E region electric fields at the dip equator and anomalous conductivity effects

Made available in DSpace on 2019-09-12T16:53:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2013Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Instituto Nacional de Pesquisas Espaciais (INPE)Zonal and vertical electric fields were estimated at E region heights in the Brazilian sector. Zonal electric fields are obtained from the vertical electric fields based on their relation through the Hall-to-Pedersen ionospheric conductivities ratio. The technique for obtaining the vertical electric field is based on its proportionality to the Doppler velocities of type 2 irregularities as detected by coherent radars. The 50 MHz backscatter coherent (RESCO) radar was used to estimate the Doppler velocities of the type 2 irregularities embedded in the equatorial electrojet. A magnetic field-line integrated conductivity model was developed to provide the conductivities. It considers a multi-species ionosphere and a multi-species neutral atmosphere, and uses the IRI 2007, the MISTS 2000 and the IGRF 10 models as input parameters for ionosphere, neutral atmosphere and Earth's magnetic field, respectively. The ion-neutral collision frequencies of all the species are combined through the momentum transfer collision frequency equation, and different percentages of electron-neutral collisions were artificially included for studying the implication of such increase in the zonal electric field, which resulted ranging from 0.13 to 0.49 mV/m between the 8 and 18 h (LT), under quiet magnetic conditions. (C) 2012 COSPAR. Published by Elsevier Ltd. All rights reserved.[Denardini, C. M.; Sobral, J. H. A.; Bageston, J. V.; Guizelli, L. M.; Resende, L. C. A.; Moro, J.] Natl Inst Space Res, Aeron Div, Sao Jose Dos Campos, SP, Brazil[Aveiro, H. C.] Cornell Univ, Ithaca, NY USA[Guizelli, L. M.] Universidade de Taubaté (Unitau), Dept Elect Eng