Critical evaluation of the AE indices

Technical Report · Sun Jan 01 00:00:00 EST 1989

OSTI ID:6990765

Kroehl, H W

The computation of the total eastward and westward auroral electrojets from numerical modeling techniques for three different intervals during disturbed conditions provides a unique opportunity to evaluate the accuracy of the standard Auroral Electrojet indices AU(12) and AL(12). The effect on the indices of replacing the local magnetic coordinate system with a global system, of increasing the latitudinal coverage by increasing the number of stations from 12 to 57, and of integrating the current density to obtain the total current is considered as new indices are correlated with the standard ones. We conclude that AL(12) is a reasonable measure of the westward electrojet current in a statistical sense, that Au(12) is not as good a measure of the eastward current, and that values of AU(12) and AL(12) during quiet conditions, i.e., less than 50 nT, must be treated separately from disturbed conditions. It should also be noted that a rotation of the perturbation vectors into a global coordinate system improves the indices more than an increase in the number of stations. Reprints. (rrh)

• Research Organization: National Oceanic and Atmospheric Administration, Boulder, CO (USA). Environmental Research Labs.
• OSTI ID: 6990765
• Report Number(s): AD-A-216755/9/XAB
• Resource Relation: Other Information: Pub. in Jnl. of Geomagnetism and Geoelectricity, Vol. 41, 317-329(1989)
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
ELECTROJETS
INDEXES
ACCURACY
COORDINATES
CURRENT DENSITY
EVALUATION
GLOBAL ASPECTS
MAGNETIC FIELDS
MATHEMATICAL MODELS
NUMERICAL SOLUTION
CURRENTS
DOCUMENT TYPES
ELECTRIC CURRENTS
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena