Sunset and Things in the Air

2006-02-19

It took me a few days of getting up unusually early but with the help of last night's BBQ (yes, outside, at -15) and following garage-nightclub I'm now back to my normal bed-until-eleven Sunday routine. The BBQ was held to celebrate our nearing the end of the season, as this could be the last weekend before the summer crew roll back onto the ship. So there was dancing, unlikely looking cocktails, doof-doof music and not so many people at lunch today.

Recently everything has been up in the air, except for the sun, which has, for the first time, started dipping below the horizon. On good days this lights up the sky and the base, bringing out oranges and reds, and throwing shadows into the distance. On other days, though, things are flatter, with midnight being much like noon except a bit duller. Darkness hasn't crept over the ice yet but threatens to descend soon.

So, first thing in the air this week was a weather balloon. We launch one of these every day so it reaches its maximum height around 1200 GMT. The balloons carry a small set of sensors (called a sonde) which broadcast back temperature, pressure and humidity data along with a GPS position, which is received by a radio rig at the station. Eventually, as the balloon gets higher and higher, the pressure outside the balloon drops, so that it eventually bursts its thin skin and plummets back to earth. We never recover the balloons which can travel a long way after their launch, but think the information they bring back about the environment is worth a small amount of litter. Eventually the data is sent through to the Met office in the UK, where it is used as input to forecasting models, and for longer term climate research.

Next into the air was me, on a short sightseeing flight in the area around the base. We flew off the skiway and along the coast. Passing icebergs and identifying the holes they'd left behind. Then we headed inland to the real coast of Antarctica, reacing the Hinge Zone, where giant glaciers stretch into the distance, crossed with cracks and crevasses, eventually dropping chunks of ice and snow into the sea. Where we are these chunks cannot escape and gradually coalesce into the smooth ice shelf, slowly pushed out to sea by the mass of ice behind, until eventually breaking off as icebergs. The scale of the continent is hard to manage, with the plateau rising slowly away into the distance, finally meeting the horizon a hundred miles away and six thousand feet higher. The ripples on the ice seem small, like drifts of snow on a footpath, until the airplane's small shadow races from crest to crest. Then back to the base, a set of small dots against a featureless canvass, stretched forever beneath us. It's easy to forget, from day to day, just how remote the station is, enclosed in emptiness and all alone on the ice.

Finally, on Saturday, we spent the afternoon on a test flight for our Helium blimp. This is at the base to conduct monitoring of low level ozone depletion events during the (Austral) spring. These will happen while we're cloaked in darkness, so we had a go at filling and flying the blimp while we could still see what we were doing. We pumped it up with three cylinders of Helium, squeezed it out from the tent it will live in, and flew it twenty meters into the air before reeling it back down. When we use it in anger it will go a couple of thousand meters into the air, taking ozone measurements as it rises.

Saturday turned out to be a very busy day as Dave, our Comms manager, came back from his medical trip to the Falklands. We've missed him while he was off on his holiday, and welcomed him back with a rapidly rehearsed performance on the Samba drums he left behind. I think we pulled it off ok, and made up for any small slips with volume and enthusiasm. All in all a happy homecoming, with smiles and hugs all round.

SHARE towers glint in the sunlight