Solar flux effects on the equatorial evening vertical drift and meridional winds over Brazil: A comparison between observational data and the IRI model and the HWM representations

Autor(es)

Abdu, M. A. ^[1] ; Batista, I. S. ^[1] ; Brum, C. G. M. ^[2] ; MacDougall, J. W. ^[3] ; Santos, A. M. ^[1] ; de Souza, J. R. ^[1] ; Sobral, J. H. A. ^[1]

Afiliação do(s) autor(es)

^[1] INPE, BR-12201970 Sao Paulo - Brazil

^[2] Natl Astron & Ionosphere Ctr, Space & Atmospher Sci Dept, Arecibo Observ Atmospher Sci, Arecibo, PR 00612 - USA

^[3] Univ Western Ontario, Dept Elect Engn, London, ON N6A 5B9 - Canada

• Tipo de documento: Artigo Científico
• Fonte: Advances in Space Research; v. 46, n. 8, p. 1078-1085, OCT 15 2010.
• Citações Web of Science: 13

Resumo

We present the results of a study of the equatorial evening F region prereversal vertical drift enhancement over Brazil as a function of solar flux (F10.7). The vertical drift is measured from true heights obtained from digisondes operated at an equatorial site, Sao Luis, and at an off equatorial site, Fortaleza. The different magnetic inclinations of the two sites cause different degree of dependence of the vertical drift on magnetic meridional winds permitting an evaluation of the solar flux control on both the evening vertical drift (zonal electric field) and meridional winds. The analysis period covers the year 2001 and 2004 during which the monthly mean F10.7 varied from 245 to 80. The solar flux dependence of the vertical drift of the evening F layer as obtained from the data are compared with the representation of such dependence in the IRI model. While the IRI description of such dependence appears comparable to that is determined from observational data there is significant difference between the drift values in the two cases, the IRI representation being an underestimation of the observed drift for all flux values. The results are discussed from the perspective of validating the IRI model representations of the vertical drift. The results of the study also shows that the HWM description of the evening thermospheric meridional wind in the Brazilian sector, shows agreement with observation for lower F10.7 values, while it significantly deviates from the observed/calculated meridional wind for higher solar flux values. (C) 2010 Published by Elsevier Ltd. on behalf of COSPAR. (AU)

• Processo FAPESP: 99/00437-0 - Estudos dos processos interativos do sistema ionosfera-termosfera equatorial
• Beneficiário: Mangalathayil Ali Abdu
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 04/07695-5 - Estudo da baixa ionosfera do setor sul americano via riometro e mudancas globais associadas.
• Beneficiário: Christiano Garnett Marques Brum
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 05/52654-8 - Estudo da baixa ionosfera do setor sul americano via riometro e mudancas globais associadas.
• Beneficiário: Christiano Garnett Marques Brum
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 05/59433-7 - Estudo da baixa ionosfera do setor sul americano e mudanças globais associadas - estágio no exterior
• Beneficiário: Christiano Garnett Marques Brum
• Modalidade de apoio: Bolsas no Exterior - Pesquisa