Variations of zonal anomalies of atmospheric excitation functions for polar motion during 1983-1999

Author: J. Nastula and David Salstein
Date: 
November 4, 2002
Type: 
Journal Article
Venue: 
Proceedings, Journees de geophysique
Citation: 

Nastula, J., B. Kolaczek, and D. Salstein, 2002: Variations of zonal anomalies of atmospheric excitation functions for polar motion during 1983-1999, Proceedings, Journees de geophysique, Royal Observatory of Belgium, Brussels, Belgium.

The pressure term of atmospheric excitation function for polar motion and monthly anomalies of its equatorial components χ1 and χ2 are computed in equal area belts for the 17 years from 1983 to 1999. The variance of the excitation maximizes in the middle to higher latitude belts of both hemispheres. In the case of equatorial component χ1 of this excitation function there are distinct annual oscillations in the north. In the χ2 component there are distinct disturbances in the south coinciding with La Nina phenomena in 1988, 1992, 1998. The variation in the overall amplitude of the excitation, from a combination of the χ1 and χ2 terms, maintains a distinctly annual oscillation in the north and La Nina disturbances in the south in its signature.