South Pole Diaries 1998/99



Wednesday 13th January

From John Storey.....

This morning we put Jessica's nylon snow cover on the sodar antenna, attached all the little springs that hold it down, and spent a couple of hours taping up all the little holes where ice crystals might get in. It now looks exceeding smart with aluminium tape everywhere and the handsome colour-coordinated silver nylon cover. Webcam devotees will already have noted that the antenna is now installed in pride of place on the roof of the AASTO, just to the right of the entrance door. (By the way, "sodar" stands for sonic radar. The data reduction package is called SOD_IT. Or at least, if it's not, it should be.)

Lurking under that shiny cover are 52 piezoelectric transducers (the infamous "hooters") that can generate a sound level of 87dB 200metres away. Fortunately the beams are sent straight up or 30 degrees from the zenith. The sidelobes that come out horizontally at ground level are 40dB down, which is still loud but not offensive. It can't be heard inside the MAPO or ASTRO buildings, and is *just* audible from the cargo area in front of the Dome. However, it is a tad noisy *inside* the AASTO...

By early afternoon we had it merrily beeping, singing its little heart out with the sodar song. We seem to be measuring to 600 metres altitude without any problems, which is just beaut. It's also hooked up to the supervisor computer via port 2006. We can talk to it via telnet, but have the "Narrabri" problem that the frog-DOS wants to interpret the RS232 bytes in its own peculiar way. Daniel says that mcba can fix this particular problem in a flash, and possibly already has in a pharlap script somewhere. We await instructions.

It looks like the simplest thing is to leave the sodar powered up the whole time. The noise could then be turned on and off via a cron script on pharlap. The only disadvantage of this is that the hard disc on the IBM laptop will be running continuously. I confess to not having gotten around to designing a remote on/off switch, but did throw a passing glance at the switched 110V outlet on the back of the webcam.

Speaking of which, the webcam is working brilliantly, but the temperature in its little housing is up to 34C. Does anyone know why this might be? There's also only one perspex dome in place - I guess that's fine but not quite as energy efficient as with two.

Abu has now been switched off as it's clearly not going to get cold enough. Al Fowler is walking around looking depressed, waiting for Al Harper to turn up with the new cold head.

I've recorded the sodar song on my Mac in preparation for creating a .wav audio file on our home page. This will allow folk around the world to experience the delight and pleasure of an optimised echo-sensing tone sequence. Ambitious web surfers may also like to play it through their hifi at terrifying volume, thus truly recreating the sodar experience and provoking involuntary flight instabilities in passing birds.

Peter Gillingham has spent the day machining up new pieces for the tip-tilt secondary. He's resurrected the incorrectly made Invar backing plate that everyone else said would be too much work to fix. Peter has also cast his expert eye over the G-tower: "mostly good, but the stiffness is compromised by the poor pin-joints at the end of the struts". He's even come up with what I consider to be the most plausible theory so far on why vibration is mysteriously coupled from the MAPO building to the SPIREX telescope - as a sheer mode through the long canvas strips that seal the floor.

Meanwhile there's been an outbreak of graffiti on the wall of the solar-powered dunny, as various people attempt to prove or disprove the existence of god. The alt.toilet.religion discussion group has yet to go on-line.

The 18th to 26th no-fly period appears to be a reality, and confronts me with the difficult choice of leaving the Pole early before everything's finished, or getting home too late to stop the School of Physics collapsing in a big heap. Unless a major problem occurs in the next couple of days, I think I'll leave here on Saturday (there are no pax flights on Sunday) in the hope of catching the last flight to ChCh on Monday the 18th.

We had another tour of the AASTO by folk from the AGO (Automated Geophysical Observatory) project. They were very impressed with our instruments which are clearly lots more fun than geophysical ones. They were completely blown away by Melinda's 24 hour webcam movie which demonstrates, unequivocally, that we are at the South Pole. They said I should make sure Melinda makes another one - maybe several so we can pick the best one - very soon. (Actually I'm making that last bit up.)


Wednesday 13th January

From Michael Burton.....

Greetings from the Pole!

Coming towards the end of my first full day here now. After 4 days in Christchurch things moved fairly quickly and I was through McMurdo with just an overnight and down to Pole. Temperature a mild -30 right now, and sunny conditions, though I have to say I haven't quite acclimatized as yet! The altitude always hits you when you first arrive, but by tomorrow I hope I will have adjusted and feel like some real work.

The delays in ChCh meant I missed the Scott's Hut race in McMurdo by 1 day, and also the most fabulous ice-halo display. The locals believe it may even be a world record for the most number of different halo forms (24) ever seen in a single display - have a look at (which will be up about half the day for you) to see some of the spectacular shots of what ice particles high in the atmosphere can produce.

Pole is as crowded as ever, with many new experiments, and some of the old, all sharing the space, together with a large complement of construction crew who are starting work on the New Pole Station (a 5 year project). I came down with 2 of my students, and John Storey and Peter Gillingham (AAO) are also here. We seem to have got one of the expts going (a SODAR, or acoustic radar) but there are some major problems with the infrared camera at the moment.

I must admit the sense of adventure coming here is not quite what it was in the past, this being my third trip now, but it still is an incredible place and we are a long way from home. 2 sets of adventurers have passed though, a French expedition who were on the final leg of the '3 Poles' (Everest, the North Pole and the South Pole) having skied here from Berkner Island, and a Dutch group who paraglided here (attach sails to your sleds). The latter group are actually trying to cross the continent and end up in McMurdo, but are probably too late already, and are looking like they need to be rescued! And we are expecting a Kiwi expedition
in a few days, lead by Peter Hillary, Edmund Hillary's son (who was, of course, here in 57, as well as in 97)




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