Počet záznamů: 1
On the origin of lower- and upper-frequency cutoffs on wedge-like spectrograms observed by DEMETER in the midlatitude ionosphere
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SYSNO ASEP 0343319 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název On the origin of lower- and upper-frequency cutoffs on wedge-like spectrograms observed by DEMETER in the midlatitude ionosphere Tvůrce(i) Shklyar, D. R. (RU)
Parrot, M. (FR)
Chum, Jaroslav (UFA-U) RID, ORCID
Santolík, Ondřej (UFA-U) RID, ORCID
Titova, E. E. (RU)Zdroj.dok. Journal of Geophysical Research - ISSN 0148-0227
Roč. 115, - (2010), A05203/1-A05203/12Poč.str. 12 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova DEMETER ; midlatitude ionosphere ; spectrograms Vědní obor RIV BL - Fyzika plazmatu a výboje v plynech CEP ME09107 GA MŠMT - Ministerstvo školství, mládeže a tělovýchovy GA205/09/1253 GA ČR - Grantová agentura ČR CEZ AV0Z30420517 - UFA-U, BC-A (2005-2011) UT WOS 000277480900002 DOI 10.1029/2009JA014672 Anotace We report observations of unusual lower and upper cutoff frequencies on VLF spectrograms recorded by the DEMETER satellite orbiting at 700 km. The upper cutoff frequencies vary approximately in proportion to L-3. The lower cutoff frequencies in the spectrograms are almost constant. Between these cutoffs, which form a wedge, intense whistlers are observed, whereas only 0+ whistlers, and probably, ducted whistlers are present outside the cutoffs. We explain the observed spectrograms on the basis of the features of whistler-mode wave propagation in the inner magnetosphere. The upper cutoff frequency is determined by the limiting trajectories that confine the waves of a given frequency propagating obliquely from a source located in the opposite hemisphere. The lower frequency cutoff is determined by the LHR maximum, since quasiresonant waves with lower frequencies originating in the opposite hemisphere do not reach the satellite due to the LHR reflection above it. Pracoviště Ústav fyziky atmosféry Kontakt Kateřina Adamovičová, adamovicova@ufa.cas.cz, Tel.: 272 016 012 ; Kateřina Potužníková, kaca@ufa.cas.cz, Tel.: 272 016 019 Rok sběru 2011
Počet záznamů: 1