EISCAT observations of meteors from the sporadic complex
2013 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 434, no 4, 2907-2921 p.Article in journal (Refereed) Published
We report meteor observation with the European Incoherent Scatter Scientific Association (EISCAT) radars obtained during a continuous 24-h period in 2009 December. The period, just after the Geminid meteor shower, was selected to have no strong meteor shower activity to allow a comparison with our previous observations collected during the 2008 Geminid shower. During the 2009 run, we used the very high frequency (VHF) and ultrahigh frequency systems, but most of the results presented here were derived from the VHF data. We discuss the statistical properties of the radar echoes, their Doppler velocity and altitude distributions, their radar cross-section, etc. We concentrate, as in our previous paper, on the population of high-altitude echoes, which we clearly detect, and discuss these specifically. We recognize a few echoes with positive Doppler velocities as produced by meteoroids that presumably entered the atmosphere at similar to grazing incidence angles and were leaving it when detected by radar. We detect meteor echoes with essentially zero Doppler velocity, reported here for the first time, which we interpret as meteoroids moving almost perpendicular to the beam and producing specular reflections off the meteor trail. We discuss meteors detected with tristatic measurements for which we find bunching in azimuth and depression angle that depends on the time of the day. Finally, we report again of the lack of extreme velocity meteors, a fact that weakens significantly the claim of the existence and abundance of interstellar meteors.
Place, publisher, year, edition, pages
Oxford University Press, 2013. Vol. 434, no 4, 2907-2921 p.
techniques: radar astronomy, meteorites, meteors, meteoroids
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:umu:diva-83919DOI: 10.1093/mnras/stt1199ISI: 000325262300016OAI: oai:DiVA.org:umu-83919DiVA: diva2:678024
FunderSwedish Research Council