AN ANALYSIS OF THE TOTAL ELECTRON CONTENT AT THREE LOW LATITUDE STATIONS IN THE SOUTH AMERICAN REGION

M. MOSERT, R. EZQUER, C.BRUNINI, M. GENDE, E. GULARTE

San Miguel de Tucumán

Otro; XXVI Reunión Científica de la Asociación Argentina de Geofísicos y Geodesias; 2012

Universidad Nacional de Tucumán, Universidad Nacional de Cuyo

The objective of this paper is to analyze the variations of the total electron content (TEC) using data observed during different seasonal and solar activity conditions at three low-latitude stations: Jicamarca (-12.0°S; 283°E); Tucumán (-26.9°S; 294.6°E) and San Juan (-31.5°S; 290.4°E). The TEC measurements have been derived from GPS satellite signals and from ground-based ionosonde data. Comparisons between TEC observations and the IRI-2007 predictions and an analysis of the day to day variability of TEC are also done. In general, the shape of the diurnal and seasonal variations of TEC observations is similar to those predicted by IRI. The IRI predictions generally overestimate the total electron content during nighttime and underestimate during daytime. Taking into account that the most contribution of TEC comes from the topside electron density profile, topside scatter radar profiles obtained in Jicamarca have been compared with the model predictions, in order to confirm if the discrepancies between observations and predictions are due to the shape of the topside electron density profile proposed by IRI. The study also shows that the day to day variability of TEC is greater during nighttime that during daytime