Equatorial ionosphere responses to two magnetic storms of moderate intensity from conjugate point observations in Brazil

被引：34

作者：

Abdu, M. A. ^{[1
]}

Batista, I. S. ^{[1
]}

Bertoni, F. ^{[2
]}

Reinisch, B. W. ^{[3
,4
]}

Kherani, E. A. ^{[1
]}

Sobral, J. H. A. ^{[1
]}

机构：

[1] Inst Nacl Pesquisas Espaciais, BR-12201970 Sao Jose Dos Campos, SP, Brazil

[2] Univ Prebiteriana Mackenzie, CRAAM, Sao Paulo, Brazil

[3] Lowell Digisonde Int LLC, Lowell, MA USA

[4] Univ Massachusetts, Ctr Atmospher Res, Lowell, MA USA

来源：

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS | 2012年 / 117卷

关键词：

PREREVERSAL ELECTRIC-FIELD; LOW-LATITUDE IONOSPHERE; REGION PLASMA DRIFTS; SPREAD-F; DISTURBANCE DYNAMO; NONLINEAR EVOLUTION; WIND CONTROL; DIGISONDE; BUBBLE; MODEL;

D O I：

10.1029/2011JA017174

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Equatorial ionospheric responses during two magnetic storms of moderate intensity are investigated, for the first time, by conjugate point observations in Brazil. The study focuses on storm-induced changes in the evening prereversal vertical drift, thermospheric trans-equatorial winds, spread F/plasma bubble irregularity development, electron density/plasma frequency heights, the EIA strength, and zonal plasma drifts. It is based on data obtained from five Digisondes operated in Brazil, three of them being part of a conjugate point equatorial experiment (COPEX) involving a dip equatorial and two magnetic conjugate sites at +/- 12 degrees. The other two were operated at the equatorial ionization anomaly (EIA) trough and crest locations at nearby magnetic meridians. The results bring out, and clarify, many outstanding aspects of the strong influence of storm time electric fields on the equatorial ionosphere at different phases of the two long lasting storm sequences. During both storms prompt penetration electric fields dominated the ionospheric response features as compared to the disturbance wind dynamo effects that were not very conspicuous. An under-shielding (over-shielding) electric field occurring in the evening hours causes enhancement (suppression) of the prereversal vertical drift and post sunset spread F/plasma bubble generation. The same electric fields cause post sunset EIA enhancement and suppression, respectively. Post sunset (post midnight) spread F can develop from under-shielding (over-shielding) electric fields, while it can be disrupted by over-shielding (under-shielding) electric field. Trans-equatorial winds are found to be ineffective to stabilize the post sunset F region against the destabilizing effect of strong prereversal vertical drift. Storm time westward plasma drifts are found to be driven by prompt penetration eastward electric fields (through their effect of inducing vertical Hall electric fields), rather than by a disturbance westward thermospheric wind during these storms.

引用

页数：20

共 81 条

[1] Abnormal evening vertical plasma drift and effects on ESF and EIA over Brazil-South Atlantic sector during the 30 October 2003 superstorm [J].

Abdu, M. A. ;

de Paula, E. R. ;

Batista, I. S. ;

Reinisch, B. W. ;

Matsuoka, M. T. ;

Camargo, P. O. ;

Veliz, O. ;

Denardini, C. M. ;

Sobral, J. H. A. ;

Kherani, E. A. ;

de Siqueira, P. M. .

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2008, 113 (A7)

[2] Equatorial evening prereversal vertical drift and spread F suppression by disturbance penetration electric fields [J].

Abdu, M. A. ;

Kherani, E. A. ;

Batista, I. S. ;

Sobral, J. H. A. .

GEOPHYSICAL RESEARCH LETTERS, 2009, 36

[3] Gravity wave initiation of equatorial spread F/plasma bubble irregularities based on observational data from the SpreadFEx campaign [J].

Abdu, M. A. ;

Kherani, E. Alam ;

Batista, I. S. ;

de Paula, E. R. ;

Fritts, D. C. ;

Sobral, J. H. A. .

ANNALES GEOPHYSICAE, 2009, 27 (07) :2607-2622

[4] Conjugate Point Equatorial Experiment (COPEX) campaign in Brazil: Electrodynamics highlights on spread F development conditions and day-to-day variability [J].

Abdu, M. A. ;

Batista, I. S. ;

Reinisch, B. W. ;

de Souza, J. R. ;

Sobral, J. H. A. ;

Pedersen, T. R. ;

Medeiros, A. F. ;

Schuch, N. J. ;

de Paula, E. R. ;

Groves, K. M. .

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2009, 114

[5] Planetary wave oscillations in mesospheric winds, equatorial evening prereversal electric field and spread F [J].

Abdu, MA ;

Batista, PP ;

Batista, IS ;

Brum, CGM ;

Carrasco, AJ ;

Reinisch, BW .

GEOPHYSICAL RESEARCH LETTERS, 2006, 33 (07)

[6] Thermospheric meridional wind control of equatorial spread F and evening prereversal electric field [J].

Abdu, MA ;

Iyer, KN ;

de Medeiros, RT ;

Batista, IS ;

Sobral, JHA .

GEOPHYSICAL RESEARCH LETTERS, 2006, 33 (07)

[7] South Atlantic magnetic anomaly ionization: A review and a new focus on electrodynamic effects in the equatorial ionosphere [J].

Abdu, MA ;

Batista, IS ;

Carrasco, AJ ;

Brum, CGM .

JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, 2005, 67 (17-18) :1643-1657

[8] Magnetospheric disturbance induced equatorial plasma bubble development and dynamics: A case study in Brazilian sector [J].

Abdu, MA ;

Batista, IS ;

Takahashi, H ;

MacDougall, J ;

Sobral, JH ;

Medeiros, AF ;

Trivedi, NB .

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2003, 108 (A12)

[9]

ABDU MA, 1990, ANN GEOPHYS, V8, P419

[10] Equatorial F region zonal plasma irregularity drifts under magnetospheric disturbances [J].

Abdu, MA ;

Jayachandran, PT ;

MacDougall, J ;

Cecile, JF ;

Sobral, JHA .

GEOPHYSICAL RESEARCH LETTERS, 1998, 25 (22) :4137-4140

← 1 2 3 4 5 6 7 8 9 →