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At Mawson during the summer the temperature can get up to 5°C on a still day, and usually doesn't go below about -10°C. During winter the temperature stays below -10°C and can get down to -36°C. These temperatures are quite mild compared to other Antarctic stations such as the Russian station 'Vostok' where temperatures of -89°C have been recorded. Even so, combined with wind chill anywhere in Antarctica can become very dangerous very quickly if you are not suitably protected from the effects of the cold and the wind. Blowing wind over skin has the effect of cooling the body down further than the temperature of the air alone. This is called wind chill. Air at -20°C, and blowing at 60kph has effective temperature of -50°C. In my experience so far the effects of the wind impact's most on our daily life. The power of the wind Until I arrived in Antarctica my favourite weather display was a rain storm with lightning and thunder. I really love the displays of these weather extremes and the feeling of insignificance that it imparts on me. Now in Antarctica I have witnessed the power of the Blizzard. Sir Douglas Mawson was spot on in describing Antarctica as the 'Home of the Blizzard'. Blizzards are the name given to the combination of hurricane force winds and blowing snow. Winds are classified as 'Hurricane force' when they exceed 118 kph and there are no more categories above this speed. At Mawson we regularly get winds that are classed "Strong gale'. The most common wind speed is between 37 to 80 kph, but there are times in the day or night when the wind can drop right off to dead calm. One minute it can be blowing a gale strength and within a few minutes the wind is just a gentle breeze. The greatest display of the wind that I have ever seen was during a blizzard a few weeks ago. Over a period of a few days the winds increased from the typical Mawson "strong gale" bringing with it thick blowing snow. The winds kept increasing until late in the night the average wind speed was 131 kph, and repeated strong gusts were measured to 200kph. Visibility during the night was down to less than 2 metres and it became too dangerous to go outside - even in an emergency such as fire. Earlier in the night during the Blizzard, when the winds were at about 110 kph, we had a fire alarm in the ANARESAT building. Luckily there was no fire and the alarm had probably only been set off by static electricity. Fire alarms and fires by themselves are dangerous in Antarctica because of the difficulty in obtaining large quantities of flowing water to fight them. In Blizzards our ability to fight fires is greatly diminished because we cannot easily get to the location of fire, let alone take fire fighting equipment to fight the fire. We have a specially equipped "Fire Hagglunds" which is setup with all the equipment of a normal fire engine. The problem in a Blizzard is that taking the Fire Hagg outside to fight the fire would probably result in the Fire Hagg being blown over on it's side. We would also have no way to direct the water at the fire or to extinguish the fire with the wind fanning the flames and blowing the water or foam away before it had reached the fire. It situations like this, we would not be able to fight a fire and it would have to be left to burn out or until the winds abated. Many buildings with important equipment in them such as the Power House and the ANARESAT building have Halon dump systems which flood the building with Halon gas and smother the fire.
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