SEFCAR / OPRC

SEFCAR / OPRC Project

Principal Investigators: Dr. Tom Lee, Dr. Claes Rooth and Dr. Peter Ortner
Participating Institutions: University of Miami / RSMAS / NOAA / AOML/ CIMAS
Funding: NOAA / CIMAS (Contract NA85-WC-H-06134),USGS / SFOSRC (Agreement # RD-93-02)
Project Dates: April 1989 - Dec 1995

Project Background

South East Florida and Caribbean Recruitment (SEFCAR) - Physical Process Studies in Support of SEFCAR Recruitment Research in the Florida Keys. P.I.’s Tom Lee and Claes Rooth; NOAA collaborator: Peter Ortner. This project was a long-term co-operative study between RSMAS and NOAA/AOML and CIMAS for the purpose of investigating the physical processes associated with the transport of fish and lobster larvae in the Florida Keys using observational and modeling techniques. The primary objective was to establish the physical influence of coastal recirculation features on the retention and recruitment of local and remotely spawned fish and lobster larvae. The investigation focused on the downstream movement and evolution of mesoscale frontal eddies from the Dry Tortugas to the upper Keys, which together with local wind driven circulations, provides a recruitment pathway for fish and lobster larvae into the Florida Keys and Florida Bay nursery grounds, and a mechanism for increased retention times and shoreward transport of pelagic plankton. The approach consisted long-term moored measurement of currents and temperature from the upper Keys to the Dry Tortugas over the period April 1989 to Dec. 1995 together with interdisciplinary seasonal shipboard surveys of the coastal waters and offshore Florida Current frontal region to measure water mass structures simultaneously with larval distributions.

OPRC/EDDY (Offshore Petroleum Research Center/Eddy) – This project was a coordinated effort with the ongoing SEFCAR (South East Florida and Caribbean Recruitment) study conducted by RSMAS and AOML through CIMAS. P.I.’s were Tom Lee and Claes Rooth. The goal of this project was to combine the use of long-term in situ current/temperature moorings, surface drifters and shipboard surveys with results from a Ocean Surface Current Radar (OSCR) system and satellite remote sensing to develop an improved understanding of surface transport processes in the Florida Keys coastal waters and offshore Florida Current.

Project Description - SEFCAR

Moored observations of currents and temperature began in April 1989 with deployment of 3 subsurface, taut-wire current meter moorings along the 30 m isobath located offshore of Carysfort Reef, Tennessee Reef and Looe Reef (Fig. 1). Currents and temperature were measured with General Oceanics winged current meters at depths of 7, 17 and 27 m. Mark I and II current meters were used with burst sampling over a 32 second period to reduce surface wave noise. The Looe Reef site in the lower Keys has been maintained continuously through a series of past and present ongoing studies, and there are now over 17 years of data at this site. Further west, at East Sambo reef a mooring was maintained from July 1993 to May 1994. The upper and middle Keys sites at Carysfort and Tennessee Reefs were in operation from April 1989 to April 1991. A western Keys site off Marquesas was active for more than 3.5 years, from April 1991 to November 1994, and the Dry Tortugas site was maintained for one year, from April 1991 to May 1992. Hawk Channel current/temp mooring sites were maintained using Aanderaa current meters off Marathon from Sept. 1999 to Sept. 2001 and shoreward of Looe Reef from April 1999 to present that included salinity as well. There was also an American Shoal site from July 1993 to May 1994. In addition bottom-moored ADCP's were deployed offshore of the Dry Tortugas at the 200 m isobath from April 1991 to May 1992, and at the 150 m isobath off Looe Reef for the periods August to November 1989; April 1990 to April 1991; and July 1993 to November 1994, to measure variations of the Florida Current. Wind records were obtained from the offshore CMAN stations positioned on lighthouses at Fowey Rocks, Molasses Reef, Sombrero Reef, Sands Key and Dry Tortugas, as well as at Florida Bay stations north of Long Key and south of East Cape Sable. The wind time series are of different record lengths due to sensor malfunctions and this can cause discrepancies in the annual mean wind patterns. The most complete records were from the Sombrero and Molasses stations. All time series are either unfiltered or filtered with 3 and 40 hour low pass (HLP) Lancoz filters for initial smoothing and to remove tidal variations, respectively. The data are then subsampled at 1 hour intervals for the 3 HLP records and at 6 hour intervals for the 40 HLP records. Current and wind vectors from the Keys coastal zone are rotated into an along- and across-isobath coordinate system, where v is positive in the downstream direction (eastward in the lower Keys and northeastward in the upper Keys) and u is positive in the offshore direction. Wind records are extrapolated to a standard 10 m height.

Fig. 1 SEFCAR / OPRC mooring locations Apr 1989 - Dec. 1995

Project Description - OPRC/EDDY

Starting in July 1993, an array of subsurface current meter moorings and a bottom mounted ADCP were deployed for one year that spanned the OSCR surface current mapping area in the lower Keys (Fig. 1 above). Moored current observations provide long-term records suitable for describing the statistical behavior of the background flow variability, especially the time scales and movement of coastal recirculation features. Current records also provide a continuous reference context for the satellite-based pattern analyses, as well as point checks for the OSCR observations. Additional atmospheric data and coastal sea level were obtained from C-man and coastal meteorological stations. Shipboard surveys of water mass properties and plankton aggregations in the vicinity of frontal convergence zones were conducted with the University of Miami R/V Columbus Iselin in Sept. 1993 and with the NOAA R/V Oregon II in May 1994 within the OSCR domain. High resolution surface current maps from OSCR and satellite AVHRR surface thermal images were transmitted to the ship to aid location of frontal features and planning of sampling strategy. Surface drifters were deployed during both summer and spring surveys for performance evaluation against the OSCR data and for surface trajectory analysis of oil spills under the influence of local winds and coastal gyres.
Fall 93 Experiment: The fall 93 experiment was remarkable in that an unexpected large band of low-salinity Mississippi River flood water was observed in the Florida Current and coastal waters of the Florida Keys during a multi-disciplinary cruise aboard the University of Miami Research Vessel Columbus Iselin from September 9 to 13, 1993. Physical, biological and chemical properties were surveyed continuously along a saw-toothed cruise track from Miami to Key West on 9 to 10 Sept. Hydrographic measurements revealed a band of low-salinity 32 to 35 psu that extended throughout the observational area from Key West to Miami, a distance of 260 km. The offshore extent of the band varied from about 45 km off Key West to 37 km off Miami. The vertical extent was about 20 m as determined from a CTD section off Looe Coral Reef Sanctuary. Biological and chemical indicators within the band, together with its large volume suggested the recent Mississippi River flood as the source.
Spring 94 Experiment: The spring 94 experiment was also exceptional in that detailed observations of small-scale frontal vortices were made with the combined use of OSCR, surface drifters and shipboard hydrography and bioacoustics. OSCR derived surface current maps were faxed to the NOAA R/V Oregon II during the May 19 - 26 survey of frontal convergences in the Florida Keys for location and enhanced sampling of 10 to 20 km diameter, cyclonic eddies. These previously unobserved small scale vortices form an important link in the shoreward transport and dispersal of plankton and materials concentrated in the Florida Current front. The shipboard hydrographic measurements revealed an area of cold uplifted water trapped against the steep slope topography on the Pourtales Terrace between Key West and Marathon. Surface flow was to the west on the shoreward side of the strong temperature front at this depth and to the east offshore of the front.

Table 1

SEFCAR / OPRC Current Meter and ADCP Mooring Locations and Deployment Dates

Mooring Name	Latitude	Longitude	Deployment Dates	Water Depth	Sampling Interval
Carysfort (C)	25 12.53 N	80 12.25 W	Apr 89 - Apr 91	30 m	20 or 60 minutes
Tennessee (T)	24 44.63 N	80 46.79 W	Apr 89 - Apr 91	30 m	20 or 60 minutes
Looe Key (L)	24 32.37 N	81 24.11 W	Apr 89 - Present	30 m	20 or 60 minutes
Marquesas (M)	24 27.11 N	82 11.41 W	Apr 91 - Nov 94	30 m	20 or 60 minutes
Dry Tortugas (DT)	24 33.71 N	82 54.03 W	Apr 91 - Apr 93	30 m	20 or 60 minutes
American Shoal (AM)	24 32.58 N	81 32.06 W	Jul 93 - Nov 94	13 m	20 or 60 minutes
East Sambo (ES)	24 28.84 N	81 39.67 W	Jul 93 - Nov 94	30 m	20 or 60 minutes
Looe Key ADCP (L-ADCP)	24 28.39 N	81 21.61 W	Aug 89 - Dec 94	215 m	30 minutes
Dry Tortugas ADCP (DT-ADCP)	24 19.92 N	82 54.18 W	Apr 91 - Apr 92	199 m	30 minutes

Table 2.

SEFCAR / OPRC History of Mooring Deployment at Each Measurement Site (April 89 - Dec 95)

ADCP Location - Dply #	Latitude	Longitude	Water Depth	Deployment Date	Recovery Date
ADCP Looe - Dply 1	24 20.43N	81 14.85W	215.	Aug 12, 1989	Nov 10, 1989
ADCP Looe - Dply 2	24 28.39N	81 21.61W	154	May 19, 1990	Apr 17, 1991
ADCP Tort - Dply 1	24 19.92N	82 54.18W	199.	Apr 19, 1991	Apr 26, 1992
ADCP Looe -Dply 3	24 28.94N	81 22.07W	146.	Jul 15, 1993	Oct 28, 1993
ADCP Looe -Dply 4	24 28.94N	81 22.07W	146.	Oct 28, 1993	Dec 15, 1994

ADCP Location - Dply #	Latitude	Longitude	Water Depth	Deployment Date	Recovery Date
Amer.Shoal - Dply1	24 32.58N	81 32.60W	13.	Jul 16, 1993	Nov 10, 1993
AmerShoal - Dply 2	24 32.58N	81 32.60W	13.	Mar 24, 1994	Dec 03, 1994

Carysfort - Dply 1	25 12.53N	80 12.25W	30.	Apr 08, 1989	Aug 22, 1989
Carysfort - Dply 2	25 12.53N	80 12.25W	30.	Aug 22, 1989	Nov 06, 1989
Carysfort - Dply 3	25 12.53N	80 12.25W	30.	Nov 06, 1989	Apr 27, 1990
Carysfort - Dply 4	25 12.53N	80 12.25W	30.	Apr 27, 1990	Sep 29, 1990
Carysfort - Dply 5	25 12.53N	80 12.25W	30.	Sep 29, 1990	mooring broke loose

East.Sambo - Dply 1	24 28.84N	81 39.67W	30.	Jul 16, 1993	Nov 10, 1993
East.Sambo - Dply 2	24 28.84N	81 39.67W	30.	Nov 10, 1993	Mar 24, 1994
EastSambo-Dply 3	24 28.84N	81 39.67W	30.	Mar 24, 1994	Nov 20, 1994

Looe Key - Dply 1	24 32.37N	81 24.11W	30.	Apr 10, 1989	Aug 17, 1989
Looe Key - Dply 2	24 32.37N	81 24.11W	30.	Aug 17, 1989	Nov 10, 1989
Looe Key - Dply 3	24 32.37N	81 24.11W	30.	Nov 10, 1989	Apr 29, 1990
Looe Key - Dply 4	24 32.37N	81 24.11W	30.	Apr 29, 1990	Sep 21, 1990
Looe Key - Dply 5	24 32.37N	81 24.11W	30.	Sep 21, 1990	Apr 17, 1991
Looe Key - Dply 6	24 32.37N	81 24.11W	30.	Apr 17, 1991	Sep 11, 1991
Looe Key - Dply 7	24 32.37N	81 24.11W	30.	Sep 11, 1991	Apr 25, 1992
Looe Key - Dply 8	24 32.37N	81 24.11W	30.	Apr 25, 1992	Sep 23, 1992
Looe Key - Dply 9	24 32.37N	81 24.11W	30.	Sep 23, 1992	May 12, 1993
Looe Key - Dply 10	24 32.37N	81 24.11W	30.	May 12, 1993	Jul 15, 1993
Looe Key - Dply 11	24 32.37N	81 24.11W	30.	Jul 15, 1993	Nov 10, 1993
Looe Key - Dply 12	24 32.37N	81 24.11W	30.	Nov 10, 1993	Mar 25, 1994
Looe Key - Dply 13	24 32.37N	81 24.11W	30.	Mar 25/26 1994	Nov 20, 1994
Looe Key - Dply 14	24 32.37N	81 24.11W	30.	Nov 20, 1994	Jun 10, 1995
Looe Key - Dply 15	24 32.37N	81 24.11W	30.	Jun 10, 1995	Aug 23, 1995

Marquesas - Dply 1	24 27.11N	82 11.41W	30.	Apr 18, 1991	Sep 12, 1991
Marquesas - Dply 2	24 27.11N	82 11.41W	30.	Sep 12, 1991	Apr 26, 1992
Marquesas - Dply 3	24 27.11N	82 11.41W	30.	Apr 26, 1992	Sep 24, 1992
Marquesas - Dply 4	24 27.11N	82 11.41W	30.	Sep 24, 1992	May 13, 1993
Marquesas - Dply 5	24 27.11N	82 11.41W	30.	May 13, 1993	Jul 16, 1993
Marquesas - Dply 6	24 27.11N	82 11.41W	30.	Jul 16, 1993	Nov 19, 1993
Marquesas - Dply 7	24 27.11N	82 11.41W	30.	Nov 19, 1993	Mar 23, 1994
Marquesas - Dply 8	24 27.11N	82 11.41W	30.	Mar 23 1994	Nov 21, 1994

Tennessee - Dply 1	24 44.63N	80 46.79W	30.	Apr 09, 1989	Aug 19, 1989
Tennessee - Dply 2	24 44.63N	80 46.79W	30.	Aug 19, 1989	Nov 09, 1989
Tennessee - Dply 3	24 44.63N	80 46.79W	30.	Nov 08, 1989	Apr 28, 1990
Tennessee - Dply 4	24 44.63N	80 46.79W	30.	Apr 28, 1990	Sep 22, 1990
Tennessee - Dply 5	24 44.63N	80 46.79W	30.	Sep 22, 1990	Apr 16, 1991

Tortugas - Dply 1	24 33.71N	82 54.03W	30.	Apr 18, 1991	Sep 13, 1991
Tortugas - Dply 2	24 33.71N	82 54.03W	30.	Sep 13, 1991	Apr 27, 1992
Tortugas - Dply 3	24 33.71N	82 54.03W	30.	Apr 27, 1992	Sep 25, 1992
Tortugas - Dply 4	24 33.71N	82 54.03W	30.	Sep 25, 1992	May 14, 1993

All current meter moorings have from one to three Niskin Wing Current meters installed on them at standard depths of 7, 17 or 27 meters. Each current meter records current speed, current direction, water temperature and some have conductivity sensors. The deployment dates above do not necessarily coincide with the data availability. Instrument failures during deployments did occur.

The ADCP moorings consisted of one upward looking Acoustic Doppler Current Profiler which recorded currents at different levels from the transducer heads to the surface. Temperature at the depth of the ADCP was also recorded.

Data – SEFCAR and OPRC mooring deployments

South Florida Coastal Oceanographic Database