Article
 

Diurnal/semidiurnal polar motion excited by oceanic tidal angular momentum

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/st74cw45b

Descriptions

Attribute NameValues
Creator
Abstract
  • The axial component of the oceanic tidal angular momentum (OTAM) has been demonstrated to be responsible for most of the diurnal and semidiurnal variations in Earth's rotational rate. In this paper we study the equatorial components of OTAM and their corresponding effects on the orientation of Earth's rotational axis, or polar motion. Three ocean tide models derived from TOPEX/Poseidon satellite altimetry are employed to predict the polar motion excited by eight major diurnal/semidiurnal tides (Q₁,O₁,P₁, K₁, N₂, M₂, S₂, K₂). The predictions are compared with geodetic measurements of polar motion from both long‐term observations and during the intensive campaign Cont94. The prograde diurnal and prograde and retrograde semidiurnal periods are treated, whereas the retrograde diurnal polar motion is not treated (because it cannot be observed directly and uniquely.) The comparison shows generally good agreement, with discrepancies typically within 10–30 micro‐arc‐ seconds for the largest tides. The eight tides collectively explain nearly 60% of the total variance in subdaily polar motion during Cont94. This establishes the dominant role of OTAM in exciting the diurnal/semidiurnal polar motion and paves the way for detailed studies of short‐period nontidal polar motion. The present accuracy, however, is inadequate to shed light on the prograde diurnal polar libration.
Resource Type
DOI
Date Available
Date Issued
Citation
  • Chao, B. F., Ray, R. D., Gipson, J. M., Egbert, G. D., & Ma, C. (1996). Diurnal/semidiurnal polar motion excited by oceanic tidal angular momentum. Journal of Geophysical Research, 101(B9), 20151-20163.
Journal Title
Journal Volume
  • 101
Journal Issue/Number
  • B9
Rights Statement
Funding Statement (additional comments about funding)
  • NASA Geophysics Program
Publisher
Language
Replaces

Relationships

Parents:

This work has no parents.

Items

Thumbnail Title Date Uploaded Visibility Actions
file details Chao_et_al_JGR_1996.pdf 2017-12-06 Public Download