Equatorial 150 km echoes and daytime F region vertical plasma drifts in the Brazilian longitude sector

Autor(es)

Rodrigues, F. S. ^[1] ; Shume, E. B. ^[2] ; de Paula, E. R. ^[3] ; Milla, M. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Texas Dallas, William B Hanson Ctr Space Sci, Richardson, TX 75083 - USA

^[2] CALTECH, Jet Prop Lab, Pasadena, CA - USA

^[3] Inst Nacl Pesquisas Espaciais, BR-12201 Sao Jose Dos Campos - Brazil

^[4] Jicamarca Radio Observ, Lima - Peru

• Tipo de documento: Artigo Científico
• Fonte: Annales Geophysicae; v. 31, n. 10, p. 1867-1876, 2013.
• Citações Web of Science: 7

Resumo

Previous studies showed that conventional coherent backscatter radar measurements of the Doppler velocity of the so-called 150 km echoes can provide an alternative way of estimating ionospheric vertical plasma drifts during daytime hours (Kudeki and Fawcett, 1993; Chau and Woodman, 2004). Using observations made by a small, low-power 30MHz coherent backscatter radar located in the equatorial site of Sao Luis (2.59 degrees S, 44.21 degrees W; -2.35 degrees dip lat), we were able to detect and monitor the occurrence of 150 km echoes in the Brazilian sector. Using these measurements we estimated the local time variation of daytime vertical ionospheric drifts in the eastern American sector. Here, we present a few interesting cases of 150 km-echoes observations made by the Sao Luis radar and estimates of the diurnal variation of vertical drifts. These cases exemplify the variability of the vertical drifts in the Brazilian sector. Using same-day 150 km-echoes measurements made at the Jicamarca Radio Observatory in Peru, we also demonstrate the variability of the equatorial vertical drifts across the American sector. In addition to first estimates of the absolute vertical plasma drifts in the eastern American (Brazilian) sector, we also present observations of abnormal drifts detected by the Sao Luis radar associated with the 2009 major sudden stratospheric warming event. (AU)

• Processo FAPESP: 04/01065-0 - Imageamento das irregularidades ionosféricas por radar VHF
• Beneficiário: Eurico Rodrigues de Paula
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 99/00026-0 - Estudos das irregularidades ionosféricas utilizando radar HF/VHF/ de espalhamento coerente
• Beneficiário: Eurico Rodrigues de Paula
• Modalidade de apoio: Auxílio à Pesquisa - Regular