NOAA Teacher at Sea
Debra Brice
Onboard R/V Roger Revelle
November 11-25, 2003
Mission: Ocean Observation
Geographical Area: Chilean Coast
Date: November 17, 2003
Data from the Bridge
1. 171700Z Nov 03
2. Position: LAT: 20-10.8’S, LONG: 085-05.1’W
3. Course: Hove to
4. Speed: 0 Kts
5. Distance: 0 NM
6. Steaming Time: 0H 00M
7. Station Time: 24H 00M
8. Fuel: 1845 GAL
9. Sky: Cldy
10. Wind: 110-T, 18 Kts
11. Sea: 110-T, 2-3 Ft
12. Swell: 140-T, 3-5 Ft
13. Barometer: 1020.0 mb
14. Temperature: Air: 21.5 C, Sea 18.0 C
15. Equipment Status: NORMAL
16. Comments: WHOI buoy recovery in progress.
Science and Technology Log
The R/V REVELLE was positioned roughly 100 meters upwind from the anchor position. The acoustic release was fired and it took approximately 40 minutes for the glass balls to come to the surface. Once the glass balls were sighted the small a line was attached and they were pulled to the stern of the ship. The line was threaded through the A frame, the winch hauled the glass balls over the stern of the boat. Once all the glassfuls were onboard the process of uncoupling them to the mooring began, they were then loaded in groups of 4 into the shipping container to be sent back to WHOI.
Once the fantail was cleared, hauling began. The polypropylene line was then spooled off using a winding cart and 7 empty wooden spools. (see photos) The line on the winch was off loaded into a wired basket which was then wound onto the wooden spools and then stored. This process was repeated for several hours until all of the 2800 meters of line was recovered and the first instrument was brought aboard about 2pm. Then we began to bring each instrument aboard and label it by depth and place it on the deck in the order it was recovered for labeling and photographing. It is very important to document the exact condition of the instruments as they are recovered as it will help in the data analysis later. For example if there are some strange readings in the data or the data suddenly stopped at some point during the year looking at the photograph could tell you that this instrument was covered in barnacles or tangled with fishing line that clogged or blocked the sensors. (see photos)
With 38 different sensors on the mooring it was a very long day just recovering all of them. Once most of the sensors were all onboard and labeled they began the recovery of the buoy and the last 12 sensors. The small boat was deployed and a line attached to the buoy. The ship’s knuckle crane was used in this part of the operation and the buoy was lifted and secured onto the port side of the ship (see photos). Once the buoy was secured the retrieval of the last instruments began. Again, labeling and photographically documenting the condition of the instruments was essential. In the photos you can see the increase in bio-fouling as the instruments get closer to the surface. The current meters nearest the surface were heavily clogged with fishing lines and although their temperature sensors were still functioning, the portion that measures the current direction and speed was completely jammed with the fishing line.
Although acoustic current meters are also used on the mooring, there has been some issues with the quality of their data and the mechanical current meters are still the most accurate, but they have the problems of being more susceptible to bio-fouling and interference with fishing gear. This emphasizes the need for redundant instruments for data collection and comparison. Each year the sensors are evaluated and some changes in instrumentation and slight changes in buoy location might be made. For example this year the buoy will be moved a little farther away from last years mooring to hopefully decrease the likelihood of being tangled by fishing lines. After all of the instruments were secured onboard and labeled and photographed, the cleaning began (see photographs). Everyone participated in this phase with scrapers and , finally the power washer. All of the instruments needed to be cleaned and many stored in the main lab for data analysis tomorrow. All day tomorrow Nan, Lara, Jeff, Jason and Dr. Weller will be downloading and loading at the data from the sensors as well as preparing the new equipment for deployment on Wednesday.
Personal Log
An incredibly long day which began with my watch at 4am and ended sometime after 9pm. It was great and I was fascinated by the differences in the instruments as they were recovered from different depths. It was brought home to me yet again the importance of keeping meticulous and very detailed records of each stage of a operation and the condition of the environment and effect on the equipment. Any of these variables have to be considered when analyzing the data and can only be collected immediately upon retrieval or deployment. It is also essential to have a very detailed plan of operation and to work together well as a team. I think we were also out there testing several brands of sunscreen….mine failed and and I have the racoon-eyes to prove it…ahh well, it was a wonderful day and loved it. Tomorrow and preparing for the deployment will be equally interesting. Oh, and one of the benefits of bringing in the buoy was that all the fish who were living under the buoy were now around the ship and the crew and some of the science staff caught some very nice tuna…hmmm dinner is looking promising tomorrow too:)
Cheers
