A statistical model of auroral ion precipitation 2. Functional representation of the average patterns

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JA02451· OSTI ID:5223415

Hardy, D A; Gussenhoven, M S; Brautigam, D ^[1]; McNeil, W ^[2]

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1. Geophysics Lab., Hanscom AFB, MA (USA)
2. Radex, Inc., Bedford, MA (USA)

In the study of Hardy et al. (1989) the average pattern of auroral ion precipitation was determined as a function of corrected geomagnetic latitude, magnetic local time (MLT), and Kp using data from the SSJ/4 detectors on the satellites of the Defense Meteorological Satellite Program (DMSP). One product of this study was a set of hemispheric maps of the integral number flux and integral energy flux of the precipitating ions for each of seven levels of activity as defined by Kp. In order to facilitate the use of these maps in magnetospheric, ionospheric, and thermospheric models, they have been fit to a functional form. To accomplish this, the latitudinal variation in the integral energy and number flux in each of 48 half-hour MLT bins of the original statistical study, for each Kp level, was fit to a general form of the Epstein function. This functional form was chosen since it fits well the asymmetric shape of the latitudinal profile of the integral energy and number flux. The Epstein function fits to the latitudinal profiles require six variables in each MLT zone. To further reduce the number of variables needed to specify a map, the MLT variation of each of the six variables was expanded as a sixth-order Fourier series with 13 coefficients. The resulting fit reproduces well the original statistical data. The distribution of differences between the original data and the fit normalized to the original data shows agreement that is generally better than 25% for both the integral energy and number flux.

• OSTI ID: 5223415
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A4; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAL ZONES
CHARGED-PARTICLE PRECIPITATION
COORDINATES
DYNAMICS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
GEOMAGNETIC COORDINATES
IONOSPHERE
MATHEMATICAL MODELS
MATHEMATICS
MECHANICS
PLANETARY IONOSPHERES
SATELLITES
STATISTICS