Magnetosphere Inflation due to Equatorial Ring Current
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An inflation of the magnetosphere due to the magnetic field of an equatorial ring current is estimated. It is suggested that the inflation of the magnetosphere is determined by an equivalent magnetic dipole of the ring current which is approximated by half a <I>Dst</I> variation of the geomagnetic field multiplied by a cube of an effective radius of the equatorial ring current. It is also suggested that a 100-200 nT <I>Dst</I> causes a 7-20% inflation of the dayside magnetosphere, 10-30% in the distant tail radius, and as large as 40-170% of the tail length under the constant dynamic pressure of the solar wind. In this connection, it is also shown that the <I>Dst</I> magnitude is limited below a certain value with a certain effective radius of the ring current, for example about 450 nT with the effective radius of 5 <I>R<SUB>E</SUB></I>. An increase in the flaring angle of the tail magnetopause is also expected to occur as a <I>Dst</I> field develops.
- Earth, Planets and Space
Earth, Planets and Space 47(4), 347-352, 1995-04
Society of Geomagnetism and Earth, Planetary and Space Sciences