Ionospheric electron and ion temperatures anomalies due to the phenomena 
occurring below and above it as measured by SROSS-C2 satellite 

D. K. SHARMA 
Department of Applied Sciences & Humanities, 
Manav Rachna College of Engineering, Faridabad 121001, India 
 
 
ABSTRACT 
 
It has been suggested that the phenomena occurring below the ionosphere such as 
thunderstorms, lightning/ sprites, volcanic eruptions and earthquake and above 
the phenomena like: corona mass ejection, solar flares and extra terrestrial 
events may produce F2 layer signatures. In the present paper we have tried to 
summarize the effect of some phenomena occurring below the ionosphere like 
thunderstorms, lightning/ sprites and seismic activity and the phenomena such as 
solar flares which occur above the ionosphere, on the ionospheric electron and 
ion temperatures. The paper also discusses possibilities.       
The ionospheric electron and ion temperatures were measured by the RPA payload 
aboard the Indian SROSS-C2 satellite. The normal day’s ion and electron 
temperatures have been compared to the temperatures recorded during the 
disturbed day. The satellite data were analyzed to corresponding disturbance 
period in such away that the other possible effects are eliminated.  The data 
are used from the period 1995-1998 in the altitude range 430-630 km over the 
Indian region. The data of thunderstorms activity have been obtained from IMD, 
Pune and details of seismic events during this period down loaded from the USGS 
website and existing literature.  The data of solar flares have obtained from 
NGDC, Boulder, Colorado, USA. It has been found that there is a consistent 
enhancement of ionospheric electron and ion temperatures recorded during active 
thunderstorms period. This enhancement was for the average electron temperature 
ranging from 1.2 to 1.7 times compare to the average normal day’s temperature. 
However, for ion temperature this enhancement was from 1.1 to 1.5 times. During 
the earthquake events this enhancement was for electron temperature ranging from 
1.2 to 1.5 times and was for ion temperature from 1.1 to 1.3 times over the normal 
day’s average temperatures. Similar enhancements of the ionospheric electron and ion 
temperatures have been recorded during the solar flares. This enhancement for 
the average electron temperature varies from 1.3 to 1.9 times to the normal 
day’s average temperature. However, for ion temperature it ranging from 1.2 to 
1.4 times to the normal days average temperature has been observed. No measurable 
enhancement in electron and ion temperatures has been found during the night hours. 
 
 
Key words: Ionospheric temperatures; F2 region; thunderstorms; seismic activity; 
solar flares.