TY - JOUR

T1 - Occurrence and Altitude of the Long-Lived Nonspecular Meteor Trails During Meteor Showers at High Latitudes

AU - Kozlovsky, A.

AU - Lukianova, R.

AU - Lester, M.

N1 - Funding Information: R. L. acknowledges support from the Academy of Finland via Grant 322360. M. L. acknowledges support from Science and Technology Facilities Council (STFC) via Grant ST/S000429/1. The authors acknowledge discussions within the International Space Science Institute (ISSI) Team 410 on New Features in the Meteor Radar Observations and Applications for Space Research. Publisher Copyright: ©2020. American Geophysical Union. All Rights Reserved. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/8/1

Y1 - 2020/8/1

N2 - Meteoroids entering the Earth's atmosphere produce ionized trails, which are detectable by radio sounding. Cylindrical underdense (and partly overdense) trails form a great majority of meteor echoes received by meteor radars (MRs). Additionally, the long-lived nonspecular (LLNS) meteor echoes are received from irregularities of ionization generated along tracks of relatively large meteoroids. At high latitudes where the magnetic field is nearly perpendicular to the Earth's surface the LLNS echoes are possible only from non-field-aligned irregularities. The occurrence and height distributions of LLNS echoes are studied using MR observations at the high-latitude Sodankylä Geophysical Observatory (SGO, 67°22′N, 26°38′E, Finland) during 2008–2019. Two parameters are analyzed: the percentage and height distribution of LLNS echoes. These LLNS echoes constitute about 3% of all MR detections. However, during certain meteor showers (i.e., the Geminids, Perseids, Quadrantids, Arietids or/and Daytime ζ-Perseids, and Lyrids) the percentage of LLNS echoes is noticeably higher (about 10%, 8%, 7%, 7%, and 4%, respectively). Typically, the LLNSs occur ∼1–2 km higher than other echoes (in June–July the height difference is reduced to ∼0.5–1 km). Moreover, during the Lyrids, η-Aquariids, Perseids, Orionids, and Leonids the LLNS echoes occur noticeably, up to 3–5 km, higher than the echoes from other types of trails.

AB - Meteoroids entering the Earth's atmosphere produce ionized trails, which are detectable by radio sounding. Cylindrical underdense (and partly overdense) trails form a great majority of meteor echoes received by meteor radars (MRs). Additionally, the long-lived nonspecular (LLNS) meteor echoes are received from irregularities of ionization generated along tracks of relatively large meteoroids. At high latitudes where the magnetic field is nearly perpendicular to the Earth's surface the LLNS echoes are possible only from non-field-aligned irregularities. The occurrence and height distributions of LLNS echoes are studied using MR observations at the high-latitude Sodankylä Geophysical Observatory (SGO, 67°22′N, 26°38′E, Finland) during 2008–2019. Two parameters are analyzed: the percentage and height distribution of LLNS echoes. These LLNS echoes constitute about 3% of all MR detections. However, during certain meteor showers (i.e., the Geminids, Perseids, Quadrantids, Arietids or/and Daytime ζ-Perseids, and Lyrids) the percentage of LLNS echoes is noticeably higher (about 10%, 8%, 7%, 7%, and 4%, respectively). Typically, the LLNSs occur ∼1–2 km higher than other echoes (in June–July the height difference is reduced to ∼0.5–1 km). Moreover, during the Lyrids, η-Aquariids, Perseids, Orionids, and Leonids the LLNS echoes occur noticeably, up to 3–5 km, higher than the echoes from other types of trails.

KW - meteor radar

KW - meteoric dust

KW - meteors

KW - trails of meteors

UR - http://www.scopus.com/inward/record.url?scp=85089887507&partnerID=8YFLogxK

U2 - 10.1029/2019JA027746

DO - 10.1029/2019JA027746

M3 - Article

AN - SCOPUS:85089887507

VL - 125

JO - Journal of Geophysical Research: Biogeosciences

JF - Journal of Geophysical Research: Biogeosciences

SN - 0148-0227

IS - 8

M1 - e2019JA027746

ER -