Thursday, January 15, 2009

oxygen part 3: the sublime and the mundane

So I've discussed all of the amazing things that you can learn from
dissolved oxygen, now I'll tell you what it means to actually be in
charge of it -- probably a little bit of a let down. When the
rosette/CTD arrives on deck, we sample the (-2 to 2 degree celsius)
water into flasks, being extremely careful not to trap air in it. If
we trap air, we have to do it again. We put a few chemicals in it to
stabilize the oxygen immediately, then store the flasks until I run
the "titrator" -- which is a technique to determine the amount of a
chemical in a solution. In this case we're looking for oxygen and we
use the current running through electrodes submerged in the solution
to determine the concentration of a chemical (which contains
oxygen). From the we determine the amount of O2 that was dissolved
as a gas in the solution. Each titration takes ~5 minutes, but
there's some prep work before and after involving a lot of dishwashing.

A few days ago, I calibrated the machine. The calibration of the
instrument involves running standard after blank after standard
through the machine until you get repeatable results. This took
approximately one 12 hour shift.

We sample 4-10 individual "Niskin" bottles (extra credit for the
origin) per CTD cast and we can have up to 4 CTD casts per day, so
there's always a line of samples waiting to be processed. It reminds
me of Newman's answer to Jerry when he asked him why post office
employees "go postal". Newman went into a long rant with the message
being that the mail never stops coming. Analyzing data on a ship is
like that. As soon as you complete one batch of samples, another few
appear. This is going to go on for another two months. I _think_ I
can keep sane for that long.

A research cruise to the Antarctic entails a mixture of beautiful,
otherworldly scenery and the prospect of answering important, unknown
questions while performing some incredible repetitive but precision-
demanding tasks for hours in a row.

I'm done with the titrator for the night and am going to seek some
inspiration outside as soon as I collect some more water. We'll
worry about analyzing it tomorrow.


  1. Is the bottle name a version of the Nansen bottle? Designed in 1910 for use by oceanographer Fridtjof Nansen and further developed by Shale Niskin?

  2. I love the slideshow, and there a lot of great photos of bergs. But this weekend, we all have to watch out for the Pitts berg!