Trends in the equatorial F2 region due to secular variations in the Earth?s magnetic field

ANA G. ELIAS; MARTA ZOSSI DE ARTIGAS; ALBERTO J. FOPPIANO; RODRIGO ABARCA DEL RIO

Boulder, Colorado

Workshop; 6th Workshop on Long-Term Changes and Trends in the Atmosphere; 2010

IAGA - ICMA - CAWSES, National Center for Atmospheric Research (NCAR)

Dynamics play a fundmental role in the equatorial ionosphere. In particular, during daytime in the equatorial F2 region, the eastward electric field (E) combined with the Earth?s magnetic field (B) drives a vertical plasma fountain at the magnetic equator creating the Equatorial Ionization Anomaly (EIA) characterized by an electron density trough at the magnetic dip equator with crests at 15º to 20° to the north and south. The EIA characteristics should vary then with the secular changes of B and of the dip equator geographic latitude. Considering the long-term variation in B and the dip equator movement since 1956, the trends induced in foF2 and hmF2 at latitudes around the trough and crests of the EIA, are analyzed together with the expected changes in the EIA pattern.