Modeling the response of the F2 ionospheric layer to changes in the geomagnetic dipole tilt angle using SUPIM

JONAS R. SOUZA; BRUNO S. ZOSSI; ANA G. ELIAS; BLAS F. DE HARO BARBAS

Hefei

Workshop; 10th Workshop on Long-Term Changes and Trends in the Atmosphere; 2018

University of Science and Technology of China

The F2 critical frequency foF2 and the peak electron density height hmF2 depend to some degree on the declination, D, and inclination, I, of the local Earth?s magnetic field. At present this field can be approximated by a magnetic dipole that accounts for ~80% of its value, with a tilt relative to the Earth?s rotation axis of ~11°. However, the geomagnetic field varies greatly in geological timescales in magnitude and in orientation, with the most drastic change being a polarity reversal that takes place on average every ~200 000 years. In the present work we analyze how changes in the dipole tilt angle from 10° to 60° affect foF2 and hmF2 using the Sheffield University Plasmasphere-Ionosphere Model (SUPIM) which is a first-principles model of the Earth´s ionosphere and plasmasphere that solves the coupled time-dependent equations of continuity, momentum, and energy balance along closed magnetic field lines. Changes in D and I, that result in our case from changes in the dipole tilt, directly affect foF2 and hmF2 through changes in the field lines along which ionization is transported up or down, according to local time, by electric fields and neutral winds.