South Pole Diaries 1995    

   


3rd February 1995

From Michael Ashley.....

As of this morning there are no aircraft on the continent capable of landing at the South Pole (the last one succumbed to a mechanical problem during the night). Luckily we have four years supply of food available at the South Pole station, although I suspect that after three years there would be a certain lack of variety.

The carpenters have completed the mounting box for IRPS, and Bob Pernic and John transported it out to the Pomerantz Building in a Spryte (a vehicle with tractor treads). We then spent 30 minutes winching it onto the roof, and positioning it ready to take IRPS.

Bob Pernic is using a lathe to make a dewar safety plug for us, and we contemplated swapping the drawing of the safety plug for engineering drawings of an LC-130 so that we can fly out of here. If anyone could make an LC-130 out of spare parts, Bob could. This is not too far from the truth - Bob's hobby is building small airplanes.

The mains power in the Pomerantz Building is very noisy - we have seen some incredible spikes. A small computer line-filter helps somewhat, but we are still getting spikes that are capable of interfering with our motor drivers. I track down a small (30 kg) unused UPS (Uninteruptable Power Supply) in the nearby Astro Building, and with the owner's permission, transport it by sled back to the Pomerantz Building.

The inner can of IRPS is now on the pump, and the detector temperature and vacuum pressure drop nicely. After flashing the detector, John and I begin a long series of calibration experiments to measure the performance of IRPS, and ensure that everything is working. Our homemade black-body source works just fine - by filling it with outside snow we get a temperature of -14C, with an ice slurry we get exactly 0C, and with the hottest water that the coffee machine can muster we get 67C (John tried every imaginable heating device in the building, ranging from hair driers and power resistors, to soldering irons, but could only manage an extra 2 degrees C). By 5am we have all the data we think we could possibly need. I try to send the data back to Michael Burton at UNSW, but the satellite has dipped below the horizon, so it will have to wait until tomorrow.

Incidentally, Michael Burton has been performing an invaluable role back in Sydney giving us advice on calibration measurements and feeding us reduced data from IRPS. John refers to Michael as ``our sea level brain'', a comment on the deleterious effect of altitude on mental agility.

By 7pm two of the LC-130s in Antarctica have been repaired, just in time for one of them to cause John and I to wait 20 minutes on the edge of the skiway (which bisects the line between the Pomerantz Building and the dome) while it landed. The other one comes in just as Jean Vernin is about to launch his balloon at 10:30pm, forcing Jean to stand out in the cold holding his 3-m diameter balloon and payload for 10 minutes. The air is thick with LC-130s.

Jean's balloon launch is very successful. He is getting temperature, pressure, humidity, and CT (a measurement of microthermal temperature fluctuations) up to 20km or so. This is the first time that microthermal measurements have been made in Antarctica over the full path-length through the atmosphere. Jean's initial impression of the data is that the atmosphere is remarkably free of turbulence, and even the inversion layer at 200m appears to be relatively non-turbulent. By the end of the winter we should have data from 25 of these balloon launches, and Jean should be able to make some very interesting quantitative comparisons between the South Pole and sites such as Mauna Kea and Chile.

Michael Ashley (with contributions from John Storey)