Tidal band current variability over the Northern California continental shelf

Rosenfeld, Leslie K.

doi:10.1575/1912/3931

Cited by 11 publications

(9 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Applying a critical value of a/R to observed tidal data, he reported that the baroclinic tidal currents were bottom intensified as a/R > 1. Similar features were also reported by Rosenfeld (1987) in the moored current meter data over the northern California continental shelf where the kinetic energy of the observed semidiurnal internal tide was concentrated in the first baroclinic mode and increased as stratification became strong.…”

Section: N2supporting

confidence: 85%

“…It is interesting to compare the structure of the model-predicted internal tide with observations and theories. There has been much observational work done on the internal tidal waves over Georges Bank, the Nova Scotian, Australian, and California shelves (Trites, 1978;Moody et al, 1984;Marsden, 1986;Loder et al, 1992;Petrie, 1974;Holloway, 1983Holloway, , 1984Holloway, , 1985Winant and Olson, 1976;Winant, 1979;Rosenfeld, 1987 Moody et al (1984) and later by Loder et al (1992). Holloway (1983 and conducted a relatively long term current meter measurement on the northwestern Australian shelf and found that the vertical structure of the internal tide was primarily dominated by the first baroclinic mode, which decreased in amplitude as stratification was reduced.…”

Section: N2mentioning

confidence: 99%

See 1 more Smart Citation

Variability of currents in Great South Channel and over Georges Bank : observation and modeling

Chen¹

1992

View full text Add to dashboard Cite

Section: N2supporting

confidence: 85%

Section: N2mentioning

confidence: 99%

Variability of currents in Great South Channel and over Georges Bank : observation and modeling

Chen¹

1992

View full text Add to dashboard Cite

“…the tides change from mixed to diurnal across the shelf. Rosenfeld (1987) investigated the structure of the internal tide in the region and found that it varied in magnitude depending on the phase of the wind cycle (upwelling or relaxation) when stratification was either weaker or stronger. The amplitudes ranged 5 − 10 cms −1 over the shelf with some surface intensification up to 20cms −1 during periods of relaxation.…”

Section: Shipboard Current Profilesmentioning

confidence: 99%

Transport and retention in an upwelling region: The role of across-shelf structure

Roughan

Garfield

Largier

et al. 2006

Deep Sea Research Part II: Topical Studies in Oceanography

View full text Add to dashboard Cite

The paradox of upwelling is the relationship between strong wind forcing, nutrient enrichment and shelf productivity. Here we investigate how across-shelf structure in velocity and hydrography plays a role in the retention (inshore) and export (offshore) of particles such as nutrients, plankton and larvae.We examine the spatial structure of the coastal currents during wind-driven upwelling and relaxation on the northern Californian Shelf. The field work was conducted as part of the Wind Events and Shelf Transport (WEST) project, a 5-year NSF/CoOP-funded study of the role of wind-driven transport in shelf productivity off Bodega Bay (northern California) from 2000 − 2003. We combine shipboard velocity profiles (ADCP) and water properties from hydrographic surveys during the upwelling season to examine the mean across-shelf structure of the hydrography and velocity fields during three contrasting upwelling seasons, and throughout the upwelling-relaxation cycle. We also present results from two winter seasons which serve as contrast to the upwelling seasons.During all three upwelling seasons clear spatial structure is evident in velocity and hydrography across the shelf, exemplified by current reversals inshore and the presence of a persistent upwelling jet at the shelf break. This jet feature changes in structure and distance from the coast under different wind forcing regimes. The jet also changes from the north of our region where it is a single narrow jet, adjacent to the coast and to the south of our region where it broadens and at times two jets become evident. We present observations of the California Under Current which was observed at the outer edge of our domain during all three upwelling seasons. The observed across-shelf structure could aid both in the retention of plankton inshore during periods of upwelling followed by relaxation and in the export of plankton offshore in the upwelling jet.

show abstract

“…Former studies suggest that both the diurnal wind stress and the surface heat flux play an important role in the diurnal response of the surface boundary layer (Rosenfeld, 1987). The subtidal variability was discussed by Lentz (1992).…”

Section: Diurnal Variabilitymentioning

confidence: 99%

“…A good linear regression can be obtained, which shows that strong winds correspond to thick surface mixed layers. Rosenfeld (1987) suggested that the surface heat flux drives a diurnal variation in the surface mixed layer depth. But Lentz (1992) obtained opposite re- When the influence of the wind stress is removed using a linear, multiple regression analysis, there is no significant relationship between the sub-tidal surface heat flux variability and the surface mixed layer depth variability.…”

Section: Subtidal Variabilitymentioning

confidence: 99%

The upper mixed layer during coastal upwelling events on the northern portugal shelf

Zuo

Peliz²,

Miguel³

2003

J Ocean Univ. China

View full text Add to dashboard Cite

The upper mixed layer (UML) depth obtained from temperature is very close to that from density:the maximum is about 15 m. This indicates that temperature is a good indicator of mixed layer during measurements. When the surface heat flux is balanced by a cross-shore heat flux, the surface mixed layer depth obtained from the WM model (Weatherly and Martin, 1978), hers, is roughly the same as observed. The mixed layer depth calculated from the PWP model (Price, Weller and Pinkel, 1986) is close to the depth obtained from thermistor chain temperature data. The results show that both the WM model and PWP model can provide a good estimate of stratification in the study area during the cruise. The value of log (h~ u 3 ) is about 9.5 in the study area, which shows that the study area is strongly stratified in summer. Observations on the northern Portugal shelf reveal high variability in stability, giving rise to semi-diurnal, semi monthly and diurnal oscillations, and long term variations. The fortnightly oscillations are highlighted by post-springs and post-neaps. The stirring of spring tide is reinforced by strong wind mixing which brings about complete vertical homogeneity everywhere. The semi-diurnal periodic stratification is very pronounced because the major axis of the tidal ellipse is orientated acrossshore, even though the tidal current is weak in this area, the maximum stratification is observed around the middle of ebb, and, the water at this time is much warmer. The diurnal oscillation results from the upper ocean response to heating and wind mixing when solar heating warms and stabilizes the upper ocean. There is a clear relationship between upper mixed layer depth and wind-stress magnitude at subtidal frequencies. Stronger winds result in a deeper surface mixed layer. Typically, the surface mixed layer depth lags the wind stress by 6 12 h.

show abstract

Tidal band current variability over the Northern California continental shelf

Cited by 11 publications

References 30 publications

Variability of currents in Great South Channel and over Georges Bank : observation and modeling

Variability of currents in Great South Channel and over Georges Bank : observation and modeling

Transport and retention in an upwelling region: The role of across-shelf structure

The upper mixed layer during coastal upwelling events on the northern portugal shelf

Contact Info

Product

Resources

About