HF radar observations of surface circulation off Bodega Bay (northern California, USA)

Kaplan, David M.; Largier, John L.; Botsford, Louis W.

doi:10.1029/2005jc002959

Cited by 117 publications

(124 citation statements)

References 52 publications

Supporting

Mentioning

104

Contrasting

Order By: Relevance

“…The present study compliments the work of who looked at the surface boundary layer response to wind forcing (from moored observations), and Kaplan et al (2005) who addressed the question of the across-shelf structure of the surface flows (derived from HF radar). In Section 3 we identify the water masses observed in the region and the mean hydrographic conditions across the shelf as measured during both the summer and winter seasons.…”

Section: Introductionmentioning

confidence: 75%

“…While elements of this pattern are evident in HF radar data (Kaplan et al, 2005), these data extend less than 45 km offshore. The offshore jet interacts with the undercurrent, with observed strengthening of the undercurrent during years of weak upwelling winds (2000) The equatorward jets typically transport colder water, more recently upwelled, but with varying levels of chlorophyll fluorescence (e.g.…”

Section: The Upwelling Jet During Westmentioning

confidence: 99%

“…The hydrography in the Gulf of the Farallones region to the south of Pt Reyes has been well documented by Steger et al (2000). Offshore and to the northwest of this headland is the submerged Cordell Bank, where the water shallows to a depth of < 90 m. The combination of the submerged bank adjacent to a significant promontory forms an interesting topographic feature which appears to affect the flow field (Kaplan et al, 2005;Kuebel-Cervantes and Allen, 2006). This is the focal point for future investigation of the effects of topography on classical upwelling circulation.…”

Section: Introductionmentioning

confidence: 99%

“…Through analysis of HF radar estimates of surface velocity, Kaplan et al (2005) found that in the surface waters, fluctuations on a sub-tidal timescale account for 45 − 75% of the variability, whilst tidal harmonics explained only 4 − 14% of the total variance in the surface velocity field. Steger et al (1998) found that in the Gulf of the Farallones region individual tidal constituents exhibit considerable spatial variability, i.e.…”

Section: Shipboard Current Profilesmentioning

confidence: 99%

“…However clear evidence of a more complicated structure is identified by the data obtained during the WEST program. Through temporal averages of HF radar measurements of the surface velocity fields in the WEST region, Kaplan et al (2005) iden-tified zones in the surface velocity structure across the shelf. Using shipboard ADCP measurements we are able to investigate the across-shelf structure of the depth-dependent flow during wind-driven upwelling and relaxation.…”

Section: The Three-dimensional Circulation Patterns Over the Shelf Anmentioning

confidence: 99%

See 4 more Smart Citations

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

Section: Introductionmentioning

confidence: 75%

Section: The Upwelling Jet During Westmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Shipboard Current Profilesmentioning

confidence: 99%

Section: The Three-dimensional Circulation Patterns Over the Shelf Anmentioning

confidence: 99%

See 3 more Smart Citations

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

show abstract

Surface circulation in the Gulf of Trieste (northern Adriatic Sea) from radar, model, and ADCP comparisons

Cosoli

Ličer

Vodopivec

et al. 2013

J. Geophys. Res. Oceans

View full text Add to dashboard Cite

[1] High resolution high frequency (HF) radar observations of surface currents in the Gulf of Trieste (GoT) are presented and compared to moored subsurface current measurements and to high-resolution simulations from the Northern Adriatic Princeton Ocean Model (NAPOM) oceanographic model. Dominant circulation modes of the GoT were resolved and numerical model capabilities in reconstructing them were assessed. The time frame covers March 2011 through October 2012. NAPOM reconstructs the dominant surface circulation features observed by the radar, such as the general basin-wide cyclonic circulation scheme and the coastal jet outflowing the GoT, but is in general less energetic than radar currents. Comparisons between radar, ADCP, and model currents suggest that the model underestimates originate within the low-frequency, diurnal, semidiurnal, and inertial bands, and that both radar and model currents do not reproduce the diurnal tidal ellipse structure observed by the moored current meter. However, radar-model results for the semidiurnal tides are spatially consistent. Using empirical orthogonal function (EOF) decomposition, the coherent spatial scales and corresponding temporal scales were extracted. Findings suggest that HF radar current observations complement model simulations in regions of enhanced topographic variability where variance of model currents at the surface is distorted by the effects of the sigma layer grid. On the contrary, model results complement radar observations in areas with poor radar coverage, and furthermore provide spatial and temporal continuity of ocean state forecasts.

show abstract

Dynamics of the Chesapeake Bay outflow plume: Realistic plume simulation and its seasonal and interannual variability

Jiang

Xia

2016

JGR Oceans

View full text Add to dashboard Cite

The three‐dimensional unstructured‐grid Finite Volume Coastal Ocean Model (FVCOM) was implemented for Chesapeake Bay and its adjacent coastal ocean to delineate the realistic Chesapeake Bay outflow plume (CBOP) as well as its seasonal and interannual variability. Applying the appropriate horizontal and vertical resolution, the model exhibited relatively high skill in matching the observational water level, temperature, and salinity from 2003 to 2012. The simulated surface plume structure was verified by comparing output to the HF radar current measurements, earlier field observations, and the MODIS and AVHRR satellite imagery. According to the orientation, shape, and size of the CBOP from both model snapshots and satellite images, five types of real‐time plume behavior were detected, which implied strong regulation by wind and river discharge. In addition to the episodic plume modulation, horizontal and vertical structure of the CBOP exhibited variations on seasonal and interannual temporal scales. Seasonally, river discharge with a 1 month lag was primarily responsible for the surface plume area variation, while the plume thickness was mainly correlated to wind magnitude. On the interannual scale, river discharge was the predominant source of variability in both surface plume area and depth; however, the southerly winds also influenced the offshore plume depth. In addition, large‐scale climate variability, such as the North Atlantic Oscillation, could potentially affect the plume signature in the long term by altering wind and upwelling dynamics, underlining the need to understand the impacts of climate change on buoyant plumes, such as the CBOP.

show abstract

HF radar observations of surface circulation off Bodega Bay (northern California, USA)

Cited by 117 publications

References 52 publications

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

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

Surface circulation in the Gulf of Trieste (northern Adriatic Sea) from radar, model, and ADCP comparisons

Dynamics of the Chesapeake Bay outflow plume: Realistic plume simulation and its seasonal and interannual variability

Contact Info

Product

Resources

About