Lunar and Solar Torques on the Oceanic Tides (Paperback) (ISBN-13: 9781289274993)

A general framework for calculating lunar and solar torques on the oceanic tides is developed in terms of harmonic constituents. Axial torques and their associated angular momentum and earth-rotation variations are deduced from recent satellite-altimeter and satellite-tracking tide solutions. Torques on the prograde components of the tide produce the familiar secular braking of the rotation rate. The estimated secular acceleration is approximately -1300 sec/century(sup 2) (less 4% after including atmospheric tides); the implied rate of change in the length of day is 2.28 milliseconds/century. Torques on the retrograde components of the tide produce periodic rotation variations at twice the tidal frequency. Interaction torques, e.g. solar torques on lunar tides, generate a large suite of rotation-rate variations at sums and differences of the original tidal frequencies. These are estimated for periods from 18.6 years to quarter-diurnal. At subdaily periods the angular momentum variations are 5 to 6 orders of magnitude smaller than the variations caused by ocean tidal currents.


Author: Nasa Technical Reports Server (Ntrs),Richard D. Ray
ISBN-10: 1289274991
ISBN-13: 9781289274993
Publisher: Bibliogov
Language: English
Published: 08/02/2013
Pages: 28
Format: Paperback
Weight: 0.15lbs
Size: 9.69h x 7.44w x 0.06d