AN ANALYISIS OF IONOSPHERIC PARAMETERS OVER THE ANTARCTIC SECTOR USING DIFFERENT TECHNIQUES.

MOSERT, M. 1, MCKINNELL L.A 2,3, EZQUER R.G.4,5 , BRUNINI, C.6 , GENDE, M 6., ARAUJO,J.7

Mendoza, Argentina

Otro; XXIV Reunión Cintífica de la AAGG; 2009

Universidad Nacional de Cuyo

The objective of this paper is to analyze the behaviour of the ionosphere over the Antarctic region using ionosonde data and GPS measurements. The data base includes hourly monthly median values of the critical frequency of the F2 region observed (foF2) at San Martín (68.1°S; 293.0°E geographic; 53° S magnetic) and  Belgrano (77.9°S; 321.4°E geographic, 67.5° magnetic).The vertical GPS total electron content values (GPS TEC) have been derived from observations at O´Higgins (63.3°S, 302.5°E; magnetic 48.6°S). Data from different hours, seasons and solar activity periods are considered.  The results show that the foF2 daily peak in the Antarctic stations occurs around the local noon in winter and fall. In summer a maximum diurnal value of foF2 is observed during night time and a minimum diurnal value of foF2 is found around noon, exhibiting an anomalous diurnal variation of foF2.This behaviour is observed at low solar activity and high solar activity. The winter anomaly is not observed in foF2 but the semi annual one is present around noon or post noon hours. The solar activity effect on foF2 is observed: the values are higher during high solar activity than during low solar activity. Related to the total electron content derived from GPS observations, similar variations have been observed. The observational database in the Antarctic Sector can help to describe better the morphology and modelling of the high latitude ionosphere particularly in the Southern hemisphere. Keywords: Ionosphere; High latitude; Critical frequency; GPS total electron content