Analysis of Monterey Bay CODAR-derived Surface Currents, March to May 1992
Author: Thomas C. Neal
Publisher:
Published: 1992
Total Pages: 118
ISBN-13:
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Analysis of Monterey Bay CODAR-Derived Surface Currents, March to May 1992
Author:
Publisher:
Published: 1900
Total Pages:
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DOWNLOAD EBOOKEvolution of Diurnal Surface Winds and Surface Currents for Monterey Bay
Author: Michael D. Foster
Publisher:
Published: 1993
Total Pages: 114
ISBN-13:
DOWNLOAD EBOOKThe diurnal-period fluctuations of winds and surface currents are analyzed for September 1992 in and around Monterey Bay. Wind records are compared for three coastal stations and two mooring sites. Remotely-sensed surface current observations from two CODAR (HF radar) sites are used to explore the ocean's response to diurnal-period forcing. An average diurnal cycle is formed at each wind station and at all CODAR bins. The earliest sea breeze response is seen at the coastal wind stations where morning winds accelerate toward the coastal mountain ranges. A few hours later, the coastal winds accelerate to the southeast down the Salinas Valley. Offshore afternoon winds rotate from their normal alongshore orientation to also become aligned with the valley. The CODAR-derived surface currents respond in less than the two-hour sampling rate to the onset of the diurnal onshore winds. Currents accelerate in the direction of the Salinas Valley. As the day progresses, the more offshore currents rotate clockwise out from under the winds in a possible Ekman or inertial adjustment that continues throughout the night and spreads onshore. In the afternoon, a complicated eddy pattern develops near shore in a possible response to the coastal boundary.
Characterization of Tidal Currents in Monterey Bay from Remote and In-situ Measurements
Author: Emil T. Petruncio
Publisher:
Published: 1993
Total Pages: 124
ISBN-13:
DOWNLOAD EBOOKA first order description of tidal heights and currents in Monterey Bay is provided. Analysis of sea level records indicate that a mixed, predominantly semidiurnal tide nearly co-oscillates within the bay. Analysis of month-long moored ADCP records obtained in the winter and summer of 1992 reveals that tidal-band currents account for approximately 50 percent of the total current variance in the upper ocean (20-200 m). A relatively strong (7 cm/s) fortnightly tide (MSf) is present in both seasons. Considerable rotation of the semidiurnal ellipse orientations occurs with depth during both seasons. A month- long record of surface current measurements obtained with CODAR, an HF radar system, during September 1992 reveals that the Monterey Submarine Canyon clearly influences the strength and direction of semidiurnal (M2) tidal currents. Good agreement exists between the strength and orientation of ADCP- and CODAR-derived tidal ellipses, with the exception of the constituent K1. Large, spatially uniform K1 surface currents (20-30 cm/s) appear to be the result of diurnal sea breeze forcing.
A Study of Time Variability of Surface Currents at a Point in Monterey Bay
Author: Harry M. Howton
Publisher:
Published: 1972
Total Pages: 236
ISBN-13:
DOWNLOAD EBOOKThe geomagnetic electrokinetograph (GEK) was used to measure surface currents near the center of Monterey Bay during six separate 24-hour periods from May through July, 1972. An average of 244 current vectors were derived for each cruise. The mean currents from these cruises are all southerly and ranged from 4.1 cm/sec to 20.4 cm/sec. The average of these mean currents is 12.1 cm/sec toward 163T. These values were compared with individual currents derived from dynamic topographies from the same period. Diurnal and semi-diurnal variations of the current were studied after subjecting the data to a Fourier analysis. It was concluded that there must be at least an indirect coupling of the ocean currents with the semi-diurnal tide at the data point. The diurnal component also is important; it may be tidal or inertial, or merely related to the passage of the sun. (Author).
Measurements of Ocean Currents Across the Continental Margin Off Point Sur, California, During March 1989
Author: Anthony J. Negron
Publisher:
Published: 1993
Total Pages: 100
ISBN-13:
DOWNLOAD EBOOKMean currents and density were measured off Point Sur, California in March 1989 using Pegasus and CTD instruments. Velocity, temperature, salinity, and density fields are examined to discern the structure of the California and Davidson currents. Velocities measured by Pegasus are compared to flow fields derived from geostrophy. The Davidson Current flows poleward at the surface in its winter configuration despite northerly winds and coastal upwelling which normally drive the flow subsurface in the summer months.
Study of Time Variability of Surface Currents at a Point in Monterey Bay
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Published:
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DOWNLOAD EBOOKCharacterization of OSCR HF Radar Data in Monterey Bay
Author: Kimberley F. Boyer
Publisher:
Published: 1997
Total Pages: 108
ISBN-13:
DOWNLOAD EBOOKA 53-hour long record of surface current data from the OSCR HF radar system was gathered over Monterey Bay on 6-8 May, 1995. In this study, OSCR data is evaluated with regard to semi-diurnal (M2) and diurnal (K1) tidal period fluctuations, the seabreeze, seabreeze influenced flow, and both standard and cannonical-day mean flow patterns. The OSCR data is considered on its own and in comparison to similar data types previously gathered by CODAR, a previously established Monterey Bay HF radar system. Two of three CODAR sites were co- located with the two OSCR sites. Internal wave influence is observed in the M2 tidal constituent analysis and the seabreeze greatly influences fluctuations of the K1 tidal period. Results from analysis of OSCR data replicated or reinforced data and results from the CODAR system. Initial OSCR data appears not to have been significantly affected by possible distortion of the phased-array beam patterns. However, contamination of OSCR returns by simultaneous activation of the CODAR systems is apparent in the data.
An Investigation of Surface Current Patterns Related to Upwelling in Monterey Bay, Using High Frequency Radar
Author: Andres Enriquez
Publisher:
Published: 2004-06-01
Total Pages: 101
ISBN-13: 9781423518105
DOWNLOAD EBOOKHigh Frequency (HF) radar backscatter instruments are under development and testing in the marine science and defense science communities for their abilities to remotely sense surface parameters in the coastal ocean over large areas. In the Navy context, the systems provide real-time mapping of ocean surface currents and waves critical to characterization and forecasting of the battlespace environment. In this study, HF radar, aircraft and satellite information were used to investigate and describe surface current in Monterey Bay, California, for a period of ten months, from June 1, 2003 to March 31, 2004. A network of five CODAR-type HF radar instruments measured hourly surface currents over the bay. The measurements were averaged over one-hour intervals and total surface velocities were mapped on a grid in the Monterey Bay. Major upwelling events were observed during the period of June 14 to June 27, July 4 to July 19, August 8 to August 18 and other upwelling events were observed until late October. These periods of upwelling favorable winds are common during summer with durations of 10 to 20 days. Cyclonic circulation cells are developed on shore during upwelling conditions and an anticyclonic circulation in the middle of the bay is observed when the wind shifts to the southwest producing a strong flow out of the bay close to the coastline off Point Pi os. Downwelling conditions are much less common than upwelling, with occurrences during winter and early fall storms with events lasting between two to five days. When the wind blows to the northeast with an intensity of 4 m/s or more for more than 12 hours, a well developed anticyclonic gyre forms in the middle of the bay. This is associated with a strong current, 35 to 40 cm/s, which flushes out in the southern part of the bay close to the coast off Point Pi os. This flow reverses when the winds veer to the southwest and enter into the Bay with less intensity.
Climatology and Analysis of the Monterey Bay Sea Breeze
Author: Robert D. Round
Publisher:
Published: 1993
Total Pages: 126
ISBN-13:
DOWNLOAD EBOOKSea breeze events on the Monterey Bay are examined from a single station at the mouth of the Salinas Valley. Data analyzed are continuous, two- minute meteorological samples of windspeed, wind direction, temperature, dew point, incoming shortwave irradiance, and incoming longwave irradiance. A speed index is defined using the average hourly maximum and minimum windspeeds oriented in the cross-shore direction thereby reflecting the thermally induced diurnal windspeed enhancement. Large-scale effects on this mesoscale circulation are presented through evaluation of changes in boundary layer depth with changes in speed index. Changes in boundary layer depth as reflected in trends of inland stratus penetration and offshore flow provide insight for anticipating sea breeze intensity.
