Antarctic Astronomy Diaries 2003/04

   

   
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Saturday, November 29, 2003

It won't be long

This morning we made a serious effort to prioritise our remaining tasks, and then to set about crossing them off one by one. This is just as well, because we were informed later in the day that we would be leaving a day early, on Monday, which adds a sense of urgency to our tasks. (We'd been planning on Monday or Tuesday, but there's no flight on Tuesday.)

We've decide to leave Icecam, the instrument responsible for last week's adventures in the crypt, to run for another year here. However rather than returning it to the crypt, we will set it up in the AASTINO which is a much more pleasant environment to work in. I therefore spent much of the morning preparing the battery bank and writing lurid cautionary tales for the benefit of the next team in, who will do the actual installation.

I confess that the lithium thionyl chloride batteries that power Icecam terrify me a little. Each of the "D" size cells contains enough electrical energy to run a suburban train for a week (OK, maybe I'm exaggerating a little here), and an assembly of 24 of them lends new meaning to the phrase "shock and awe".

I also reconditioned COBBER, the little infrared instrument that hangs off Icecam and makes an independent measure of cloud cover by noticing when clouds get in the way of the much colder galactic radiation.

For the past few days there's been a Twin Otter here doing a radar survey of the sub-ice terrain. By choosing the right wavelength (looks like about 3 metres, judging by the antennas hanging below the wings) the radar can penetrate the ice and map out what the ground would look like if there were no ice on it. One of the neat things about this is that you can discover subterranean lakes, some of which still contain liquid water. Why this is so remains a mystery (to me, at least).

Recently arriving Twin Otters have brought us an amazing variety of fresh fruit and vegetables, including apricots, bananas, kiwi fruit, pears and, my personal favourite, radishes. Even after two weeks of Jean Louis' exquisite French cuisine, there's nothing quite like a fresh radish.

This morning we saw some serious clouds for the first time in our two week visit here. Mind you, about half of them were created by the Twin Otter flying around, but there were some genuine natural ones too.


By lunch they were gone, and once again a crystal clear blue sky vaulted over Dome C. In fact, it was such a nice afternoon (mid minus-thirties), with almost zero wind, that we decided to move our flags and arrange them attractively across the field of view of the web camera. Last year we left the web camera running with the only the Australian flag in view. This year I think we'd like to project a more international image, with the French, Italian and US flags also flying to recognise the collaborators in the various aspects of the AASTINO project.

Moving the flags turned out to be surprisingly difficult, both physically and politically. Politically, we'd like all the flags at the same height, and equally prominent. However, the only ground that is in view of the web camera and which does not obscure the view of Concordia station has quite a slope on it. Not only that, but all the flagpoles are different lengths - which is hardly surprising given that they are just random lumps of wood. The physical problem arises because the snow around the AASTINO is rock hard (partly as a result of some of our guests preferring to roll up in bulldozers). In the end we got the flags more or less in a straight, horizontal line, with the Australian flag only slightly more prominent than the others. We will leave it to the many web cam devotees around the world to pass judgement on our efforts.

Amongst our final tasks is to install a dirty great fan in the AASTINO. One of the remarkable things we found this year is that the temperature within the AASTINO tends to stratify to an alarming extent. It can be +15 C at the ceiling, and -30 C on the floor. Unfortunately our really big 200 amp-hour storage batteries are on the floor (even we drew the line at putting them on the fuel tanks) and when they get too cold they stop working (basically because the electrolyte freezes). So, last year we created an ingenious series of tubes and fans configured to suck hot air from the ceiling and blow it out at floor level. But, as oft happens to best-laid plans, we found the fans were so noisy they prevented our acoustic radar from taking meaningful data. So, we had to turn them off most of the time.

A possible new solution, which we want to trial this summer, is to install a large (1.2 metre diameter) ceiling sweep fan. This will shift a whale of a lot of air, and hopefully do it quietly.

Unfortunately the ceiling of the AASTINO was not designed with such a fan in mind, and so the blades will be whirring around at more or less neck height - hence our reluctance to install it until we were just about to leave. We will leave a note on the door to remind the next AASTINO team, possibly phrased along the lines of: "Remove head or switch off fan before entering - your call".)

While most of what happens at Dome C is immensely sensible, I couldn't help noticing today that when the bulldozers go backwards they make a silly beeping sound. Since the driver has essentially the same visibility no matter what direction the machine is heading, I assume that someone must have done some tests and discovered that bulldozers make more of a mess of you when they run over you backwards than when they simply pummel you into the ground in a forwards direction. I find this hard to believe, given what happened to my snowmobile track.

With only one day to go we are painfully aware that we have not yet provided an intellectually satisfying theory as to why everything fell over in a heap on July 1. Trust me - we're working on it (especially Anna). Anna has procured some large sheets of cardboard, and is drawing up time-lines and graphs and diagrams and arrows. Tomorrow we will try a new approach, putting on different coloured de Bono hats, acting out some street theatre and maybe even looking at the log files some more. We're determined to get to the bottom of this.

John

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