Dana Tomlinson: Day 6, March 6, 2002

NOAA Teacher at Sea

Dana Tomlinson

Aboard NOAA Ship Ka’imimoana

March 1 – 27, 2002

Date: Wednesday, March 6, 2002

Latitude: 11°N
Longitude: 110°W
Seas: 2-5 ft.
Visibility: unrestricted
Weather: cloudy

Today was not as nice as it has been this week, but it still beats winter in Chicago (which I did for several years). And people from Chicago, please don’t write me that I hate Chicago – it’s one of my most favorite places. I have very fond memories of living there. Anyway, the seas have kicked up a bit, the ship is a’rocking and a’rolling and the weather is cloudy and humid. But life goes on here on the working laboratory that is the Ka’mimoana.

The significant event of the day was our first real CTD cast. I’ve written about these for the last few days, but today I want to really explain it because its scientific work is significant to the entire planet. Once again, CTD stands for Conductivity Temperature Depth. These are all things that are tested by this machine, and more. The machine itself is a steel frame that has 14 cylinders that hold from 4 to 5 liters of sea water that is captured at different depths in the ocean. There are numerous steps in the process of collecting the water – it’s not nearly as simple as it sounds.

First, the computers need to be set up. Then the machine itself has to have the bottles set properly to “fire” later. Then the winch operator and the CTD survey tech work together to lower the machine into the ocean down to 1000 meters. Once there, the survey tech “fires” off the first bottle by a computer key stroke – this snaps closed the top and bottom of the cylinder, thereby capturing the water at that depth. The winch hauls the machine up to 800 meters and it happens again. It happens again at 600m, 400m, 200m, 150m, 100m, 60m, 40m, 25m, 10m and surface. Then, the machine is hauled out by the winch operator (assisted by the survey tech in a life vest who is harnessed to the ship so she doesn’t fall overboard) and put back on deck. Before the machine is cast, when it is at depth and when it is at the surface, numerous statistics are notated such as SST (sea surface temperature) and SSS (sea surface salinity).

At this point, the survey tech shuts down the machines and the computers are done. Then the survey tech goes outside, fills up glass bottles with samples of the sea water from every depth that will be tested in a salinometer later. The machine is hosed down, tied down, and left for the next cast 6 hours later. The information collected from this machine taken over time (and NOAA has been doing these for years now) helps scientists to predict the El Niño and La Niña conditions which can wreak havoc world-wide.

Question of the Day: 

What is a thermoclime? (thanks to Ben Moore, NOAA scientist)

Answer of the Day: 

I guess I’m going to have to make these harder because all sorts of people got this one! Believe it or not, Vanessa P. of San Diego was the first one again to answer it! An anemometer is a device that measures wind speed and direction. Several of them are on board for deployment on the voyage.

Til tomorrow,
🙂 Dana

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