A Three Year Sample of Almost 1600 Elves Recorded Above South America by the Pierre Auger Cosmic Ray Observatory

THE PIERRE AUGER COLLABORATION; GARCIA, B (COMO PARTE DE THE PIERRE AUGER COLLABORATION)

Earth and Space Science

Wiley

Año: 2020 p. 1 - 17

2333-5084

Elvesare a class of transient luminous events, with a radial extenttypically greater than 250 km, that occur in the lower ionosphereabove strong electrical storms. We report the observation of1,598elves, from 2014 to 2016, recorded with unprecedented time resolution(100 ns) using the fluorescence detector (FD) of the Pierre AugerCosmic-Ray Observatory. The Auger Observatory is locatedinthe Mendoza province of Argentina with a viewing footprint for elveobservations of 3 · 106km2,reaching areas above the Pacific and Atlantic Oceans, as well as theCórdoba region, which is known forsevereconvective thunderstorms. Primarily designed for ultrahigh energycosmic-ray observations, the Auger FD turns out to be very sensitiveto the ultraviolet emission in elves. The detector features modifiedSchmidt optics with large apertures resulting in a field of view thatspans the horizon, and year-round operation on dark nights with lowmoonlight background, when the local weather is favorable. Themeasured light profiles of 18% of the elve events have more than onepeak, compatible with intracloud activity. Within the 3-year sample,72% of the elves correlate with the far-field radiation measurementsof the World Wide Lightning Location Network. The Auger Observatoryplans to continue operations until at least 2025, including elveobservations and analysis. To the best of our knowledge, thisobservatory is the only facility on Earth that measures elves withyear-round operation and full horizon coveragep { margin-bottom: 0.1in; line-height: 115%; background: transparent }