Friday, December 14, 2012

South Pole weather and climate


I thought it might be interesting for you to know a little bit more about the weather and climate here. The official South Pole station guide says: “The average annual temperature at the South Pole is -49.5°C (-57.1°F), with a record low temperature of -82.8° C (-117.0°F) in June 1982 and a record high of -12.3°C (+9.9°F) in December 2011. The extremely dry environment limits annual snowfall. However, a relatively constant wind speed of 5-15 knots accounts for the snow drifting common to inland Antarctic stations. The surrounding terrain is virtually flat, except for shallow waves of sastrugi (small snowdrifts).”

We had unusual warm temperatures here at the Pole since a few weeks. The temperatures are around -25°C (roughly -14°F) which is warm enough that I really don’t want to put on my heavy down jacket. I have several layers on when I go outside, long johns, my wind-fly pants, two pairs of socks, a long-sleeved shirt, a fleece, the light red jacket, a hat, my ski goggles, a face mask or a tube scarf, a pair of glove liners (so that I can take the thick gloves off and take pictures with my camera without freezing my fingers off), and a thick pair of gloves. Lately I had either the jacket open, the scarf off or even the gloves off, because it was so warm. Not that I am complaining! At least I don’t freeze then.  :)

The annual precipitation is about 10 inches here (and that value even is a combination of drifted snow and ice and precipitation), which is really not very much. Most of it does not even fall as snow, but as tiny ice crystals. Sometimes, if the temperature drops, you can see ice crystals grow directly on the snow surface, without even falling from the sky. The humidity is not really high here either (roughly 60% on average – which is not much given the fact that it is relatively cold here), which results then in a super, super dry air inside the station, where temperatures are clearly higher and therefore the air would be able to hold more moisture. It can be as low as 1%, and normally does not go above the single digits, which pulls all your curls out of your hair, dry clothes on the line in minutes, and makes your nose bleed after a few days of living here. Even worse than Boulder!

I took some pictures of snow (and the sastrugi mentioned earlier) because, honestly, there is not really much else in the area around the station you could take a picture of… The snow drifts have sometimes cool shapes, and you can clearly see the preferred wind direction. And even tiny ice crystals on the snow surface are visible. I should probably mention that the snow here is so dry, that there is no possibility at all to have a snowball fight, or even of building a snowman. And if you walk through snow beside the most traveled paths, it sounds like you are walking through Styrofoam. Very crunchy and crisp.



No comments:

Post a Comment