Print version ISSN 0187-6236
Some of well known F2 layer anomalies might have their origin in lower atmosphere and some have extra terrestrial sources. It has been suggested that the phenomena occurring below the ionosphere such as thunderstorms, lightning/sprites, volcanic eruptions and earthquakes 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 corresponding to the disturbance period were analyzed in such way that the other possible effects were eliminated. The data used are 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 downloaded from the USGS website and existing literature. The data of solar flares have been obtained from NGDC, Boulder, Colorado, USA.
Keywords : Ionospheric temperatures; F2 region; thunderstorms; seismic activity; solar flares.