On the excitation of the Earth' polar motion
- 1 August 1985
- journal article
- Published by American Geophysical Union (AGU) in Geophysical Research Letters
- Vol. 12 (8) , 526-529
- https://doi.org/10.1029/gl012i008p00526
Abstract
One of the conclusions reached by recent studies of Barnes et al. and later Hide was “that atmospheric excitation alone was sufficient to account for the observed polar motion over (the studied) period, that there is apparently no need to invoke substantial excitation either by the fluid core or …earthquakes.” The purpose of the present paper is to point out that their argument that led to the above conclusion is unjustifiable (hence whether the conclusion is in reality true or not is still an open question). I demonstrate this through a physical “thought” experiment and a numerical simulation. In essence, they show that if we want to compare a geophysically observed excitation function ψa(t) with the excitation function deduced (via deconvolution) from the polar motion observation m(t), we should do so directly (the “direct approach”). To compare m(t) with the polar motion computed (via convolution) from ψa( t) (the “integration approach”), as Barnes et al. and Hide did, is misleading.This publication has 5 references indexed in Scilit:
- Rotation of the atmospheres of the Earth and planetsPhilosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1984
- Atmospheric angular momentum fluctuations, length-of-day changes and polar motionProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1983
- The Earth's Variable RotationPublished by Cambridge University Press (CUP) ,1980
- Earthquakes, weather and wobbleGeophysical Research Letters, 1977
- Excitation of the Chandler wobble by large earthquakesNature, 1976