Record Details
Field | Value |
---|---|
Title | Near-inertial motions off the Oregon coast |
Names |
Anderson, Iain
(creator) Huyer, Adriana (advisor) |
Date Issued | 1982-04-30 (iso8601) |
Note | Graduation date: 1982 |
Abstract | Nearly three months of current meter records from five moorings off the Oregon coast taken between October 1977 and January 1978 were analyzed for near-inertial motions. The moorings were located from the midshelf out to the foot of the continental slope, spanning the continental margin. All but two of the eleven current meters were continuously below the mixed layer. For spectral analysis, the current observation period was divided into two time periods, one with large amplitude near-inertial motion (41.1 cm/sec maximum of the band-passed records) throughout and the other with much less near-inertial energy. The spectra of the current meter records showed between a 1 and 6% increase in frequency of the near-inertial peak above f (= 0.0592 cph) in all but three cases. The exceptions showed spectral peaks about 14% below f and were linked to a Doppler shift. The period of large amplitude near-inertial motion had diagonal coherence scales of over 450 meters vertically and 115 kilometers horizontally. An east-west (cross-shelf) wavelength of about 50 kilometers was estimated directly from the phase differences between current meters with roughly horizontal separations. The observed response of a current meter about 35 meters below the mixed layer to sharp maxima in the wind stress was similar to that predicted by the Pollard and Millard (1970) model for wind forced near-inertial motions in the surface mixed layer. The winds associated with a series of atmospheric fronts were apparently responsible for generating a 14-day period of large amplitude near-inertial motion observed below the mixed layer. |
Genre | Thesis/Dissertation |
Topic | Ocean currents -- Pacific Ocean |
Identifier | http://hdl.handle.net/1957/27706 |