I think I can say with all honestly, that I have now experienced
proper Antarctic weather. A few days ago, I told you how a storm was
a-brewin', well today, I think the weather system hit us. Luckily,
being in shallow water and amongst ice, the swell and waves were very
subdued, but the wind, my goodness. Gusts peaked at over 50 knots,
with normal speeds hovering around 40 knots or above. I'm not sure
how strong that is in "normal" wind speed metrics, but let me tell
you it was bloody strong. Coupled with the snow that was falling at
this time, it was basically blizzard conditions, and I obviously was
outside experiencing all of it. The wind was actually so strong that
I couldn't walk forward, and was sliding back on the frozen deck. At
one point, I even had to cower behind a wall and wait for the wind to
subside before dashing for the door. I felt most sorry for the poor
penguins, but saying that, I'm sure they are used to much, much
worse.
Due to the recent snow, strong wind, and negative temperatures, the
entire aurora is essentially covered with a thin layer of ice; from
the deck, to hand rails, to ropes, to equipment, everything! In some
regions, this was probably 1cm thick...it's pretty awesome. I forgot
to mention that yesterday, whilst dashing from the port to the
starboard side of the ship to see penguins, I did actually slip in
the ice and fell right down; luckily I was alone, but I most
certainly laughed to myself. With the recent snowfall, the decks were
also covered with probably 2cm of snow, with much deeper drifts. This
brought out the inner child in those brave enough to venture outside,
and the creation of snowmen, snow angels, and snow-ball fights
ensued. Combined with the slice of Christmas cake I just had, I feel
like I am finally experiencing the Christmas that I missed!
I also got a few hours off today. The plan for tomorrow was to deploy
some moorings, allowing the monitoring of water movement through a
particular region. Unfortunately, a massive iceberg is grounded in
the region where these moorings were to be deployed, which meant much
of today was spent doing bathymetry runs to find a new location.
Fortunately for me, this meant no CTDs for about 4 hours, time I
spent doing absolutely nothing :)
A few of you have actually asked for more details about what I'm
doing...I will try and explain:
The major point of oceanographic cruises is to collect data, and thus
samples, from the ocean. The way they do this is to drop a big
cylindrical frame into the water (attached to a winch of course so it
can be retrieved). Attached to this frame (or rosette) is a CTD, or
Conductivity Temperature Depth profiler, which as the name suggests,
measure conductivity (salinity), temperature, and depth, some very
useful information! Also attached to the rosette are 24 niskin
bottles, used to collect water samples. In the CTD room aboard the
ship is a live feed of the CTD information, so on the way down, the
CTD-team look at the profiles to see where they would like water to
be collected from. On the way back up, with a click of a button, the
niskin bottles are fired, water is collected, and the bottle is
closed. This is done at the 24 depths (we're now actually only doing
12 as the ocean is only ~500m deep, compared to the 4km it was
earlier). The now-full, rosette, is then brought back onboard, ready
for the niskin bottles to be "milked". This basically involves
filling various bottles up with the water from the niskins. Many
different water samples are taken for a variety of subsequent
analyses:
- firstly comes oxygen
- then helium (if being measured)
- then pH (me!)
- then Dissolved inorganic carbon (or total CO2) (me!)
- then alkalinity (me!)
- then salinity (just to check the CTD measurement)
- then nutrients (not exactly sure what nutrients...)
- sometimes delta 18-oxygen is also sampled
- and lastly, the bio guys come along and take some water to check
for critters
After the "milking" is complete, the various teams go off and do
their analyses. Now not all of the above samples are analysed
straight away, ours, however, are (or near enough anyway). My job is
the pH analysis. Taking the cells with the sampled water (after
allowing to come to room temperature), I simply put the cell in a
machine, and click a button. The pH works my using the spectral
signal of the water. After taking the initial spectrum of the "blank"
water, I add some indicator which turns the water purple, and measure
the spectral signature again, record the temperature of the sample
and BAM, job done! This is done for each individual sample, and
following this, some matlab code calculates the actual pH using the
aforementioned spectral signatures. It's pretty simple really, just
very monotonous. Apparently we have been getting some good results,
so go me!
I've probably bored you enough now with that, so I will get back to
you another day about some of the other stuff going on onboard.
Current Latitude: -66.1450
Current Longitude: 142.8790
Current Air Temp: -0.3C (wind chill of -6.4C - when I was outside
during my shift, air temp was -3.0C, with wind chill of -13.8C!!!!!)
Current Ocean Temp:-0.88C
Wildlife: Adelie Penguins
Sea sickness: none
___________________________________________________________________________
Australian Antarctic Division - Commonwealth of Australia
IMPORTANT: This transmission is intended for the addressee only. If you are not the
intended recipient, you are notified that use or dissemination of this communication is
strictly prohibited by Commonwealth law. If you have received this transmission in error,
please notify the sender immediately by e-mail or by telephoning +61 3 6232 3209 and
DELETE the message.
Visit our web site at http://www.antarctica.gov.au/
___________________________________________________________________________
