+--------------------------------------------------------------------------+ | OCEANUS CRUISE SYNOPSIS | +--------------------------------------------------------------------------+ Voyage - Leg: OC 415-2 Voyage Dates: 18 Jul - 04 Aug 2005 Chief Sci(s): Jim Ledwell (McGillicuddy) Address: WHOI Bigelow 103 MS# 12 Phone: 508-289-3305 Email: jledwell@whoi.edu Cruise Objective: Science Activities: TRACER 1 - Tracer Injection and initial sampling for EDDIES project. CTD casts, injection tows, sampling tows, float deployment, glider deployments, drifter deployments, High volume filtering. Operations Area: Sargasso Sea SSSG Tech: Patrick Rowe sssg @oceanus.whoi.edu Departure Port: St. Georges, BERMUDA Agent: Meyer Shipping Somers Wharf 14 Water St. St. Georges, GE BX BERMUDA Contact: Capt. John Moore tel. (441) 297-2303 fax: (441) 292-1583 email: meyershipping@ibl.bm Arrival Port: St. Georges, BERMUDA Agent: Same as above Installed ADCP Scientific XBT System Equipment: Deionized Water CTD/Rosette System - Pressure, 2 C/T pairs 4 conductor slip rings WHOI-Provided UNOLS General Purpose Van Science Tools: Berthing Van ARGOS RDF Program-Provided Sampler Sled - 500 lbs Science Tools: Shipboard GPS Nav Equipment/Nav: Other Night Work Anticipated Requirements: Automatic winch control circuitry Primary CTD winch Secondary CTD winch Wide-mouthed block on starboard boom for secondary wire Wide-mouthed block on A-Frame for secondary wire Crane (2) Air tuggers A-Frame *Note that automatic winch control is crucial for the injection and sampling tows. Notes: Cruise Plan (Rough) Days 1-3 Transit, Site survey with XBT and CTD Days 4-5 Tracer injection Days 6-7 Transition to sampling; ancillary projects over the side Days 8-15 Sampling tows* Days 16-17 Transit back to Bermuda Sampling tows are done overnight and require about 14 hours of wire time. Ancillary projects will be done during the day between tows with the CTD/Rosette over the stern. Details: CTD/Rosette casts will be done from the starboard side prior to the injection, in the normal way. Once injection operations start the CTD/Rosette system will be moved aft to near the stern. During the sampling phase we will shift the wire between the sampling sled and the CTD/rosette once per day to do CTD casts during most days, sampling tows at night. XBT profiles will be done during the first three days of the cruise to locate the center of the feature, where we wish to inject the tracer. ADCP. The ADCP record velocities will be integrated in real time once the tracer is injected to help to keep track of injection. Shears from the ADCP will be used to interpret the observations. The ADCP is therefore crucial to this cruise. Tracer Injection (Ledwell group). The injection sled weighs about 1500 pounds in air and is slightly buoyant in the water. It will be deployed from the starboard side to keep the effect of ship motion on the injection tow as small as possible. Deployment goes as follows: A 200-pound weight at the end of a 50-meter nonconducting cable will be deployed using the secondary winch and wire and an auxiliary wide-mouthed block on the starboard boom. The top of this 50-meter cable is then coupled to the end of the CTD cable and the strain is taken by the CTD winch. A bridle to the injection sled is also coupled to the end of the CTD cable, with the sled sitting on deck. The sled is lifted into the water with the crane, working in unison with the CTD winch and boom, and with the sled controlled by two tag lines. The sled is released from the crane cable as it rides slightly buoyant in the water. It is then lowered to the injection depth (about 80 meters) at about 20 m/minute. Compressible bumpers on the sled collapse as it is lowered to reduce the buoyancy to near neutral. Injection takes about 12 hours at about 1 knot while the winch control system keeps the sled on a previously specified density surface, using feedback from the CTD that is mounted on the sled. The direction of the tow will be chosen to minimize motion at the sled, ideally with both wind and swell off the starboard bow. At the end of the injection tow, the gear is recovered in reverse order, using 2 air tuggers to control it. Tracer sampling (Ledwell group). Sampling tows will be done from the A-frame to give us flexibility in direction of tow. Therefore, the CTD cable and the secondary cable must be led aft to the A-frame after the injection is complete. The lower part of the sampling array is supported by a 50-meter non conducting cable with a 500-pound weight at the bottom. Deployment goes as follows: The weight and cable are deployed over the stern with the secondary winch, wire and sheaves. Ten or eleven 5-liter Niskin bottles, with integrating samplers attached, and two temperature pods are hung on the wire as it is deployed. The top of the secondary cable is coupled to a pendant attached to the sampling sled, which houses a CTD, rosette pylon, and a 50-chamber sampling system. The sampling sled is then lifted with the main CTD cable and lowered into the water. This sled is not neutrally buoyant; it becomes a link between the two cables. As the CTD cable is paid out, ten or eleven more 5-liter Niskin bottles with integrating samplers and two more temperature pods are hung on it. The array is lowered to the same density surface as used for the injection, at about 80 meters depth, and is maintained on that density surface with automatic control of the winch using feedback from the CTD. The array of samplers is tripped by mechanical messenger. The array is towed for ten hours at 1.5 to 2 knots across the suspected location of the tracer patch. The plan is to deploy this system in the evening and recover it in the morning. The CTD cable will be transferred to the CTD/Rosette for day time casts each day, and transferred back each evening. Drogues (Ledwell, Brian Guest). Four ARGOS-tracked drifters, with holey-sock drogues set at the approximate depth of the tracer patch, will be deployed during the injection to help track the tracer. These can be deployed by hand from the stern. Sea Horse Float (Blair Greenan, BIO). The Sea Horse consists of a float with a 200-meter wire and weight suspended from it. An instrument package crawls down the wire, driven by wave action, and then freely rides up the wire while measuring conductivity, temperature, presuure, and velocity. This instrument will be deployed with the crane. The float is 5-feet in diameter and weighs about 1600 pounds. The Sea Horse will be recovered at least once, and most likely will be redeployed near the end of the cruise. A document describing deployment and recovery is available. APEX/EM floats (James Girton and Tom Sanford, U. W.). These are floats that profile to 200 meters while measuring CTD and velocity. They can be deployed by hand. They may be recovered during the cruise. Gliders (Oscar Schofield, Rutgers). Deployment / Recovery of the glider of Oscar Schofield is best done from a small boat, i.e., zodiac Large volume pump samples (Buesseler's student). Four to six battery- operated McLane pumps and filters will be deployed for 4 to 6 hours at a time on a hydro cable. These may be deployed much like the Niskin bottles in the sampling array, i.e., on the secondary wire below the sampling sled. ------------------------------------------------------------------- All hazardous materials will be removed at the end of the last cruise for the EDDIES project, on 15 September 2005, and transferred to my laboratory. Navy Clearance Status: Last Modified: 12/13/2006 Check List: Required? Comments US Customs Form Yes Explosives Clearance No Isotope Use Approval No Diplomatic Clearance Yes Bermuda SCUBA Diving No