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Indian Journal of Radio & Space Physics (IJRSP) >
IJRSP Vol.41 [2012] >
IJRSP Vol.41(2) [April 2012] >
| Title: | Equinoctial and June solstitial F-region irregularities over Sanya |
| Authors: | Guozhu, Li
Ning, Baiqi
Liu, Libo
Wan, Weixing
Hu, Lianhuan
Zhao, Biqiang
Patra, A K |
| Keywords: | Field aligned irregularity (FAI)
Equatorial plasma bubble
GPS scintillation
Equatorial F-region irregularities
Total electron content (TEC) fluctuations |
| Issue Date: | Apr-2012 |
| Publisher: | NISCAIR-CSIR, India |
| PACS No.: | 94.20.dj; 94.20.Vv |
| Abstract: | A 47.5 MHz VHF radar with a peak power of 24
kW has been operated at Sanya (18°N, 109°E, dip 13ºN) in Hainan Island, China
since February 2009. Data from the continuous observations of F-region
irregularities by the VHF radar, an ionosonde and a GPS scintillation/TEC
receiver during the equinoctial and June solstitial months of 2009-2010 have
been analyzed. It is found that the F-region 3-m scale field aligned
irregularities (FAIs) appeared frequently at post-sunset hours during equinox
but initiated mostly at midnight/post-midnight in June solstice. Comparison of
FAIs with GPS scintillations, TEC fluctuations and spread-F shows that the
equinoctial FAIs coincided well with GPS scintillations and TEC fast
depletions, which are associated with the development of equatorial plasma
bubbles (EPBs). However, for the June solstitial FAIs, the simultaneous
Communication/Navigation Outage Forecasting System (C/NOFS) satellite in situ density measurements show that
some post-midnight FAI structures over Sanya may originate from equatorial
F-region and then extend to Sanya latitude along magnetic field lines, but the
others could resemble the irregularities of localized origin, not associated
with the equatorial process. Both types of post-midnight FAIs during June
solstice are not accompanied by GPS scintillations and TEC depletions, but are
associated with the occurrence of spread-F. Possible mechanisms responsible for
the occurrence of post-midnight FAIs without GPS scintillations over Sanya have
been discussed. |
| Page(s): | 184-198 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-105X (Online); 0367-8393 (Print) |
| Source: | IJRSP Vol.41(2) [April 2012]
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