Wind-Current Relationships in the Optoma Domain Off the Northern California Coast.
Abstract
The oceanic response to time-dependent wind forcing approximately 100-200 km off the Northern California coast is examined through cross-spectrum analysis of current and wind time series. Current meter records 10 months in length from three moorings in deep water 100-200 km off the coast are analyzed in conjunction with surface wind analyses from the Fleet Numerical Oceanography Center. Coherence is found between atmospheric and oceanic variables in the 'locally forced' band (1-10 day period), in the 'planetary wave' band (10-30 day period), and at low frequency (greater than 30 day period), though not in all of these bands for all records. The barotropic and first baroclinic dynamical modes appear to respond to wind forcing at different frequencies for two of the moorings analyzed. There is coherence between alongshore divergence and temperature fluctuations 100 km farther offshore, consistent with offshore advection by current filaments. Evidence of the Sverdrup balance is found for some periods greater than 18 days in the form of coherence between wind stress curl and the current component parallel to the local potential vorticity gradient. Complex bottom topography and the influence of coastal processes in the vicinity of the current meter moorings appear to greatly complicate the flow. There appears to be significant mesoscale variability in the region at scales too small to be resolved by the 100 km spacing of the OPTOMA moorings. Keywords: Ocean currents, North Pacific Ocean, Air water interactions. (Theses)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1986
- Accession Number
- ADA176019
Entities
People
- Steven J. Summers
Organizations
- Naval Postgraduate School