| Full text | |
| Author(s): |
Nogueira, Paulo A. B.
[1]
;
Abdu, Mangalathayil A.
[2]
;
Souza, Jonas R.
[2]
;
Denardini, Clezio M.
[2, 3]
;
Barbosa Neto, Paulo F.
[2, 3]
;
Serra de Souza da Costa, Joao P.
[1]
;
Silva, Ana P. M.
[1]
Total Authors: 7
|
| Affiliation: | [1] Fed Inst Educ Sci & Technol Sao Paulo, Sao Paulo - Brazil
[2] Inst Nacl Pesquisas Espaciais, Div Aeron, BR-12227010 Sao Jose Dos Campos, SP - Brazil
[3] Inst Nacl Pesquisas Espaciais, Embrace Space Weather Program, BR-12227010 Sao Jose Dos Campos, SP - Brazil
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | Annales Geophysicae; v. 36, n. 1, p. 139-147, JAN 25 2018. |
| Web of Science Citations: | 2 |
| Abstract | |
Ionosphere (equatorial ionosphere)We have analyzed low-latitude ionospheric current responses to two intense (X-class) solar flares that occurred on 13 May 2013 and 11 March 2015. Sudden intensifications, in response to solar flare radiation impulses, in the S-q and equatorial electrojet (EEJ) currents, as detected by magnetometers over equatorial and low-latitude sites in South America, are studied. In particular we show for the first time that a 5 to 8 min time delay is present in the peak effect in the EEJ, with respect that of S-q current outside the magnetic equator, in response to the flare radiation enhancement. The S-q current intensification peaks close to the flare X-ray peak, while the EEJ peak occurs 5 to 8 min later. We have used the Sheffield University Plasmasphere-Ionosphere Model at National Institute for Space Research (SUPIM-INPE) to simulate the E-region conductivity enhancement as caused by the flare enhanced solar extreme ultraviolet (EUV) and soft X-rays flux. We propose that the flare-induced enhancement in neutral wind occurring with a time delay (with respect to the flare radiation) could be responsible for a delayed zonal electric field disturbance driving the EEJ, in which the Cowling conductivity offers enhanced sensitivity to the driving zonal electric field. (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 |