Deepening of the wind-mixed layer

A model is given that describes the local response of the upper ocean to an imposed surface wind stress and heat flux…

Circulation in a wind-swept and cooled ocean

A two-layer model of circulation is developed in an open-ocean basin where a vertically homogeneous layer overlays a thermoclinic region. In the latter, the temperature changes in an exponential manner to a constant abyssal value. The motions are driven by an Ekman suction and cooling (or heating) of the ocean surface...

Seasonal variability of the Florida Current

The seasonal variability of the directly measured transport and horizontal currents in the Florida Strait has been determined from 90 transects of the Florida Current at the latitude of Miami, Florida. It is estimated that the seasonal variability accounts for 45% of the total variability in the total transport; the early summertime maximum value of the transport is 33.6 × 106 m3/sec, and the early winter low is 25.4 × 106 m3/sec...

Energetics of the Florida Current

During the summer of 1974, fifty free-drop transport profiles and STD/XBT profiles were carried out in the Florida Current at 14 stations along the 25°51.00\u27N latitude. From these data and from the historical free-drop data 12 km to the south, a computation is made of the energy flow from the mean current to the fluctuations over the entire cross-section of the Florida Straits. Statistically significant areas of both potential and kinetic energy conversion are computed...

Summary data report on direct measurements of circulation on West Florida continental shelf January 1973 - May 1975

Between January 1973 and May 1975, the National Science Foundation sponsored a cooperative field program of direct measurements of circulation on the continental shelf of the west coast of the Florida peninsula. With a variety of instruments, records of ocean currents, bottom pressure, coastal sea level and winds over the shelf were compiled, some of which are continuous for nearly two years

A compilation of observations from moored current meters and associated oceanographic observations : POLYMODE Array III Cluster C, May 1977 - May 1978

A summary of the observations taken from moored stations and hydrographic surveys in POLYMODE Array III Cluster C is presented. Currents and water temperatures were measured at various depths, including: 150, 225, 300, 500, 750, 1500, 2500, and 4000 meters. Hydrographic surveys were made during the deployment and recovery cruises. Currents and water temperature data series cover the period from mid May, 1977 to early May, 1978. Cluster C contained 4 moorings, centered about 16°N, 54°W. Basic statistics of the raw time series data are tabulated. Low passed (3.9 day cutoff) daily time series are used to display: water temperature data, velocity stick diagrams, progressive vector diagrams, zonal and meridional eddy heat flux, eddy kinetic energy, a pseudo eddy potential energy, empirical orthogonal modes, and auto-correlations. Hourly data (low pass cutoff at 2 hours) is used to display spectral quantities. Hydrographic data, including 1600 stations from the N0DC archives, are used to display T-S diagrams, horizontal and vertical structure of temperature, salinity, and density, Brunt-Viasala frequency versus depth, and dynamic topography

Eddy induced Kuroshio intrusions onto the continental shelf of the East China Sea

The Kuroshio is known to intrude onto the continental shelf in the southern East China Sea (ECS) northeast of Taiwan. Two types of intrusions are observed: large and small, depending on how far the Kuroshio penetrates onto the ECS continental shelf, and on the location where it crosses the shelf break. This study demonstrates that cyclonic eddies from the western Pacific induce some of these large Kuroshio intrusions. The large intrusions are identified from more than 20 years of drifter tracks archived in the Global Drifter Program historical database and from weekly and biweekly drifter deployments carried out between April 2008 and September 2009 west of the Green Island (Taiwan). Kuroshio intrusions are observed in all seasons. Cyclonic mesoscale eddies, generated in the Subtropical Countercurrent and North Equatorial Current regions of the northwest Pacific Ocean, propagate westward into the Kuroshio and are well correlated with the observed intrusions. During the intrusions, the mean sea level anomaly computed from AVISO gridded maps shows a well-defined cyclonic circulation southeast of the I-Lan ridge. The mean sea level anomaly also shows the meandering pattern of the Kuroshio when it intrudes onto the continental shelf of the southern East China Sea. The high correlation between the Kuroshio volume transport in the East Taiwan Channel (observed with moorings) and the satellite sea level anomaly permits us to use sea level anomaly as a proxy for the Kuroshio volume transport. When direct transport measurements are not available, this proxy is used to verify that intrusions due to the westward propagating eddies occur when the Kuroshio transport is low. An analytical reduced gravity model of an incident baroclinic current upon a step shelf is used to explain the difference between the large and small intrusions

FRONTS 80 : preliminary results from an investigation of the wintertime North Pacific subtropical front

The FRONTS-80 experiment is a joint investigation supported by the Office of Naval Research (ONR) as the lead agency with additional contributions from the National Oceanic and Atmospheric Administration (NOAA), the National Space Administration (NASA), the U.S. Navy and the Canadian Forces. Support from these agencies is gratefully acknowledged. We also gratefully acknowledge the assistance and cooperation provided by the officers and crews of the NOAA Ship OCEANOGRAPHER, the R/V THOMAS WASHINGTON, the HMCS PROVIDER, the HMCS GATINEAU, the HMCS KOOTENAY, the HMCS RESTIGOUCHE and the aircraft of the Commander Patrol Wing Two, U.S. Navy. It should be emphasized that this report is preliminary. It is a report of the observational phase of FRONTS-80 and preliminary results from individual investigators. The report is intended to aid and encourage an integrated analysis of the observations. Individual contributions should not be referenced without consent of the authors. Investigators are expected to provide more comprehensive reports and publications which will. be suitable for referencing. Specific acknowledgment of support by agency and grant or contract number will be given in these reports and publications

Altimeter-derived variability of surface velocities in the California Current System : 1. Evaluation of TOPEX altimeter velocity resolution

In this paper, we evaluate the temporal and horizontal resolution of geostrophic surface velocities calculated from TOPEX satellite altimeter heights. Moored velocities (from vector-averaging current meters and an acoustic Doppler current profiler) at depths below the Ekman layer are used to estimate the temporal evolution and accuracy of altimeter geostrophic surface velocities at a point. Surface temperature gradients from satellite fields are used to determine the altimeter's horizontal resolution of features in the velocity field. The results indicate that the altimeter resolves horizontal scales of 50-80 km in the along-track direction. The rms differences between the altimeter and current meters are 7-8 cm s⁻¹, much of which comes from small-scale variability in the oceanic currents. We estimate the error in the altimeter velocities to have an rms magnitude of 3-5 cm s⁻¹ or less. Uncertainties in the eddy momentum fluxes at crossovers are more difficult to evaluate and may be affected by aliasing of fluctuations with frequencies higher than the altimeter's Nyquist frequency of 0.05 cycles d⁻¹, as indicated by spectra from subsampled current meter data. The eddy statistics that are in best agreement are the velocity variances, eddy kinetic energy and the major axis of the variance ellipses. Spatial averaging of the current meter velocities produces greater agreement with all altimeter statistics and increases our confidence that the altimeter's momentum fluxes and the orientation of its variance ellipses (the statistics differing the most with single moorings) represent well the statistics of spatially averaged currents (scales of 50-100 km) in the ocean. Besides evaluating altimeter performance, the study reveals several properties of the circulation in the California Current System: (1) velocity components are not isotropic but are polarized, strongly so at some locations, (2) there are instances of strong and persistent small-scale variability in the velocity, and (3) the energetic region of the California Current is isolated and surrounded by a region of lower energy starting 500-700 km offshore. This suggests that the source of the high eddy energy within 500 km of the coast is the seasonal jet that develops each spring and moves offshore to the central region of the California Current, rather than a deep-ocean eddy field approaching the coast from farther offshore