Hawaii Ocean Time-series (HOT)
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HOT-62: Chief Scientist ReportChief Scientist: D. HEBELHOT 62 Cruise Report R/V Moana Wave 4-9 April, 1995 Personnel List: --------------- WOCE group: Jefrey Snyder (Watch Leader) Electronics Technician UH JinChun Yuan Research Associate UH Craig Nosse Scientist UH Molly Lucas Graduate Student UH-M. Atkinson JGOFS group: Dale Hebel Chief Scientist (co-PI JGOFS) UH David Pence Research Associate UH Terry Houlihan (Watch Leader) Research Associate UH Louie Tupas Scientist(co-PI JGOFS) UH Dan Sadler Graduate Student UH-T. Li Ancillary projects: Chuck Stump Scientist UW-S. Emerson Karen Selph Graduate Student UH-M. Landry Gretchen Rollwagen Graduate Student UH-M. Landry Bob Miller Graduate Student UH-M. Landry Sue Vink Scientist UH-C.Measures Ricardo Letelier Scientist OSU Mai Lopez Scientist SIO-M. Huntley STAG: Steve Poulos Electronic Technician UH-UMC Luigi Pozzi Deck Technician UH-UMC Itinerary (approximate local time): ---------------------------------- Tuesday, 4 April 0900 Departed Snug Harbor 1150 Arrived Kahe Pt. (Sta. 1-1) 1445 Departed Kahe 1830 Arrived Kaena Pt. (Sta 1-2) 2045 Departed Kaena Pt. Wednesday, 5 April 0300 Arrived Aloha (Sta. 2) trap deployment site 0500 Completed sediment trap deployment 0600 Arrived Aloha (center of circle), WOCE deep cast 1100 Began 36 hr burst sampling 1230 Plankton net tow Thursday, 6 April 0100 Plankton net tow 0330 Commenced Go-Flo cast 0545 Deployed primary productivity array 1300 Plankton net tow, PNF, TSRB 1900 Retrieved primary productivity array 2000 Pumped tanks 2100 Discovered compromised nutrient samples 2200 Plankton net tow Friday, 7 April 0030 Completed "burst" sampling 0100 Plankton net tow 0400 Began ancillary work and repeated JGOFS and WOCE nutrient collections 1500 Began Optical Mooring Buoy deployment 2000 Completed triangulation 2130 Began equipment recovery operations Saturday, 8 April 0600 Completed recovery operation 0900 Began sediment trap recovery 1300 Transit station ALOHA 1630 TSRB 1700 Deployed OPC Sunday, 9 April 0600 Recovered OPC 0730 Arrived Snug Harbor 1000 Offloaded Narrative: --------- HOT 62 was conducted 4-9 April, 1995 aboard the R/V Moana Wave with Capt. Hayes as Master. All over-the-side operations were completed and all samples collected although the nutrient samples collected at Kahe and Kaena are most likely compromised. Ricardo Letelier (OSU) deployed a moored optical buoy (MOB), followed by a dragging attempt to recover our lost equipment. The optical plankton counter (OPC) was deployed on the return leg. We departed Snug Harbor 4 April 1995 at 0900 hrs. We were scheduled to leave at 0800 hrs but were delayed one hour while critical sample documentation and essential chemicals were delivered from UH. Once outside the mile buoy the First Mate (John Stahl) conducted the routine fire and abandon ship drills. A short science meeting followed to delineate the cruise plan, watches, core work and ancillary projects. At Kahe we conducted a weight cast to 500m followed by a PNF and TSRB (tethered spectraradiometer buoy) cast and finally 1000 m CTD cast. All equipment operated properly with the exception of the TSRB. The problem was subsequentially corrected. After all samples were collected we departed Kahe for Kaena Point. Upon arrival at station 6 (Kaena Point) a CTD cast to 2498 db was conducted with 15 bottles tripped for DO, Chla, and LLN samples. Following the Kaena Point station we steamed to station ALOHA. Once on station we deployed the sediment traps and initiated CTD operations. The JGOFS spectraradiometer was slated for deployment on the trap line, however, the correct buoyancy components were not available and therefore the instrument was not deployed. Routine sampling ensued through the 36 hr brust sampling period until it was recognized (~2000 hrs 4 April 95), that the freezer top, where the nutrient samples were stored, had been left open. Upon closer examination it was determined that all samples were thawed and, at this point, it was not clear if they had ever been frozen. Due to time constraints we were unable to resample the Kahe Point and Kaena Point stations, therefore, these samples were not discarded. However, we were able to resample the standard JGOFS and WOCE shallow and deep nutrient samples. Subsequent measurements of the chest freezer temperature indicated that it could not attain a temperature low enough to freeze seawater samples. The day following the incident the temperature was 0.5 C and by the end of the cruise had climbed to 10 C. With the completion of the core and ancillary work at station ALOHA we steamed NNE (~050 T) just outside the ALOHA circle and surveyed the bottom topography for the proper bathymetry and relief for the deployment of the MOB. Having found the correct locale and being careful to avoid phone cables we backtracked the required distance to ascertain the placement of the mooring in the correct location. Following deployment (~2 hrs; 22 50.87 N, 157 55.55 W anchor away location) we fixed the position by triangulation before departing to the lost equipment postion. Although a position was derived (?N, ?W), one of the 3 points was less than ideal resulting in a relatively imprecise, but hopefully, reasonably accurate determination. With the realization that the core nutrient samples would have to be resampled the equipment recovery operation was tentatively scrubbed. However, expedient use of CTD sampling depths and time resulted in the collection of a full sample set within a time frame which still permitted an equipment recovery attempt. It has become a realization that no extra time is available on our HOT cruises. This is especially true with upcoming cruises and therefore the current, yet limited, time frame was viewed as an opportunity to learn and better yet possibily succeed at a most improbable task. One of the two goals was achieved. We did learn that the configured dredging array would remain on the bottom when underway and we did learn that the terminal grapnel hook was effective. We managed to hook something on the bottom that effectively protracted the operation for a period of hours over that initially intended. The substance of the connection was so great that it literally pulled the ship backwards allowing winch speeds of only 0-10 m/min with associate tensions of 10-14K lbs with the main engines decluthed. PDR recordings revealed a varied bottom releif grading from flat to a ridge-like structure where contact was made. This was in a vicinity which was past the most probable point of contact for the lost equipment. After the unsuccessful recovery attempt we steamed to the vicinity of the sediment traps which were located and recovered without incident. Following the recovery we conducted the AC-3 test cast and collected samples for <202 um suspended matter (TSM), outside the circle confines. The data of the AC-3 test cast which profiled to 2000 m have not been processed but the initial response from Jefrey was unfavorable. The deployment of the OPC was scheduled to begin at the trap recovery site and proceed to just outside Honolulu Harbor. However, a request from the scientist in charge (Mai Lopez), altered the plan to return to station ALOHA, transit the diameter of the circle along 158 then change course for Snug Harbor. The OPC was towed between 8-8.5 kts and retrieved south of Barbers Point. We arrived at Snug Harbor 9 April @ 0730 hrs and since we were the next science group to use the ship offloaded only the handcarried equipment, samples and other essential equipment by 1000 hrs. Weather: -------- The weather was mostly overcast with moderate to high winds and low to moderate seas. Below is listed the cruise log bridge descriptions and the various values represent the range for that day. Under wind, sea and swell there will be two designations, the first is the direction (in degrees), the second for wind is in kts, for sea in Beauford force, for swell in feet, and clouds in tenths. Day Date Wind Sea Swell Clouds Tuesday 4 April 045-055, 20-28 045-055, 3-4 000-030, 3-8 3-8 Wednesday 5 April 050-070, 24-28 050-070, 3-4 030-060, 6-8 7-10 Thursday 6 April 050-070, 14-22 050-070, 2-3 060, 4-8 8-10 Friday 7 April 070-115, 15-25 070-115, 3-4 070-090, 5-6 3-10 Saturday 8 April 110-165, 5-20 110-165, 1-3 090-130, 3-6 3-7 Sunday* 9 April 150, 7 150,1 130, 2-3 2-7 *Only two entries Equipment and methods: ---------------------- All standard equipment used on HOT 62 functioned properly. No equipment was lost, however, one primary productivity sample bottle at 125 m (3L1) was lost. The initial deployment of the TSRB was problematic but was subsequentially repaired. One of the tangs on the terminal grapnel was bent out during the dragging operation. This was a piece of STAG equipment. Sub component programs: ----------------------- Investigator: Project: ------------- -------- Telu Yuan-Hui Li (UH) DIC, pH, Alk., pCO2 Bob Bidigare (UH) HPLC pigments Michael Landry (UH) Zooplankton dynamics Ancillary programs: ------------------- Investigator: Project: ------------- -------- Chris Measures Trace metal studies Steve Emerson Oxygen/Argon/Helium measurements Charles Keeling (SIO) CO2 dynamics and inter calibration Paul Quay (UW) DIC and 13C Hans Thierstein (Zurich) Calcareous plankton dynamics George Luther (UD) Iodine speciation Students: --------- Bob Miller Zooplankton sampling training Gretchen Rollwagen Zooplankton sampling training Others: ------- Ricardo Letelier (OSU) Optical oceanography Mark Huntley/Mai Lopez Optical plankton counting |