| Full text | |
| Author(s): |
Venkatesh, K.
;
Ram, S. Tulasi
;
Fagundes, P. R.
;
Seemala, Gopi K.
;
Batista, I. S.
Total Authors: 5
|
| Document type: | Journal article |
| Source: | JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS; v. 122, n. 4, p. 4553-4570, APR 2017. |
| Web of Science Citations: | 13 |
| Abstract | |
The St. Patrick's Day storm of 17 March 2015 has a long-lasting main phase with the Dst reaching a minimum of -223nT. During the main phase, two strong prompt penetration electric field (PPEF) phases took place; first with the southward turning of IMF Bz around similar to 1200UT and the second with the onset of a substorm around similar to 1725UT leading to strong equatorial zonal electric field enhancements. The consequent spatiotemporal disturbances in the ionospheric total electron content and the resultant modifications in the equatorial ionization anomaly (EIA) over the Brazilian longitudinal sector are investigated in detail. The simultaneous measurements from a large network of GPS receivers, ionosonde, and magnetometers over the Brazilian longitudinal sector are used for this study. In the presence of enhanced zonal electric field, the equatorial F-2 layer peak (h(m)F(2)) experienced a rapid uplift without any significant change in the base height (h'F); while the F-2 layer is redistributed into F-2 and F-3 layers. The enhanced zonal electric filed due to PPEF led to the strong super fountain effect under which the anomaly crest departed poleward to similar to 40 degrees S latitude. In the presence of westward and equatorward wind surge over Brazil with the coexisting disturbance dynamo fields, strong hemispheric asymmetry is seen in the storm time response of EIA during both the PPEF phases. (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 |