Empirical plasmapause models from magnetic indices

[1] We use a database of CRRES in situ observations of plasmapause crossings to build empirical models of the plasmapause location as a function of geomagnetic indices. Previous models used the maximum value in Kp during the hours to days leading up to the plasmapause crossing. We find that a recent maximum in AE or minimum in Dst provides a better model of the plasmapause radius than does maximum Kp. AE and Dst measure specific current systems (the auroral electrojet and ring current, respectively). The AE model suggests that substorms may be involved in the erosion of the plasmapause. The Dst model suggests that ring current may be formed by the same electric field that erodes the plasmapause. In more complex models, Kp and AE can describe local time structure in the plasmapause, with the furthest plasmapause before dawn at quiet times, premidnight at active times.

[1]  A. Nishida Formation of plasmapause, or magnetospheric plasma knee, by the combined action of magnetospheric convection and plasma escape from the tail , 1966 .

[2]  P. Mayaud,et al.  Derivation, Meaning, and Use of Geomagnetic Indices , 1980 .

[3]  R. Anderson,et al.  An ISEE/Whistler model of equatorial electron density in the magnetosphere , 1992 .

[4]  S. Akasofu,et al.  Low-latitude DS component of geomagnetic storm field , 1971 .

[5]  F. A. Seiler,et al.  Numerical Recipes in C: The Art of Scientific Computing , 1989 .

[6]  C. E. Rasmussen,et al.  Interaction of ring current and radiation belt protons with ducted plasmaspheric hiss: 2. Time evolution of the distribution function , 1995 .

[7]  W. P. Olson Quantitative modeling of magnetospheric processes , 1979 .

[8]  K. R. Lorentzen,et al.  Observations of relativistic electron microbursts in association with VLF chorus , 2001 .

[9]  Mark B. Moldwin,et al.  A new model of the location of the plasmapause: CRRES results , 2002 .

[10]  Aaron J. Ridley,et al.  A model‐derived storm time asymmetric ring current driven electric field description , 2002 .

[11]  Richard M. Thorne,et al.  Potential waves for relativistic electron scattering and stochastic acceleration during magnetic storms , 1998 .

[12]  William H. Press,et al.  The Art of Scientific Computing Second Edition , 1998 .

[13]  G. W. Sharp,et al.  A study of the influence of magnetic activity on the location of the plasmapause as measured by OGO 5 , 1970 .