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Indian Journal of Radio & Space Physics (IJRSP) >
IJRSP Vol.41 [2012] >
IJRSP Vol.41(2) [April 2012] >
| Title: | Behaviour of the low-latitude ionosphere-plasmasphere system at long deep solar minimum |
| Authors: | Balan, N
Chen, C Y
Liu, J Y
Bailey, G J |
| Keywords: | Electron temperature, Equatorial ionization anomaly
Ionosphere-plasmasphere system, Ion temperature
Plasma flux, Vertical ion drift velocity
Wind velocity |
| Issue Date: | Apr-2012 |
| Publisher: | NISCAIR-CSIR, India |
| PACS No.: | 94.20.dt; 94.20.Vv |
| Abstract: | The behaviour of the low-latitude ionosphere-plasmasphere system during the
long deep solar minimum between solar cycles 23 and 24 is presented using the
physics based model SUPIM and FORMOSAT-3/COSMIC satellite data. Using the
vertical ion drift velocity measured by C/NOFS satellite, and neutral densities
and wind velocities obtained from MSIS and HWM, SUPIM calculates the electron
and ion (O+, H+, He+, N2+,
O2+, and NO+) densities and temperatures and
plasma fluxes within ±40o magnetic latitudes and 150-2000 km heights
for Indian longitudes at equinox (F10.7 = 68, Ap = 4). FORMOSAT-3 measures the
corresponding electron density up to 600 km height. The data and model show the
ionosphere contracting to a thin layer during the long deep solar minimum.
During daytime, the ionosphere has a half-width of only about 250 km over the
equator and 150 km at EIA crests with a peak density of about 106 cm-3
and O+/H+ transition height at around 750 km. At night,
the ionosphere reduces to a cold thin layer of half-width less than about 150
km at the crests with a peak density of about 105 cm-3,
and transition height about 500 km where the ion densities reduce to about 104
cm-3. Plasma density in the plasmasphere (above transition height)
remains nearly constant at about 104 cm-3 during both day
and night, and decreases only very slowly with height. However, the
temperatures increase rapidly at sunrise at all heights to reach about 2500 K
(electron) and 2250 K (ion) at 0800 hrs LT at 2000 km height (at EIA crests),
which decrease by a maximum of only 250 K until sunset. After sunset, both
electrons and ions cool rapidly until about midnight and then decrease slowly
to nearly constant temperatures at all heights to about 650 K prior to sunrise.
SUPIM predictions and FORMOSAT-3 data agree also with C/NOFS and CHAMP
satellite observations. |
| Page(s): | 89-97 |
| 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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