Hawaii Ocean Time-series (HOT)
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HOT-161: Chief Scientist ReportChief Scientist: F. SANTIAGO-MANDUJANOHOT-161 Chief Scientist's Cruise Report R/V Ka'Imikai-O-Kanaloa July 12-14, 2004 Cruise ID: KOK0411 Departed: July 12, 2004 at 0930 (HST) Returned: July 14, 2004 at 1400 Vessel: R/V Ka'Imikai-O-Kanaloa Operator: University of Hawaii Master of the Vessel: Captain Ross Barnes Chief Scientist: Fernando Santiago-Mandujano STAG Electronics Technician: Steve Poulos STAG Deck Operations: Dave Gravatt 1. SCIENTIFIC OBJECTIVES The objective of this cruise was to maintain a collection of hydrographic and biogeochemical data at the Hawaii Ocean Time-series (HOT) stations. Three stations were to be occupied during the cruise, in the following order: 1) Station 1, referred to as Station Kahe, is located at 21 20.6'N, 158 16.4'W and was to be occupied on July 12 for about 3 hours. 2) Station 2: ALOHA (A Long Term Oligotrophic Habitat Assessment) is defined as a circle with a 6 nautical mile radius centered at 22 45'N, 158W. This is the main HOT Station and was to be occupied for 3 days from July 13 to July 15. 3) Station 6, referred to as Station Kaena, is located off Kaena Point at 21 50.8'N, 158 21.8'W was to be occupied on July 15 for about 2 hours. A single CTD cast was to be conducted at Station 1 to collect continuous profiles of various physical and chemical parameters. Water samples were to be collected at discrete depths for biogeochemical measurements. Upon arrival at Station ALOHA, a 1000 m CTD cast was to be conducted to collect water for K. Bjorkman's experiment, followed by a net tow, and by the subsequent deployment of a free-drifting sediment trap array. After deployment, a full-depth CTD cast was to be conducted, followed by CTD casts at strict 3 hour intervals for at least 36 hours for continuous and discrete data collection, followed by another full-depth CTD cast. One free-drifting array was to be deployed for 12 hours for incubation experiments on July 14. A plankton net was to be deployed near noon and midnight on July 13 and 14 at Station ALOHA. After CTD work at Station ALOHA was accomplished, the ship was to transit to recover the floating sediment trap array. After recovering the sediment traps, the ship was to return to Sta. ALOHA to continue light cast operations, after which the ship was to transit to Station 6. A near-bottom CTD cast (~2500 m) was to be conducted at Station 6 including salinity samples for calibration, after which the ship was to transit back to Snug Harbor. A Profiling Reflectance Radiometer (PRR) was to be deployed for half-hour periods near noon time on July 12, 14 and 15. A package including a Wet Labs AC9, a Chelsea Fast Repetition Rate Fluorometer (FRRf), and a SeaBird Seacat was to be used to profile the upper 200 m at Sta. ALOHA at noon time on July 14 and 15. The following instruments were to collect data throughout the cruise: shipboard ADCP, thermosalinograph, fluorometer, and two anemometers. 2. SCIENCE PERSONNEL BEACH group: Karin Björkman Research Specialist UH Jennifer Brum Graduate Student UH Tara Clemente Research Associate UH Lance Fujieki Computer Specialist UH Marcie Grabowski Graduate Student UH Tom Gregory Research Associate UH Nick Jachowski Volunteer UH Patricia McAndrew Graduate Student UH Yoshimi Rii Graduate Student UH Dan Sadler (Watch Leader) Research Associate UH Melinda Simmons Graduate Student UH PO group: Bryan Deschenes Graduate Student UH Maya Iriondo Research Assistant UH Xavier Murard Research Associate UH Fernando Santiago-Mandujano Chief Scientist (Res. Assoc.) UH Jefrey Snyder (Watch Leader) Electronics Technician UH Others: Benjamin Van Mooy Post-Doc WHOI 3. GENERAL SUMMARY The cruise was cut short to less than 2.5 days because one of the ship's generators failed during transit to ALOHA station. The ship returned to Honolulu after conducting operations at ALOHA for 10 hours. Operations at Kahe station were conducted as planned. One 1000-m CTD cast was conducted at this station. Due to the ship's generator problem, operations at ALOHA were reduced to a minimum. One deep cast (~4740 m), and four shallow casts between 175 and 700-m were conducted at Station ALOHA. Neither the sediment traps nor the primary productivity array were deployed. The plankton net tows were not deployed either. The PRR was deployed at Kahe Station on July 12, and at ALOHA station on July 13. The ADCP ran without interruption throughout the cruise, as well as the thermosalinograph, fluorometer, and the ship's two anemometers. Winds were easterlies at 20 kt, and sea state 4. We arrived back at Snug Harbor on July 14 at 1400. Full off-load took place on July 15. 4. R/V KA'IMIKAI O KANALOA, OFFICERS AND CREW, TECHNICAL SUPPORT The R/V Ka'Imikai O Kanaloa continues to maintain the excellent ship support for our work. The officers and crew were most helpful and accommodating. They showed enthusiasm and concern for our work and were very flexible in receiving changes in our operational schedule. Technical support during this cruise was excellent. STAG personnel were available at any time to assist in our work and made things much easier for us. 5. DAILY REPORT OF ACTIVITIES (HST) July 10, 2004; Loading Day Equipment loaded on this day. CTD wire was re-terminated and CTD system tested. July 12, 2004 The ship departed from Snug harbor at 0930. Delayed 30 min due to harbor traffic. Fire and abandon ship drills conducted at 1030, followed by a short science meeting during which cruise activities were briefly reviewed, and safety issues were addressed. Arrived to Kahe Station at 1250. Late arrival due to problems with the ship's anchor. A weight cast (400 lb) to 1000 m was conducted at 1300, during which J. Snyder inspected the CTD wire. At 1345 the Profiling Reflectance Radiometer (PRR) was deployed. A 1000-m CTD cast was started at 1437 and ended at 1544, after which the ship headed towards Station ALOHA. The ship's port generator failed during transit to ALOHA at 2100. Continued transit to ALOHA at a speed of 4 kt. July 13, 2004 Arrived at Station ALOHA at 0750. After contacting the UH Marine Center, the captain informed us that we had to head back to Honolulu at 1800 for safety reasons. In the mean time we were able to conduct CTD casts. The cast schedule was modified to optimize the CTD and bottle sampling in the time allotted. One 700 dbar CTD cast was conducted at 0750, followed by one near-bottom cast (4740 m) at 0914, one 200 m cast at 1400, one 175 m cast at 1530, and one 200 m cast at 1700. One PRR cast was conducted at 1315. Departed to Snug harbor at 1730. Ship's speed about 4-5 kt. Winds were easterlies at 20 kt and sea state 4. July 14, 2004 Deployed the CTD at 0500 to collect near surface water for Ben Van Mooy's experiments. Arrived at Snug harbor at 1400. Partial off-load of samples by the BEACH group took place. July 15, 2004 Full off-load of the rest of the equipment. Sub component programs: Investigator: Project/Institution: ----------------- -------------------- Bob Bidigare HPLC pigments/UH Mike Landry Zooplankton dynamics/UH John Dore CO2 dynamics/UH Marcie Grabowski Controls on nitrogen fixation/UH Karin Bjorkman/Nick Jachowski Nutrient Enrichment/UH Jennifer Brum Virus concentrate/UH Ancillary programs: Investigator: Project/Institution: ----------------- -------------------- Charles Keeling CO2 dynamics and intercalibration/SIO Mark Abbott/Ricardo Letelier Optical measurements/OSU Paul Quay DI13C and O isotopes/UW Penny Chisholm Prochlorococcus population dynamics/MIT Ancillary research during this cruise: Investigator: Project/Institution: ----------------- -------------------- Benjamin Van Mooy Phosphate uptake by marine microorganisms/ WHOI |