South Pole Diaries 1998/99



Thursday 14th January - Snow Storm

From John Storey.....

Last night lots of Hercules arrived when I was trying to get to sleep, and then I started dreaming about Hercules only to be woken up by another arriving. But the one I was dreaming about was even louder so it put me back to sleep again (I think).

When I awoke the station was in the midst of a snow storm, with a 36km/hr wind blowing at right angles to the runway and wind-blown snow going everywhere. Visibility was down to about 50 metres. They even closed the big doors at the front of the dome - something I've never seen before and in fact I didn't even know the doors existed. Bob Lowenstein was also surprised by the doors, as he hurtled down the big slope to the dome entrance on his skis...

Under normal summer conditions here, when the wind is low and the temperature above -30C, I'm quite comfortable walking around in my Rockports and with my hands retracted into the sleeves of my parka as a substitute for gloves. However today was a stark reminder of how quickly the weather can get very nasty, when nothing short of the full ECW gear will keep the elements out.

It was very pleasing to see *no* snow accumulation on the sodar antenna. As hoped, the cover shakes like a drum-head in the wind, and keeps itself completely free of snow. On the other hand the sodar doesn't work at all when it's windy. Daniel says it's because the noise of the flags flapping etc drowns out the echo.

Daniel and I made an insulated collar for the antenna so that its little bottom can be kept as warm as possible by the AASTO room heat.

Peter has finished machining up parts for the tip-tilt secondary and has reassembled it. He's also measured the weight of the mirror and the spring constant of our phosphor-bronze diaphragm spring, calculated the maximum acceleration of the mirror and adjusted the tension accordingly (ie, to about one tenth of what it was before). He has also beautifully documented all the details, setting new standards for the project.

Abu is sitting forlornly while we await the arrival of Al Harper and the new cold head. At last count they still hadn't left Christchurch.

I tried to get the Toshiba to work but without success. The power light doesn't come on and it makes no attempt to read the floppy. Technically speaking, it's stuffed.

I'm about to put the SBIG camera and X-Y stage and Vectra computer business together, and see if it all works. Al Fowler has zero confidence that I'll be able to figure it out - slightly more than I have. Actually it looks pretty straightforward, but I can't help wondering:

1. Why the "Z" motor on the X-Y-Z stage is loose,
2. What the spare translation stage is for.

Today the AASTO had a visit from a reporter from the Washington Post. He is writing a major article about Antarctic physics, so we gave him the full tour. He especially liked the webcam movie, and said he was very keen to see the new one that Melinda is making.

Thomas has contacted PI in Germany on our behalf and arranged for them to specially make a replacement PZT. This can be flown out to Christchurch in a couple of days, which is fantastically good news.

The latest addition to the upstairs lounge is - to my complete astonishment - an automatic ice-maker. That's something that's clearly going to be really useful here. I'm going to survey other US stations around the world to see if the lounge in Saudi Arabia has an automatic sand maker. Such a trend in completely superfluous appliances could lead to a fog machine for the London embassy and an aphrodisiac dispensing machine for the White House.

Matt has been initiated into the delicate art of dallas dangling, and has rewired the sensors to the "big" supervisor computer. The new wiring complies strictly with the definitive dallas dogma of the dallas-danglin' big daddy himself (mcba): ie a straight daisy chain with no branches, twisted shielded-pair cabling and 0.1 mu capacitors at every point where voltages might otherwise be tempted to get out of hand. It's also routed mostly away from other digital cables - as long as you don't count ethernet as digital. With luck it will work more reliably than last year's wiring, which was basically a carefully uncontrolled experiment to see
just how tolerant the dallas sensors really are. Here's the detailed dallas designation dope:

1400000008D34910 Flag pole (Australian), 1 metre above AASTO
3B00000008F1A510 AASTO ceiling next to air intake baffle
E800000008D42B10 Sodar baseplate

Since last summer the station has acquired a brand new Caterpillar tractor for dragging the snow grader and other things around. It's one of the modern curvy ones with rubber tracks and has been named, appropriately enough, "The Drag Queen". Caterpillar certainly seem to be the heavy machine of choice around here. As the bumper sticker says: "If it ain't a Cat, it's a dog."




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