Storm time equatorial plasma bubble zonal drift reversal due to disturbance Hall electric field over the Brazilian region

Author(s)

Santos, A. M. ; Abdu, M. A. ; Souza, J. R. ; Sobral, J. H. A. ; Batista, I. S. ; Denardini, C. M.

• Document type: Journal article
• Source: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS; v. 121, n. 6, p. 5594-5612, JUN 2016.
• Web of Science Citations: 6

Abstract

The dynamics of equatorial ionospheric plasma bubbles over Brazilian sector during two magnetic storm events are investigated in this work. The observations were made at varying phases of magnetic disturbances when the bubble zonal drift velocity was found to reverse westward from its normally eastward velocity. Calculation of the zonal drift based on a realistic low-latitude ionosphere modeled by the Sheffield University Plasmasphere-Ionosphere Model showed on a quantitative basis a clear competition between vertical Hall electric field and disturbance zonal winds on the variations observed in the zonal velocity of the plasma bubble. The Hall electric field arising from enhanced ratio of field line-integrated conductivities, Sigma(H)/Sigma(P), is most often generated by an increase in the integrated Hall conductivity, arising from enhanced energetic particle precipitation in the South American Magnetic Anomaly region for which evidence is provided from observation of anomalous sporadic E layers over Cachoeira Paulista and Fortaleza. Such sporadic E layers are also by themselves evidence for the development of the Hall electric field that modifies the zonal drift. (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