Mathematical representation of the auroral oval
Article first published online: 7 DEC 2012
Copyright 1975 by the American Geophysical Union.
Geophysical Research Letters
Volume 2, Issue 9, pages 377–380, September 1975
How to Cite
(1975), Mathematical representation of the auroral oval. Geophysical Research Letters, 2: 377–380. doi: 10.1029/GL002i009p00377
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 14 AUG 1975
- Manuscript Received: 3 JUL 1975
A curve fitting procedure for mathematically representing the auroral oval is described. It is shown that the Feldstein ovals and quiet auroral ovals of the night side in DMSP photographs can be approximated by an offset circle, plus a small (≲ 1° magnitude) Fourier component in corrected geomagnetic coordinates. Parameters are introduced, Θ and (θo, ϕo), that indicate the dynamic motion of the auroral oval size and center location, respectively. Using the parameter Θ, an analysis of several DMSP photographs shows a strong correlation between the southward interplanetary magnetic field (−Bz) and the size of the auroral oval.