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IJRSP Vol.41 [2012] >
IJRSP Vol.41(3) [June 2012] >
| Title: | foF2 variations during geomagnetic disturbances at the rise of solar cycle 23 |
| Authors: | Adebesin, B Olufemi |
| Keywords: | F2 layer critical frequency
Geomagnetic disturbances
Solar radiance
Solar cycle 23
Electron density |
| Issue Date: | Jun-2012 |
| Publisher: | NISCAIR-CSIR, India |
| PACS No.: | 91.25.Rt; 94.20.dj; 94.20.Vv |
| Abstract: | The
present work emphasizes on foF2, the critical frequency of the F2 layer,
variations during peak geomagnetic disturbances (Dst ≤ -100 nT) at the rise of
solar cycle 23. Geomagnetic, interplanetary and solar wind parameters have been
studied as well as foF2 data from five ionosonde stations in the Asian sector.
The study shows that: (i) the observed enhancement immediately after sunset at
Petropavlovsk compared with foF2 upwelling after sunrise at Magadan after the
storm on 12 February 2000 revealed that there is no simultaneity in foF2 during
the activity, (ii) the variation of foF2 along a line of fixed latitude, as it
occurs at four stations during the 12 August 2000 storm, shows the diurnal
anomaly, which depends on the season and epoch of the solar cycle, reaching
maximum before sunrise, and (iii) at any latitude, factors other than solar
radiance play an important role in determining the foF2 variations. The results
seem to agree with earlier works. The morphology of both positive and negative
phase storms is also discussed. |
| Page(s): | 323-331 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-105X (Online); 0367-8393 (Print) |
| Source: | IJRSP Vol.41(3) [June 2012]
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