Articles | Volume 15, issue 12
https://doi.org/10.1007/s00585-997-1532-x
https://doi.org/10.1007/s00585-997-1532-x
31 Dec 1997
31 Dec 1997

Erosion of the inner magnetosphere during geomagnetic storms

E. Y. Feshchenko and Y. P. Maltsev

Abstract. Using the empirical magnetic field model dependent on the Dst index and solar wind dynamic pressure, we calculated the behaviour of the contour B = Bs in the equatorial plane of the magnetosphere where Bs is the magnetic field in the subsolar point at the magnetopause. The inner domain of the magnetosphere outlined by this contour contains the bulk of geomagnetically trapped particles. During quiet time the boundary of the inner magnetosphere passes at the distance ~10 RE at noon and at ~7 RE at midnight. During very intense storms this distance can be reduced to 4–5 RE for all MLT. The calculation results agree well with the satellite measurements of the magnetopause location during storms. The ionospheric projection of the B = Bs contour calculated with the Euler potential technique is close to the equatorward edge of the auroral oval.