skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Alongshore coherence on the Pacific Northwest Continental shelf (January--April, 1975)

Abstract

During the winter and spring of 1975, current observations were made simultaneously at five locations between Tofino, British Columbia, and Newport, Oregon, a distance of 480 km. Sea level and atmospheric pressure observations were available at three locations alongshore, and wind observations, at four locations. Computed (Bakun) winds were available at 3/sup 0/ intervals. Low-frequency (<0.6 cpd) fluctuations in alongshore current, alongshore wind, and subsurface pressure were significantly coherent over this distance. Forcing by the local wind dominated the response at each location: alongshore current and sea level fluctuations were significantly coherent with the local alongshore wind, and local phase relationships were consistent with phase predicted by the local model of Hickey and Hamilton (1980). The high alongshore coherence observed in the current and subsurface pressure fluctuations is shown to be a result of alongshore coherence in the forcing, i.e., in the wind field. Moreover, although alongshore phase differences were too small to be associated with freely propagating waves, at the frequencies where alongshore coherence of the current and sea level fluctuations was strongest, the alongshore phase differences were consistent with local wind forcing. Alongshore differences in fluctuations could be directly related to alongshore structure in the wind field, providingmore » independent evidence for local wind forcing.« less

Authors:
Publication Date:
Research Org.:
Department of Oceanography, University of Washington, Seattle 98195
OSTI Identifier:
6023798
Resource Type:
Journal Article
Journal Name:
J. Phys. Oceanogr.; (United States)
Additional Journal Information:
Journal Volume: 11:6
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; PACIFIC NORTHWEST REGION; SEA LEVEL; WATER CURRENTS; CONTINENTAL SHELF; FLUCTUATIONS; PACIFIC OCEAN; WAVE PROPAGATION; WIND; CONTINENTAL MARGIN; CURRENTS; LEVELS; NORTH AMERICA; SEAS; SURFACE WATERS; USA; VARIATIONS; 580500* - Oceanography- (1980-1989)

Citation Formats

Hickey, B M. Alongshore coherence on the Pacific Northwest Continental shelf (January--April, 1975). United States: N. p., 1981. Web. doi:10.1175/1520-0485(1981)011<0822:ACOTPN>2.0.CO;2.
Hickey, B M. Alongshore coherence on the Pacific Northwest Continental shelf (January--April, 1975). United States. https://doi.org/10.1175/1520-0485(1981)011<0822:ACOTPN>2.0.CO;2
Hickey, B M. 1981. "Alongshore coherence on the Pacific Northwest Continental shelf (January--April, 1975)". United States. https://doi.org/10.1175/1520-0485(1981)011<0822:ACOTPN>2.0.CO;2.
@article{osti_6023798,
title = {Alongshore coherence on the Pacific Northwest Continental shelf (January--April, 1975)},
author = {Hickey, B M},
abstractNote = {During the winter and spring of 1975, current observations were made simultaneously at five locations between Tofino, British Columbia, and Newport, Oregon, a distance of 480 km. Sea level and atmospheric pressure observations were available at three locations alongshore, and wind observations, at four locations. Computed (Bakun) winds were available at 3/sup 0/ intervals. Low-frequency (<0.6 cpd) fluctuations in alongshore current, alongshore wind, and subsurface pressure were significantly coherent over this distance. Forcing by the local wind dominated the response at each location: alongshore current and sea level fluctuations were significantly coherent with the local alongshore wind, and local phase relationships were consistent with phase predicted by the local model of Hickey and Hamilton (1980). The high alongshore coherence observed in the current and subsurface pressure fluctuations is shown to be a result of alongshore coherence in the forcing, i.e., in the wind field. Moreover, although alongshore phase differences were too small to be associated with freely propagating waves, at the frequencies where alongshore coherence of the current and sea level fluctuations was strongest, the alongshore phase differences were consistent with local wind forcing. Alongshore differences in fluctuations could be directly related to alongshore structure in the wind field, providing independent evidence for local wind forcing.},
doi = {10.1175/1520-0485(1981)011<0822:ACOTPN>2.0.CO;2},
url = {https://www.osti.gov/biblio/6023798}, journal = {J. Phys. Oceanogr.; (United States)},
number = ,
volume = 11:6,
place = {United States},
year = {Mon Jun 01 00:00:00 EDT 1981},
month = {Mon Jun 01 00:00:00 EDT 1981}
}