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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Ionospheric zonal velocities at conjugate points over Brazil during the COPEX campaign: Experimental observations and theoretical validations

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Sobral, J. H. A. [1] ; Abdu, M. A. [1] ; Pedersen, T. R. [2] ; Castilho, Vivian M. [1] ; Arruda, Daniela C. S. [1] ; Muella, M. T. A. H. [1] ; Batista, I. S. [1] ; Mascarenhas, M. [1] ; de Paula, E. R. [1] ; Kintner, P. M. [3] ; Kherani, E. A. [1] ; Medeiros, A. F. [4] ; Buriti, R. A. [4] ; Takahashi, H. [1] ; Schuch, N. J. [1] ; Denardini, C. M. [1] ; Zamlutti, C. J. [1] ; Pimenta, A. A. [1] ; de Souza, J. R. [1] ; Bertoni, F. C. P. [5]
Total Authors: 20
[1] Inst Nacl Pesquisas Espaciais, BR-12201970 Sao Jose Dos Campos - Brazil
[2] AFRL RVBXI, AF Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 - USA
[3] Cornell Univ, Dept Elect Engn, Ithaca, NY 14853 - USA
[4] Univ Fed Campinas Grande, Dept Fis, BR-58109970 Campina Grande, Paraiba - Brazil
[5] Univ Luterano Brasil Palmas, Ctr Univ Luterano Palmas, Tocantins - Brazil
Total Affiliations: 5
Document type: Journal article
Web of Science Citations: 38

We analyze in detail the zonal velocities of large-scale ionospheric plasma depletions over two conjugate stations inferred from OI 630 nm airglow all-sky images obtained during the Conjugate Point Equatorial Experiment (COPEX) campaign carried out in Brazil between October and November 2002. The conjugate stations were Boa Vista (BV) (geogr. 2.8N, 60.7W, dip angle 22.0 degrees N) and Campo Grande (CG) (geogr. 20.5S, 54.7W, dip angle 22.32 degrees S). Over Campo Grande, the zonal velocities were measured also by a system of spaced GPS scintillation receivers. The airglow zonal velocities at the conjugate sites were seen to agree very closely, except for a slightly increased velocity over CG which we attribute to the presence of the geomagnetic anomaly. The results show a high degree of alignment of the bubbles along the geomagnetic field lines during the bubble development phase and as the bubbles travel eastward, thereby suggesting that the neutral zonal wind effect in the zonal plasma motion is an integrated effect along the flux tube. The zonal velocities obtained from the GPS technique were always larger than those calculated by the airglow technique, which permitted observation of zonal plasma velocity shear between the altitudes of the airglow emitting layer and of the GPS scintillation. Theoretical ambient plasma zonal velocities calculated using the formulations by Haerendel et al. (1992) and Eccles (1998) are compared with the experimental results. Our results also reveal some degree of dependence of the zonal velocities on the solar flux (F10.7) and magnetic (Kp) indices during the COPEX period. (AU)

FAPESP's process: 99/00437-0 - Studies of the interactive processes of the equatorial ionosphere-thermosphere system
Grantee:Mangalathayil Ali Abdu
Support Opportunities: Research Projects - Thematic Grants