Archive for the ‘Weather’ Category

When the going gets tough, the tough go camping

Wednesday, June 25th, 2008

It’s the middle of winter in Antarctica, the temperature has just dropped below -40°C, and it’s pitch dark outside.  What do you do?  Well, you pitch your tent, of course!

Not wanting to let the opportunity to emulate the great explorers slip by, Daleen, Morgan and I spent the night camping near the base.  To add to the ambience, I took a copy of Aspley Cherry-Garrard’s “The Worst Journey in the World (an epic tale of a winter sledging journey in Antarctica alomst 100 years ago) and read passages aloud to the amusement of the others.

Despite having three people in a two-man expedition tent, the cold soon invaded everything, and although we were warm in double down sleeping-bags the temperature in the tent dropped to -32°C, which left every surface covered in ice crystals.

Although there was initially no wind, by the next day a storm was moving in and the wind rapidly picked up to 60 knots (110km/h), buffeting the tent continuously and eunsuring a constant fine rain of ice.  Eventually, it was not the weather but empty stomachs and full bladders forced us back to the base, leaving the tent pegged down and snow-picketed but at the mercy of the elements.  The shape was distorting in the wind,but she stood firm.

New temperature record!

Tuesday, June 24th, 2008

The picture tells the story :)  This is the coldest temperature recorded at SANAE IV since 2000.

Rare cloud sighting

Monday, June 23rd, 2008

We were very lucky today to spot not one but two rare atmospheric phenomena today – nacreous and noctilucent clouds. Nacreous clouds are found in the stratosphere 15-25km above the surface of the Earth, and are thus high above other ‘normal’ cloud types. They are usually only seen in polar regions when the sun is below the horizon but reflects off the high clouds. The colours are beautiful and shimmering, reminiscent of an aurora. In the photo above, the nacreous clouds are the faint blue pattern on the lower left side. (The white band on top right is the noctilucent cloud – see below).

Noctilucent (or polar mesospheric) clouds are so high they have been labelled as being ‘on the edge of space’, between 80 and 120km above the planet. They are typically blue or white and are seen to shine before dawn and after dusk – or in the polar night when the sun is 6-16° below the horizon. Their origin is an unsolved mystery, as theoretically there should be no ice or water at this level. One theory (by far my favourite) is that dust and ice is shed by small meteors as they enter the planet’s atmosphere… quite something to look at glowing clouds in the dark sky and think they are formed from extraterrestrial ice :) The noctilucent clouds are easily visible in the photo above as a glowing white band.