Earth Rotation and Polar Motion: Measurements and Implications

• Published in: IEEE transactions on geoscience and remote sensing Vol. GE-23; no. 4; pp. 373 - 384
• Main Authors: Dickey, Jean O., Eubanks, T. Marshall
• Format: Journal Article
• Language: English
• Published: Legacy CDMS IEEE 01-07-1985; Institute of Electrical and Electronics Engineers
• Subjects: Active appearance model; Atmospheric measurements; Earth; Earth, ocean, space; Exact sciences and technology; External geophysics; Extraterrestrial measurements; Geodesy; Geodesy and gravity; Geophysical measurements; Geophysics; Level measurement; Motion measurement; Rotation measurement; Sea measurements; Earth rotation; Momentum transfer; Satellite geodesy; Angular momentum; Polar motion
• ISSN: 0196-2892; 1558-0644
• DOI: 10.1109/TGRS.1985.289427

Earth rotation and polar motion studies are embarking on a new era with the advent of highly accurate space geodetic techniques and the availability of global atmospheric angular momentum measurements. Space geodesy is opening new doors, answering old questions, and posing new ones. The angular momentum balance and the transfer of angular momentum between the solid Earth, atmosphere, and oceans are emerging as a problem of great scientific interest overlapping many areas, such as atmospheric science, oceanography, geodesy, and geodynamics. Here, the measurements of Earth rotation and polar motion (collectively referred to as Earth orientation) are described; the combination, smoothing, and intercomparison of these results from various techniques are presented. The calculation of atmospheric angular momentum (AAM) excitation functions are outlined; comparisons of the AAM excitation functions with variations in the length of day (LOD) and polar motion results are discussed. The associated geophysical implications (e.g., J2, 50-day oscillations) are stressed; anticipated advances and prospects for the future are high lighted.