Southern Ocean. The Aurora has been blanketed in fog/mist from the
moment I woke up, to now, just before I go to sleep. Not the most
inspiring of weather conditions that's for sure, in fact there's
something quite creepy about being shrouded by fog in the middle of
nowhere, with civilisation hundreds of miles from anywhere...It would
make the perfect start to some cheesy horror movie that's for sure.
The work finally started today with the first test CTD, and my
goodness had I forgotten how long the entire process is (note how I
never said boring there). In fairly deep locations (i.e. 3000m or
so), it takes roughly 3 hours for the whole CTD to descend to the
deepest, darkest depths of the Southern Ocean and come back to the
surface. Along its ascent, the Niskins (basically big bottles
suspended to a metal frame, or Rosette) are fired (or closed),
collecting water samples at strategic depths. These Niskins are
subsequently sampled by us (termed milking the Niskin - another hour
or so), and then analysed by the hydrochemists on board (for
salinity, oxygen, dissolved inorganic carbon, pH, total CO2, etc).
The CTD is also fitted with various other sensors which are
constantly collecting measurements of salinity, temperature, depth,
transmittance, and many other things I can't remember. These CTDs
therefore collect a fairly substantial amount of data, providing us
with information on the current state of the ocean. When data from
previous voyages is thrown into the mix, it's possible to determine
whether any changes are occuring over time. That, my friends, is why
I am here. There you have it, a brief (ok, not so brief) discussion
of my purpose for the next 4 weeks or so. I'm sure I will provide
more tit-bits (?) of information as the voyage goes on.
The temperature continues to decrease further, and with the
wind-chill, the first negative temperatures of the voyage were
recorded (-2.4C I believe). The ship itself also feels bloody
freezing, so I have opted for wearing my thermal top indoors! What
has Australia done to me?
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