Wednesday, 10 April 2013

Day 26: adventures of an amateur in the Southern Ocean

Hi all

Sorry for the sudden slow down in posts - A combination of impossible
internet and post-polar-bear-apathy. We are cruising up the A25 line and
are getting back into the blogging now with...a twist! Here is a great
post from our on-board doctor, John. He's spent the last year or so in
South Georgia and below he gives us his perspective on this whole
oceanography caper.

Until tomorrow


Day 26: adventures of an amateur in the Southern Ocean

Three days have passed since the last blog post and there have been
disturbing reports in the news of high spirits and general unrest. As a
medical man, my diagnosis is of mass hysteria secondary to blog
withdrawal and associated anxiety.

Fear not. Despite extravagant reports and the usual partisan analysis of
journalists from London, Paris, New York and Pyongyang, there is nothing
to worry about. We're doing fine but have been so busy pushing back the
Frontiers of Science that we simply haven't had time to write. Indeed,
such are the demands of the work that Jan has had to retire to the bar
for a digestif after yet another 5-course dinner and so it falls to me,
the ship's doctor, to leave my customary spot (which Jan has just taken)
and give you an update on our progress.

When we left you last, we had just finished retrieving and re-deploying
a group of moorings, a noble struggle, as it turned out, between man and
ice, whale and camera. Since then we have returned to what seems to be
the bread-and-butter of oceanography, CTDs. Ah yes! CTDs - I know them
well! Well, as a matter of fact, now I do because whilst they are very
clever bits of kit – collecting water at specified depths in the ocean
and sensing all sorts of things as they go – the final step is to decant
the water out of them into sample bottles for analysis of whatever
happens to float you boat. And this is something that even a doctor can
manage as long as he's moderately sober.

The process is, as I say, relatively simple but perhaps it is worth
telling you a little bit about it to give an idea of the practical side
of the science work. The CTD is a large round structure, sometimes
called a rosette, on which 24 plastic bottles sit. These have stoppers,
top and bottom, which are held open by wires that latch onto hooks in
the middle of the CTD itself. The whole caboodle is chucked into the
sea, sorry, lowered carefully over the side of the ship on a large,
purpose-built gantry.

It is then lowered to whatever depth the scientists want to collect
water from. Using a computer programme, they can then trigger the
latches to release the wires holding the stoppers open. These close and
seal the water from that depth in the bottle. Each one of the 24 bottles
can be triggered independently and so water can be collected at
different levels in the water column. Then the whole caboodle is janked
back out of the drink, sorry, carefully recovered back on board the vessel.

This is where they let monkeys like me help. The CTD comes to rest in
the so-called 'water bottle annex' which, until I knew better, I thought
was where we went for a refreshing libation between vigorous games of
qouits and petanque. It isn't large but can accommodate a CTD and a
smattering of scientists and their simian assistants. It has the virtue
of a roller door – the kind of thing you see on the better class of
boozer – that comes in handy when the weather is rough.

It also has a radio that plays almost constantly a programme of static
interspersed with the songs you didn't want to hear. This keeps spirits
high as we get about our work. Water from each of the 24 bottles on the
rosette is transferred into sample bottles. This, the dark art of clear
water, is more complicated than it sounds. Great care must be taken to
ensure that there are no bubbles in the water as it flows into the
sample bottles. This is because the tracer that we (okay, they…) are
looking for normally exists as a gas at atmospheric pressure. It yearns
to break free from its watery prison and give it the slightest
opportunity – a friendly air bubble or tubulence at the surface of the
water as it collects in the sample bottle – and it will make a break for
it, never to be seen again. Or at least not to be seen in the sample
water that they analyse.

This analysis is done by a very clever machine. I was allowed into the
container in which it lives on the back deck. They only made that
mistake once because although I managed to leave it unscathed (neither
of us were hurt), I could not hide my clumsiness for long and even I had
to accept that my curiosity did not justify wasting years of their work.
I did manage to get some pictures of The Thing that goes beep, and all
sorts of other noises, and requires a regular diet of liquid nitrogen.
Feed Me Seymore! The Little Shop of Horrors doesn't even come close.
Yes, as you can see, I haven't the foggiest how it works and will have
to leave that to the experts to explain.

These scientists are not experts only in the art of blob chasing but are
talented artists as well. In particular the night shift, when not doing
battle with Scientific Frontiers, have taken to decorating our helmets.
Most of us now have the flag of our country of origin emblazonned in
electrical tape upon our nut cases (a technical term, you understand).
That origin may be where we were born or where we feel our spiritual
origin lies. For many years now, I have felt that I am in fact Ugandan
which is the reason that I sport their flag. It has nothing to do with
the fact that it was the most complicated flag design I could think of.
[Any other suggestions are welcome as some helmets remain to be
decorated and, with 3 weeks left to run, they need new challenges to
keep them awake at night. Answers on a postcard, please.]

Photo 1: A late night CTD comes on deck.

Photo 2: The static noise generator (perhaps it has something to do with
the dubious looking aerial).

Photo 3: John with the flag of his spiritual home carefully crafted by
the red-eye tracer team.

Photo 4: Water for the tracer-machine's insatiable thirst.

Photo 5: Many hands make light Sulfur-Penta-Flouride!

1 comment:

  1. Great post. Sounds like you're all having fun(!?)