Effects of dynamic long-period ocean tides on changes in Earth's rotation rate

Journal Article · Thu May 10 00:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JB095iB05p06751· OSTI ID:5036069

Nam, Y S; Dickman, S R ^[1]

---

1. State Univ. of New York, Binghamton (United States)

As a generalization of the zonal response coefficient first introduced by Agnew and Farrell (1978), the authors define the zonal response function k of the solid earth-ocean system as the ratio, in the frequency domain, of the tidal change in Earth's rotation rate to the tide-generating potential. Amplitudes and phases of k for the monthly, fortnightly, and 9-day lunar tides are estimated from 2 1/2 years of very long baseline interferometry UTI observations (both 5-day and daily time series), corrected for atmospheric angular momentum effects using NMC wind and pressure series. Using the dynamic ocean tide model of Dickman (1988a, 1989a), the authors predict amplitudes and phases of k for an elastic earth-ocean system. The predictions confirm earlier results which found that dynamic effects of the longer-period ocean tides reduce the amplitude of k by about 1%. However, agreement with the observed k is best achieved for all three tides if the predicted tide amplitudes are combined with the much larger satellite-observed ocean tide phases; in these cases the dynamic tidal effects reduce k by up to 8%. Finally, comparison between the observed and predicted amplitudes of k implies that anelastic effects on Earth's rotation at periods less than fortnightly cannot exceed 2%.

• OSTI ID: 5036069
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:B5; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
EARTH PLANET
ROTATION
TIDE
FLUID MECHANICS
AMPLITUDES
ANGULAR MOMENTUM
ATMOSPHERIC PRESSURE
GENERAL CIRCULATION MODELS
INTERFEROMETRY
OCEANIC CIRCULATION
RESPONSE FUNCTIONS
SEAS
VARIATIONS
WIND
FUNCTIONS
MATHEMATICAL MODELS
MECHANICS
MOTION
PLANETS
SURFACE WATERS
540310* - Environment
Aquatic- Basic Studies- (1990-)
580000 - Geosciences