday October 27, 16:30 - 17:45, Earth Hall
16:30The North American VLF array and polarization observations during space weather eventsMoore, R et al.Oral
16:45Improvements on the GIFDS‘ VLF network and its use for detecting solar flaresHansen, M et al.Oral
17:00Probing geo-storm driven ionospheric irregularities in the upper and lower ionosphereNwankwo, V et al.Oral
17:15Lower-ionosphere Electron Density from Multi-instrument Satellite Observations and Ground VLF Measurements during Solar FlaresZigman , V et al.Oral
17:30Numerical modeling of the solar flare impact on lower ionosphere as monitored by VLF propagation effectsBasak, T et al.Oral


1Filtering the useful flaring information from VLF signal Guerrero, A et al.Poster
2AWESOME@Nancay: performances and first resultsBriand, C et al.Poster
3VLF4IONS: a projet of VLF receivers around the equatorial regionBriand, C et al.Poster
4Detection of Solar Flares from the Analysis of Signal-To-Noise Ratio Records from the Ebro ObservatorySegarra, A et al.Poster
5Study of the response of the lower ionosphere to solar-induced X-Ray using VLF data from A118 (France) and Anchor University Space Lab (Nigeria) receiversOvie, O et al.Poster
6Analysis of VLF disturbances using spectral methods and information entropy and perspectives of multiparameter ULF, VLF and HF Space Weather monitoringRapoport, Y et al.Poster