Trends in Sq related to secular movements of the magnetic equator and variations in the Earth?s magnetic field

BLAS F. DE HARO BARBAS; MARTA ZOSSI DE ARTIGAS; ANA G. ELIAS

Puntarenas

Congreso; IX COLAGE; 2011

ALAGE (Asociación LatinoAmericana de Geofísica Espacial)

The solar quiet geomagnetic field variation, Sq, is mainly caused by the ionospheric current systems which flow in the E-region driven by electric fields generated by the atmospheric dynamo. The main variables in Sq are the ionospheric conductivities, the dynamo electric field, the solar diurnal tide and the E-region electron concentration.The Earth?s magnetic field, B, generated in the Earth?s core, presents long term variations in the field?s strength and orientation, and since the ionospheric conductivity depends on B, some effect should be expected in Sq. Sq variation of the horizontal intensity, H, of magnetic observatories at low latitudes are analyzed, so the secular movement of the magnetic equator is also included in the present analysis. The expected Sq trends in terms the secular variations of B and of the magnetic equator location are assessed and compared to the experimental ones.