06. Cruise Letter #5

Dong-Ha Min’s cruise letters from P18 CLIVAR/CO2 Repeat Hydrography expedition in the Pacific Ocean (2007/2008)

Letter #5

Sailing Day 4 (12/17/2007)

22 deg 42 min N, 110 deg 00 min W (1700 PST)

Scattered patchy clouds and dark blue ocean color set the tone of the scene. I started to see flying fish. This creature can easily glide 60-70 m gracefully. We observed dozens of dolphins off the southern tip of Baja California today. This is the last chance to take a glimpse of land before we see Easter Island next month… Someone said he could smell Margarita from the beach, but I doubted it. We were so close from the Baja beach this afternoon. I just hope people are not seeing things already. ^^

We have started to occupy our stations along 110W today from the most shallow location (<300 m deep) moving southward to deeper area. Things are moving smoother today after yesterday’s fiasco during our test cast (cast means we deploy our sensor/sampling package in the water). We do the test cast before we arrive at the real station to check all the procedures and we even collect samples to see if we are getting clean and high quality data. We originally planned to do a test cast the day before yesterday but couldn’t do it due to the various mechanical problems as I had reported earlier.

Last night, finally things looked all good and we deployed the package in the water at 2900 m deep location. Everything looked good until the package was coming up to 500 m depth from the bottom. A new winch operator found that the cable wound on the winch drum had some problem so we stopped. We have 7200 m long conductance metal cable wound on the winch drum for our operation. Whenever the cable is spooled out or wound back to the drum, it should be carefully leveled in orderly manner. Otherwise certain part of the cable can be wound loosely on the drum, and it can cause a sudden snag during the cast which then can cause data damage or, even worse, the cable can actually be cut in the middle of the operation. So this is a critical matter for us. We don’t want to lose our primary instrument and sampler package… We spooled out the cable to deep water for 3000m and re-wound it to the winch drum carefully at this time (wasting our precious time). There have been so many unusual mishaps during this trip, so it is not really stunning anymore, but this shouldn’t have happened.

We typically operate the heavy winch with the several thousand pounds package at a speed of 40 m-60 m per minute speed. With 60 m/min speed, say for a 4500 m deep location, it would take 150 minutes for the package to travel down to the bottom and come up to the surface again before counting the stop times for water sampling. We all hone our patience at sea…

When the rosette package came on deck from the test cast, all people jumped in excitement to collect samples… It was like a market place (see picture). Usually, only fraction of this many people collect water samples, but at this time so many people had been anxiously waiting to see … Even with the normal number of water sampling people, we have someone designated to do the ‘traffic control’ among the samplers. We call this person ‘sample cop’. The sample cop carries a clip board with all the information of individual sampling programs with their sample container numbers, sampler’s name, and their social security numbers (not really), written prior to sampling. Everyone reports to sample cop which (big) water sampler they are taking water from with which (small) sampling containers… Sample cop also checks the order of sampling among different programs (to avoid fist fight and as such) which was already agreed upon.

The bosun (who is in charge of deck work on the ship) carved the wood block in shape of moai (stone statue of Easter Island). He hung it near the aft deck where we do the deck work for good luck (see picture). We may need that after all…

Chief scientist and I are still struggling to come up with the modified sampling plan. So many factors to consider to make a sound decision. We hope we can make our decision by tomorrow. With this many days of loss in science program, we have to compromise something which is not welcome to any scientific party. Captain told us that this ship burns ~4000 gallons of fuel per day when we are steaming… (we’ve steaming at 12-13 knots) no wonder why we had to load up that much in the port.

(Note: 1 knot means the ship is moving in 1 nautical mile per hour, which is about 1852 m per hour)

I tell chief scientist that he is eating too much chips… he is telling me I am eating too much cookies… that’s ok, I guess. Both of us are skinny guys. Just had another excellent dinner. I am going to sleep till my watch starts at midnight!

Good night.

Whiskey Tango Echo Charlie out…

Dong-Ha Min

on NOAA ship Ronald H. Brown

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