TY - JOUR

T1 - Modeling of the global distribution of ionospheric electric fields based on realistic maps of field-aligned currents

AU - Lukianova, Renata

AU - Christiansen, Freddy

PY - 2006/3/1

Y1 - 2006/3/1

N2 - A new approach for modeling the global distribution of ionospheric electric potentials utilizing high-precision maps of FACs derived from measurements by the Ørsted and Champ satellites as input to a comprehensive numerical scheme is presented. The boundary conditions provide a correct treatment of the asymmetry of conductivity and sources of electric potential between the northern and southern hemispheres. On the basis of numerical simulation the basic convection patterns developed simultaneously in both hemispheres for equinox and summer/winter solstices are obtained. A rather complicated dependence of the convection patterns on season linked with the sign of IMF BY is found. In particular, the combinations of BY > 0/summer and B Y < 0/winter produce the highest circular flow around the pole in comparison with the combinations of BY < 0/summer and B Y > 0/winter. The model predicts that the summer cross-polar potentials are smaller than the winter potentials. The value of the ratio depends on the combination of season/IMF BY sign. The ratio is found to be greater for the combination of BY > 0/southern summer and BY < 0/northern summer. The smallest value is obtained for the combination of BY < 0/southern summer and BY > 0/northern summer under northward IMF conditions. At middle latitudes the main features of the MLT-profile of the westward and equatorward electric field components are reproduced. The model predicts that during solstice the equatorward component of the midlatitude electric field is negative at all local times for BY < 0 and positive for BY > 0.

AB - A new approach for modeling the global distribution of ionospheric electric potentials utilizing high-precision maps of FACs derived from measurements by the Ørsted and Champ satellites as input to a comprehensive numerical scheme is presented. The boundary conditions provide a correct treatment of the asymmetry of conductivity and sources of electric potential between the northern and southern hemispheres. On the basis of numerical simulation the basic convection patterns developed simultaneously in both hemispheres for equinox and summer/winter solstices are obtained. A rather complicated dependence of the convection patterns on season linked with the sign of IMF BY is found. In particular, the combinations of BY > 0/summer and B Y < 0/winter produce the highest circular flow around the pole in comparison with the combinations of BY < 0/summer and B Y > 0/winter. The model predicts that the summer cross-polar potentials are smaller than the winter potentials. The value of the ratio depends on the combination of season/IMF BY sign. The ratio is found to be greater for the combination of BY > 0/southern summer and BY < 0/northern summer. The smallest value is obtained for the combination of BY < 0/southern summer and BY > 0/northern summer under northward IMF conditions. At middle latitudes the main features of the MLT-profile of the westward and equatorward electric field components are reproduced. The model predicts that during solstice the equatorward component of the midlatitude electric field is negative at all local times for BY < 0 and positive for BY > 0.

UR - http://www.scopus.com/inward/record.url?scp=33947657051&partnerID=8YFLogxK

U2 - 10.1029/2005JA011465

DO - 10.1029/2005JA011465

M3 - Article

AN - SCOPUS:33947657051

VL - 111

JO - Journal of Geophysical Research: Biogeosciences

JF - Journal of Geophysical Research: Biogeosciences

SN - 0148-0227

IS - 3

M1 - A03213

ER -