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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.)

Longitudinal variation in Global Navigation Satellite Systems TEC and topside ion density over South American sector associated with the four-peaked wave structures

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Author(s):
Nogueira, P. A. B. [1] ; Abdu, M. A. [1] ; Souza, J. R. [1] ; Bailey, G. J. [2] ; Batista, I. S. [1] ; Shume, E. B. [3] ; Denardini, C. M. [1]
Total Authors: 7
Affiliation:
[1] Inst Nacl Pesquisas Espaciais, Div Aeron, Sao Jose Dos Campos - Brazil
[2] Univ Sheffield, Dept Appl Math, Sheffield, S Yorkshire - England
[3] CALTECH, Jet Prop Lab, Pasadena, CA - USA
Total Affiliations: 3
Document type: Journal article
Source: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS; v. 118, n. 12, p. 7940-7953, DEC 2013.
Web of Science Citations: 8
Abstract

Recent observations of the low-latitude ionospheric electron density revealed a four-peaked longitudinal structure in the equatorial ionization anomaly when plotted at a constant-local-time frame. It was proposed that neutral wind-driven E region dynamo electric fields due to nonmigrating tidal modes are responsible for this pattern. We examine the four-peaked structure in the observed topside ion density and its manifestation as longitudinal structures in total electron content (TEC) over South America. The strong longitudinal variation in TEC characterized by larger value over Brazilian eastern longitude sector as compared to that over the Peruvian western longitude is modeled using the Sheffield University plasmasphere-ionosphere model (SUPIM) aiming to identify the control factors responsible for the longitude variation. We found that the SUPIM runs using as input the existing standard models of vertical drift, and thermospheric winds do not explain the TEC longitudinal structure. Realistic values of these control parameters were generated based on the strong vertical drift longitudinal variation as determined from magnetometer and Digisonde data and appropriately adjusted winds (horizontal wind model). These realistic vertical drifts together with the modified thermospheric wind, when used as input to the SUPIM, are found to satisfactorily explain the longitudinal differences in the TEC and topside ion density (Ni) over South America. The study shows that the TEC in the whole latitude distribution is larger over the east coast than over the west coast of South America and that the vertical drift and thermospheirc winds control the longitudinal four wave structure in the TEC and Ni. (AU)

FAPESP's process: 12/08445-9 - Study of day-to-day variability of the mesosphere, thermosphere and ionosphere at low latitude and equatorial region, during the solar cycle 24
Grantee:Paulo Roberto Fagundes
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 13/01924-1 - FORECAST MODEL OF TOTAL ELECTRON CONTENT OVER SOUTH AMERICA
Grantee:Paulo Alexandre Bronzato Nogueira
Support Opportunities: Scholarships in Brazil - Post-Doctoral