Thursday, 15 September 2016

Your questions: the climate

Why is it always so cold?
Good question - there are several reasons! 
1) Antarctica is the world's highest continent (as well as the windiest, coldest, driest...) It has an average height above sea level of 2300m (about the height of Mt Ngauruhoe, 2287m), and temperatures drop as you go higher. 
2) It's surrounded by the cold Southern Ocean. In the northern hemisphere, big land masses like America and Europe trap the heat which gets transferred into warm ocean currents, but that doesn't happen in the empty southern ocean.  
3) The atmosphere above it is thinner and the snow and ice reflect back a lot of the sunlight. Plus, it gets less sunlight anyway than at the equator.  

Find out more details here  - it's really interesting!

Does it ever get warm? 
The booklet written for Scott Base's 50th anniversary says that the highest temperature recorded there was +7.5 degrees C in January 2002. That's pretty warm! (isn't it?) 

How cold is it actually?
Antarctica is the coldest continent. The lowest temperature ever recorded in the whole world was -89.6 degrees at Vostock Station. (Now that's definitely cold.) At Scott Base, a temperature of -57 degrees was recorded in August 1968.

How windy can it get?
Antarctica is the windiest continent. Gusts of wind of more than 300 km/hr have been recorded. At Scott Base, wind speeds of up to 196 km/hr have been recorded.

Does it rain?
It doesn't rain because it's too cold. Antarctica is the driest continent, and it's classed as a desert, which is a region with less than 25 cm of annual rainfall or precipitation (e.g. snow would count as precipitation if you measured how much water you'd get by melting it). In the middle of the continent, there isn't even much falling snow, so it has less annual precipitation than the Sahara desert. (In blizzards, snow might seem to be falling when it' s just being blown around by the wind.) But the snow that does fall doesn't melt, because of the cold, and so it gradually builds up over hundreds and thousands of years into thick ice sheets.

If you have a cold and a runny nose does your snot freeze over?
Yes! That's why you have big gloves with fluff on the outside as well as the inside. The outside fluff is used to wipe away (euw!) the "snot-sicles"

When you might need special extreme weather gloves!
Photo by Peter O'Sullivan, 2014-2015

Of course, that's on top of (literally) all the other pairs of gloves you get issued with - woollen gloves, woollen mittens, windproof gloves, leather gloves, waterproof gloves, polyprop gloves and spare waterproof glove liners... Just imagine how long it takes to put them all on, and how tricky it makes handling tools and cameras outdoors - and then if you take some off, you have to remember which pocket you put them in.

Mittens and gloves for Antarctic conditions!
©Antarctica New Zealand Pictorial Collection [1988-1989]

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