Submitted by Anonymous on Sun, 01/16/2011 - 15:34
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Glacial History in Antarctica

For how long in a day is there daylight?

Mon, 01/31/2011 - 16:58

Lesley Urasky

While I was in Antarctica, the sun was up 24-hours a day.  Instead of the sun traveling across the sky and setting each day, it circled around the horizon.   
On February 20, 2011 the sun will set for the first time in a long time in McMurdo.  On February 20, the sun will set at 1:47 a.m. and rise at 2:30 a.m. The sun won't be that far below the horizon so it will be twilight for 43 minutes.  Each day thereafter, the sun will set about 40 minutes earlier each day and rise about 39 minutes later each day.  So, each day gains about 80 minutes of darkness.  This darkness will eventually increase until it sets for the winter and McMurdo is in 24-hour darkness.