Do Platforms Off California Reduce Bocaccio Recruitment 

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FINAL TECHNICAL SUMMARY 

STUDY TITLE: Observations of the surface circulation in the eastern Santa Barbara 

Channel using high frequency radar and Lagrangian drifters. 

REPORT TITLE: Do platforms off California reduce recruitment of bocaccio (Sebastes 

paucispinis) to natural habitat? An analysis based on trajectories derived from high-frequency 

radar. 

CONTRACT NUMBER: 14-35-0001-31063 

SPONSORING OCS REGION: Pacific 

APPLICABLE PLANNING AREA(S): Southern California 

FISCAL YEAR(S) OF PROJECT FUNDING: FY 02, FY 03, FY 04, FY 05 

COMPLETION DATE OF REPORT: October 2006 

COSTS: FY 02-04 – $135,210; FY 05 – no cost extension 

CUMULATIVE PROJECT COST: $135,210 

PROJECT MANAGER: Russell J. Schmitt

AFFILIATION: Coastal Research Center, Marine Science Institute, University of 

California, Santa Barbara, CA 93106 

ADDRESS: University of California, Santa Barbara, CA 93106 

PRINCIPAL INVESTIGATOR: Libe Washburn 

ADDRESS: Department of Geography, University of California, Santa Barbara, CA 

KEY WORDS: surface circulation, Lagrangian drifter, Santa Barbara Channel, radar array, 

radar sites and hardware 

BACKGROUND: 

Since 1998, Principal Investigator Washburn’s research group has been operating an array of HF 

radars in the Santa Barbara Channel. During the period of this study (25 September 2002 – 30 

September 2004; no-cost extension until 30 September 2005), a total of 2-4 radar sites was 

maintained along the mainland coast of the Channel. The configuration of the array as of 13 

June 2006 is shown in Figure 1. Real time data is displayed and archived at 

http://www.icess.ucsb.edu/iog/realtime/index.php. 
Final Technical Summary – Washburn 

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Figure 1. Study area in the Santa Barbara Channel. Black arrows show surface current vectors scaled according to 

the scale in the upper right-hand corner. Observations are a 25-hr average centerd on 0900 GMT on 13 June 2006. 

Vectors are spatial averages over circles with radii of 3 km as shown by the circle to the right. HF radar sites are 

shown with yellow triangles. Oil platforms are squares. 

An important new site installed toward the end of this project is at the Summerland Sanitary 

District plant in Summerland, CA. The site at the Mandalay Generating Station (Mandalay in 

Figure 1) was also installed during the project, but has not consistently obtained data due to 

electrical power problems at the site. These power problems have recently been corrected by 

Reliant Energy, the owner of the site. In April 2006 a new and dedicated circuit was installed to 

power our equipment. Radar hardware was obtained through grants from the W.M. Keck 

Foundation and the University of California Marine Council. Two systems were borrowed from 

NOAA’s Environment Technology laboratory in Boulder, Colorado, and a third from Stanford 

University. Operational support for the radar array has come from a number of agencies 

including: Minerals Management Service, Partnership for Interdisciplinary Studies of Coastal 

Oceans (PISCO), University of California Marine Council, and NASA. 

Throughout most of this study, each radar system produced time series of radial current 

components (hereafter referred to as “radials”) out to a maximum range of 40-80 km off shore 

depending on environmental conditions and software version. As discussed by (Emery et al., 

2004), the actual range and overall coverage area changes in time. For the 12-13 MHz systems 

used in this study, radials are obtained as spatial averages over sectors of the sea surface 

measuring 5 degrees in azimuth by 1.5 km in range. Radials in each sector are computed over 10 

minute intervals. Total current velocity vectors are estimated by averaging all radials each hour 

over circular areas of the sea surface with 3 km radii. The circles are centered on points on a 

square grid with two km spacing between points. The least square technique described by 

(Gurgel, 1994) is used to combine radials within the circular areas to estimate the eastward and 

northward current components at each grid point. 
Do Platforms Off California Reduce Bocaccio Recruitment 

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OBJECTIVES: 

The original objectives of this project were not fully achieved during the project period because 

of difficulties encountered in gaining access to suitable HF radar sites in the eastern Santa 

Barbara Channel. MMS was kept informed of this situation during the project through routine 

quarterly reporting of progress on the project. 

Toward the end of the project, sites were obtained near Summerland, California. A private home 

owner allowed the short-term installation of a site on his property from 1 May – 1 September 

2004. This site supported a MMS-sponsored experiment to examine oceanographic factors 

leading to settlement of fish larvae on two oil production platforms. This project is an on-going 

collaboration with the research group of Dr. Milton Love of the Marine Science Institute at 

UCSB. Later, the Summerland Sanitary District allowed installation of a site on a more 

permanent basis nearby (about 1 km east); that site began operation in April 2005. Below we 

describe results of observations obtained with the other radars which addressed important new 

aspects of the circulation in the Santa Barbara Channel (SBC). Results also address a new 

method to assess the performance of HF radars for measuring ocean surface currents. 

DESCRIPTION: 

Evaluation of HF radar performance using Lagrangian drifters 

In collaboration with Dr. Carter Ohlmann and his research group, comparisons were made 

between velocity estimates obtained by HF radar and those obtained by arrays of drifters in the 

SBC. These experiments were moved from the originally-proposed location in the eastern SBC 

to the central channel when we were unable to secure eastern HF radar sites. Previous 

comparison (e.g. (Shay et al., 1998; Emery et al., 2004)) focused on comparisons with moored 

current meters. Because current meters are effectively point measurements in the ocean, they 

are fundamentally different from current measurements obtained by HF radar. This is due to the 

fact that radar measurements are inherently averaged in space and time. The hypothesis driving 

this analysis was that the velocity differences observed between current meters and HF radars 

result from the different ways the two methods observe the ocean, point measurements versus 

spatial averages. If spatial averaging is accounted using drifters spread over areas comparable to 

those over which the radars measure velocity, then differences should be reduced. An 

experiment was conducted to test this hypothesis. 

As part of the test, dense arrays of surface drifters were used to quantify the flow field on time 

and space scales over which the HF radar observations are measured. Up to 13 drifters were 

repetitively deployed off Coal Oil Point (COP) in the SBC on 5 days during an 18 month period. 

The deployments were within coverage of the radars at COP and Refugio (RFG). During each 

deployment day, a group of drifters was released on a regularly spaced grid within a 2 km x 2 km 

square. To reduce geometric pointing errors, the deployment square was located such that radial 

vectors to the COP and RFG radars were nearly perpendicular. As drifters moved from the 

square they were retrieved and replaced to maintain a broad spatial distribution of observations 

within the sampling area during the day. This sampling scheme resulted in up to 56 velocity 

observations distributed over the time (1 hr) and space (1 to 4 km-2) scales from which surface 
Final Technical Summary – Washburn 

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current maps from HF radar are computed. As shown in Figure 2, root-mean-square (rms) 

differences between HF radar radial velocities and average drifter velocities are mostly 3 to 5 cm 

s

-1, much less than the 9-20 cm s-1 typically reported in the literature (e.g. (Shay et al., 1998; 

Emery et al., 2004)). The reduction over past validation studies employing current meters is due 

to improved resolution by the drifters of small scale velocity structures that are included in the 

time- and space-averaged HF radar measurements. Roughly 5 cm s-1 of the differences can be 

attributed to sampling on the differing time and space scales observed by drifters and current 

meters. 

Figure 2. RMS difference between radar and drifter total velocity components for area of Coal Oil Point near Santa 

Barbara, CA versus number of drifter observations used to compute the drifter mean. HF radar totals are hourly 

averages within a 2 km square. Drifter velocities are corresponding time and space averages with randomly subsampled sets within the square. The u component (*) is east-west and mostly along-shore in the study region. The v 

component (o) is north-south and mostly across-shore. Error bars show standard error. 

Despite generally good agreement, differences can increase strongly with time. In one instance 

from a HF radar array in San Diego, the difference increased from near zero to more than 20 cm 

s

-1 within 2 hr. The rms difference and bias (mean absolute radial speed difference) for that day 

exceeded 7 and 12 cm s-1, respectively. Overall, however, these observations show that HF 

radars measure surface currents more accurately than has been inferred based comparisons with 

current meters. Results of this work are summarized by Ohlmann et al.(submitted to the J. 

Oceanic and Oceanographic Technology). Results were also presented at the 2006 Ocean 

Sciences meeting in Honolulu. 

Currently, Ohlmann’s and Washburn’s research groups are examining the capability of the HF 

radars for predicting current trajectories. The observational approach is to deploy drifters within 

the observational field of the HF radars over time periods of up to a few days (i.e. before the 

drifters exit the SBC). As shown in Figure 3, separation distances between actual drifters and 

pseudo-drifters derived from HF radar observations increase through time. Separation rates are 

about 0.2 km hr-1 in the along shore (x) direction and 0.3-0.4 km hr-1 in the cross-shore (y) 
Do Platforms Off California Reduce Bocaccio Recruitment 

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direction. Data of Figure 3 were obtained from the COP and RFG radars for a location in the 

central SBC over a time scale of just over 4 hr. Data from other experiments are being examined 

to evaluate trajectory predictions on scales of about 1 day. A principal goal of this research is to 

quantify trajectory differences for use in models combining HF radar observations with 

stochastic models representing unresolved small scale velocity structure. A collaborator on this 

project, Dr. Arthur Mariano of the Rosentiel School of Marine Sciences at the University of 

Miami, is an expert on these modeling approaches. 

Figure 3. Separation distance between actual drifters and “pseudo-drifters” computed from HF radar time series as 

a function of time. At time t = 0 the separation distance was zero. The x-separation distance (*) is east-west and 

mostly along-shore in the study region. The y-separation distance (o) is north-south and mostly across-shore. Error 

bars show standard error. 

Small coastal eddies in the Santa Barbara Channel 

During this project, small coastal eddies were discovered along the mainland coast of the Santa 

Barbara Channel using observations from the HF network described above. The eddies 

frequently occur along the mainland coast of the SBC between Santa Barbara and Pt. 

Conception. They are 4-15 km in diameter and typically last about 2 days, although some last up 

to 6 days. Most eddies within the radar coverage area are clockwise with rapid rotation rates; the 

rates typically equal to about half the earth’s rotation rate at the latitude of the SBC. Moored 

observations over the inner shelf (12 - 15 m water depths) showed that these eddies can 

occasionally move previously upwelled nutrients on shore. We speculate that these eddies are an 

important transport mechanism for nutrients and biogenic particles to inner shelf regions and 

nearshore kelp forests. They would also advect oil and other pollutants toward shore. Figure 4 

shows an example a small anti-cyclonic eddy on 30 August 2002 lying offshore, just west of 

Refugio. This eddy was centered over the 100 m isobath with strong clockwise rotation (blue 

area). The counter-clockwise pattern southeast of this eddy (red area), only partly resolved by 

the radar coverage in this figure, is a persistent feature of the SBC circulation (Harms and 

Winant, 1998; Nishimoto and Washburn 2002; Beckenbach and Washburn, 2004; Dever, 2004). 

The more frequent occurrence of clockwise eddies suggests that interaction with the bottom is 

partly responsible for their formation. Further discussion of these eddies is given by (Bassin et 
Final Technical Summary – Washburn 

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al., 2005). This work was also the focus of the Masters Thesis of Ms. Corinne J. Bassin, a 

graduate student in the UCSB Interdepartmental Program in Marine Science. 

Figure 4. Surface velocity field on 30 August 2002 at 0000 GMT showing small anti-cyclonic eddies (clockwise 

arrows) south of Coal Oil Point (COP) and southwest of Refugio (RFG). Color contours show rotation rate (i.e. 

relative vorticity) normalized by the earth’s rotation rate f. Red regions show strong counter-clockwise rotation and 

blue areas show strong clockwise rotation. Yellow-filled black squares are HF radar sites at Point Conception 

(PTC), RFG, and COP. Arrows show velocities based on scale to right. Red arrows are velocities measured at 

nearshore moorings and black arrows are velocities measured from HF radar. 

Delivery of larval bocaccio to oil production platforms in the eastern Santa Barbara 

Channel: 

Another important research activity during the project period has been a collaboration with the 

research group of Dr. Milton Love of the Marine Science Institute at UCSB. This MMS-funded 

study is aimed at 1) exploring links between ocean current patterns and the timing of delivery of 

juvenile rockfishes settling on offshore platforms in the eastern Santa Barbara Channel; and 2) 

estimating the proportion of these juvenile fishes that, if the platforms did not exist, would have 

been transported to natural reef habitat. Surface currents in the eastern Santa Barbara Channel 

were mapped using radar for the first time during this study, and the data are being used to 

pursue both research objectives. 
Do Platforms Off California Reduce Bocaccio Recruitment 

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Figure 5. Time series of (upper panel) the number of the number of recently settled juvenile bocaccio and (b) the 

subsurface salinity structure at 26 m depth at platform Gail. 

The field observations of this combined biological and oceanographic study were conducted at 

two platforms, Gail and Gilda, in the eastern Santa Barbara Channel from May through August 

2004. This period corresponded with the season of much of the rockfish recruitment in this area. 

These two platforms, Gail (in about 230 m depth) and Gilda (about 65 m depth) are in a dynamic 

area where ocean currents are variable over a scale of several days and where fronts and eddies 

are observed. Fish settlement was quantified every 3-4 days using SCUBA surveys. Ocean 

surface currents were measured by the HF radar array of Figure 1 while other oceanographic 

monitoring was conducted at the platforms. This monitoring included moored acoustic Doppler 

current profilers (ADCP’s) and temperature-salinity (T-S) recording at both platforms. 

Measurements at platform Gail were made near 30 m depth (yellow line, Figure 5). Vertical 

profiles of water properties were paired with every SCUBA survey. 
Final Technical Summary – Washburn 

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Figure 6. Sequence of daily-averaged surface current maps with hand-rendered flow features (curved orange 

arrows) and abundance of juvenile bocaccio at Platforms Gail and Gilda (gray squares circled in red) during two 

consecutive fish surveys on 28 June and 1 July, 2004. A recruitment pulse of juvenile bocaccio at the two platforms 

is associated with the northwestward flow of surface waters from the Southern California Bight through the eastern 

entrance of the Santa Barbara Channel. 

An analysis of the seasonality of recruitment based on the in situ physical oceanographic data 

has been completed. Multiple lines of oceanographic evidence clearly show that the onset of the 

Gai

Gild

July 1 (Day 183) 

(Fish survey: 200 juvenile 

bocaccio observed at Gilda, 

110 juvenile bocaccio at Gail. 

June 29 (Day 181) 

(No fish surveys on 

days 181 and 182) 

June 28 (Day 180) 

(Fish survey: No juvenile 

bocaccio sighted)
Do Platforms Off California Reduce Bocaccio Recruitment 

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recruitment season of bocaccio rockfish (Sebastes paucispinis) in the eastern Santa Barbara 

Channel was abrupt and coincided with a change of water masses in June 2004. Bocaccio, 

presently declared over-fished by the National Marine Fisheries Service, was the most abundant 

juvenile rockfish observed in this study. Figure 5 shows that a mid-water tongue of low salinity 

water (highlighted in green) broadened and was centered around the depth where the juvenile 

bocaccio settled on Platform Gail during the recruitment season. The same water mass 

phenomenon associated with bocaccio recruitment at Platform Gilda was also evident (data not 

shown). The temperature-salinity properties observed at the platforms near the depth where the 

juvenile bocaccio settled were compared with reference samples of water mass sources in the 

Southern California Current region collected in June 2004 by the California Cooperative 

Fisheries Investigations (CalCOFI). This comparison showed that waters bringing the larval 

bocaccio originated east and south of the channel in the Southern California Bight. 

Figure 6 shows HF radar current patterns before and during the bocaccio recruitment event to the 

platforms around day 183 of Figure 5. The significant finding is that the currents delivering 

juvenile bocaccio recruits to the eastern Santa Barbara Channel platforms were from the 

Southern California Bight and not from within the channel or north of Point Conception. 

Presently, we are working toward objectively analyzing the radar data to explain how the spatial 

and temporal patterns of fish recruitment in the Santa Barbara Channel is linked to current 

patterns. We will be using the radar data to estimate where recruiting fish would be transported 

if the platforms were not present by simulating drifter trajectories from the radar data—these 

results likely will be referenced for platform decommissioning considerations. Preliminary 

results were presented by Mary Nishimoto at the Ocean Science Meeting in Honolulu, HI in 

February 2006. 

SIGNIFICANT CONCLUSIONS: 

1. Validation of HF radar current measurements is significantly improved if comparisons are 

made with observations on similar time and space scales as used by the radars. Velocity 

differences between the HF radars and arrays of drifters are 0.03-0.05 m s-1, less than half the 

typical differences obtained in comparisons with point measurements such as current meters. 

2. Surface trajectories can be predicted by HF radars, but predictions depart from actual 

trajectories measured by drifting buoys. Based on comparisons with surface drifters, differences 

between predicted and measured trajectories near the coast separate at 0.2-0.4 km hr-1. 

Separation increased more rapidly in the cross-shore direction compared with the along-shore 

direction. Improvements in trajectory prediction may result if models of unresolved scales of 

motion are incorporated. 

3. Small eddies often occur near the mainland coast of the Santa Barbara Channel. The eddies 

are 4-15 km in diameter and typically last about 2 days, although some last up to 6 days. Most 

eddies within the radar coverage area rotate clockwise. It is likely that the clockwise rotation 

results from bottom friction near shore. 
Final Technical Summary – Washburn 

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4. The nearshore eddies are a new transport mechanism for moving nutrients and biogenic 

particles to inner shelf ecosystems of the Southern California Bight. It is likely that they can 

rapidly move buoyant pollutants such as oil and stormwater runoff toward shore. 

5. Larval bocaccio, an important rockfish species in California waters, can recruit strongly to oil 

production platforms. Rapid onset of delivery of the larvae onto two platforms in the eastern 

Santa Barbara Channel (Gail and Gilda) coincided with the arrival of low salinity waters from 

the Southern California Bight. This suggests that monitoring water masses may be useful in 

predicting delivery of rockfish larvae. 

STUDY PRODUCTS: 

Publications: 

Bassin, C.J., L. Washburn, M.A. Brzezinski, and E.E. McPhee-Shaw. 2005. Sub-mesoscale 

coastal eddies observed by high frequency radar: A new mechanism for delivering nutrients 

to kelp forests in the Southern California Bight, Geophysical Research Letters, 32, 

doi:10.1029/2005GL023017 

Beckenbach, E.H., and L. Washburn. 2004. Low frequency waves in the Santa Barbara Channel 

observed by high frequency radar, Journal of Geophysical Research, 109, 

doi:10.1029/2003JC001999,2004 

Cudaback, C., L. Washburn, and E.P. Dever. 2005. Sub-tidal inner-shelf circulation near Pt. 

Conception, California, Journal of Geophysical Research and Oceans, 110, C10007, 

doi:10.1029/2004JC002608 

Emery, B.M., L. Washburn, and J.A. Harlan. 2004. Evaluating radial current measurements 

from CODAR High Frequency radars with moored current meters, Journal of Atmospheric 

and Oceanic Technology 21(8): 1259-1271. 

Emery, B.M., L. Washburn, M. Love, M.M. Nishimoto, and J. C. Ohlmann. 2006. Do oil and 

gas platforms off California reduce recruitment of bocaccio (Sebastes paucispinis) to natural 

habitat? An analysis based on trajectories derived from high frequency radar. Fisheries 

Bulletin, 104: 391-400. 

Ohlmann, C., P. White, L. Washburn, E. Terrill, B.M. Emery, and M. Otero. 2006. 

Interpretation of coastal HF radar derived surface currents with high resolution drifter data, 

Submitted; Journal of Atmospheric and Oceanic Technology. 

Research Presentations:

Anderson, C.R., M.A. Brzezinski, D.A. Siegel, L. Washburn, and N. Guillocheau. 2004. Are 

harmful algal blooms responsible for the variability in phytoplankton species composition 

during spring blooms in the Santa Barbara Channel? ASLO/TOS Ocean Science Research 

Conference, Honolulu, HI, 15-20 February.Bassin, C.J., L. Washburn, and E. McPhee-Shaw. 

2003. Sub-mesoscale eddies along the northern Santa Barbara Channel: A possible 
Do Platforms Off California Reduce Bocaccio Recruitment 

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mechanism for nutrient delivery to the inner shelf”, Eastern Pacific Ocean Conference, 

Wrigley Marine Science Center, Catalina Island, CA, 24-27 Sept. 

Bassin, C.J., L. Washburn, E.E., and McPhee-Shaw. 2004. Sub-mesoscale eddies along the 

northern Santa Barbara Channel: A possible transport mechanism for particle transport across 

the inner shelf. ASLO/TOS Ocean Science Research Conference, Honolulu, HI, 15-20 

February. 

Beckenbach, E.H. and L. Washburn. 2003. Vorticity, divergence, and flow states in the western 

Santa Barbara Channel. Eastern Pacific Ocean Conference, Wrigley Marine Science Center, 

Catalina Island, CA, 24-27 Sept. 

Emery, B.M., M.M. Nishimoto, L. Washburn, and M. Love. 2003. Alternative fate estimation of 

oil rig bocaccio recruits using HF radar. Eastern Pacific Ocean Conference, Wrigley Marine 

Science Center, Catalina Island, CA, 24-27 Sept. 

Emery, B., M. Nishimoto, L. Washburn, and M. Love. 2004. Do offshore platforms affect the 

fate of recruitment boccacio? An analysis based on HF radar derived surface trajectories. 

Poster presented at the Thirteenth Western Groundfish Conference, Victoria, British 

Columbia, Canada, 9-13 February. 

Emery, B., M. Nishimoto, L. Washburn, and M. Love. 2004. Do offshore platforms affect the 

fate of recruitment boccacio? An analysis based on HF radar derived surface trajectories. 

Fourth International Radiowave Oceanography Workshop, Townesville, Australia, 21-23 

April. 

McPhee-Shaw, E., L. Washburn, and D. Siegel. 2003. Low-frequency dynamics and nutrient flux 

to the inner shelf of the Santa Barbara Channel. Eastern Pacific Ocean Conference, Wrigley 

Marine Science Center, Catalina Island, CA, 24-27 Sept. 

McPhee-Shaw, E.E., D.A. Siegel, L. Washburn, D. Reed, and M. Brzezinski. 2004. Spring 

Upwelling in the Southern California Bight - Three Seasons of Observation. AGU Ocean 

Science Meeting, Portland, OR, 26-30 January. 

Nishimoto, M. M., L. Washburn, M. Love, D. Schroeder, and B. Emery. 2005. Is the delivery of 

juvenile fishes settling on offshore platforms linked to transport by ocean currents? 

American Fisheries Society Annual Meeting, Anchorage, AK; September 11-15, 2005. 

Nishimoto, M. M., L. Washburn, M. Love, D. Schroeder, and B. Emery. 2005. Is the delivery of 

juvenile fishes settling on offshore platforms linked to transport by ocean currents? 8th 

International Conference on Artificial Reefs and Related Aquatic Habitats (CARAH). April 

10-14. Biloxi, MS 

Nishimoto, M M, L. Washburn, M. Love, B. Emery, and D. Schroeder. 2006. Is the Timing of 

Juvenile Reef Fish Settlement Linked to Local and Regional Ocean Current Patterns? 

AGU/ASLO Ocean Sciences Meeting, 20-24 February, Honolulu, HI. 
Final Technical Summary – Washburn 

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Ohlmann, C., P. White, L. Washburn, E. Terrill. 2006. Interpretation of HF Radar Derived 

Surface Currents with Arrays of GPS-Located, Reusable Drifters. AGU/ASLO Ocean 

Sciences Meeting, 20-24 February, Honolulu, HI. 

Palomino, E., M. McManus, J.L. Largier, L. Washburn, S. Morgan, K. Stolzenbach, B. Sanders, 

M. Stacey. 2003. Adding Value to NEOCO, the Network for Environmental Observations of 

the Coastal Ocean. Eastern Pacific Ocean Conference, Wrigley Marine Science Center, 

Catalina Island, CA, 24-27 Sept. 

Washburn, L. and M. Lavin. 2003. Inverse estuarine circulation in the northern Gulf of 

California. UC-MEXUS Workshop, Ensenada, Baja California, Mexico; 28 November. 

Washburn, L., E.H. Beckenbach, B.M. Emery, C.J. Bassin, C.N. Cudaback, and J.C. Ohlmann. 

2004. Recent results from an array of HF radars on the South-central California Coast. Fourth 

International Radiowave Oceanography Workshop, 21-23 April, Townesville, Australia, 21-

23 April. 

Washburn, L., C. Blanchette, C.N. Cudaback, B.M. Emery, and C. Gotschalk. 2004. Poleward 

flow events around Pt. Conception, California: An analysis based on HF radar and moored 

time series. Fall AGU Meeting, San Francisco, CA, 13-17 December. 

Washburn, L., J.C. Ohlmann, M.M. Nishimoto, C.A. Blanchette, B. M. Emery. 2005. Some 

applications of current-measuring, high frequency radars on the South-Central California 

Coast. 5th Radiowave Oceanography Workshop, Costanoa Conference Center, Pescadero, 

California, 3-6 May.