Part I: Seals teeth and whales ears - Scott Polar Research Institute ...

Chapter 8
Signy Island: Sea ice and weather
Iceberg with three towers.
T
he day we arrived at Signy in February it felt rather cold and we were
surprised to see the men on base moving around on shore in their shirtsleeves,
when we had piled on cold weather clothing! For the first few weeks after our
arrival we experienced air temperatures round about freezing point, changing
together with the wind strengths, as the depressions moved through. We
acclimatized very quickly and in a couple of weeks were shedding layers of clothing.
It got colder in March – to about -8°C by the middle of the month, with snowfalls
intermittently. We made daily ice observations, weather permitting, from the top of
Observation Bluff, but only an arc of view from Normanna Strait to Roberts Bluff
was visible. Some mornings there was heavy sleet or snow and visibility from the
ridge was limited to less than a mile. When our other interests took us up onto the ice
cap we took the opportunity to make additional wider sea ice observations. In those
early days there was usually a large concentration of grounded bergs around the
Robertson Islands and some large tabular bergs began moving up from the south,
but no pack ice.
In those two years, apart from our work, the most influential factor affecting us
was the weather. As well as a sub-weekly pattern there was a seasonal pattern. We
were living in the worst climate in the world, one moment it could be very warm,
then the temperature would drop like a stone as a cold front passed through. These
came with monotonous regularity, one passing through every few days as they
moved rapidly around the continent. We were in their track most of the year and the
only let up was during winter when the pack ice enveloped the island and caused the
depression to change track to the north of us, producing slightly better weather. In
the account that follows I have tried to indicate the monotonous regularity of the
weather patterns as we experienced them, and inevitably this tends to be
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