EARTHQUAKE TIME LOW LATITUDE TEC AND MODEL ESTIMATED VALUES: IDENTIFICATION ON EARTHQUAKE INDUCED ATMOSPHERIC DYNAMICS

The paper aims at understanding atmospheric system during earthquake preparatory processes through features of Total Electron Content (TEC) taken by GPS at Guwahati (26° 10′ N, 91° 45′ E), an anomaly crest station. It is noted that earthquakes occurring at equator (within same longitude zone of Guwahati) have little impact on pre-earthquake TEC variations over Guwahati, but the low-latitude ones show their imprints on TEC even when their epicenters lie at 500–600 km longitudinal separation. This paper discusses how electric field generated in the earthquake preparatory processes works in a complex manner at the equatorial anomaly zone in a way similar to electro jet current system, leading to changes in ionospheric parameters. Finally attempts are made to understand the situation prior to and during a seismic event by assigning parameters with special reference to IRI model, for obtaining the observed results.