An unusual occurrence happened in Ilulissat, which is the third largest settlement in Greenland with about 4,500 residents. This city is located about 200 miles north of the Arctic Circle on the west coast of the island.
The sun "rose" for the first time in 2011 on Tuesday, January 11th. Since this city is north of the Arctic Circle, there is nothing unusual with the sun not being visible near the winter solstice. What is unusual is the sun was not supposed to rise until two days later, on Thursday, January 13th.
Why did this happen? Scientists are saying that there are no astronomical reasons. Here are two possible explanations:
1) Scientists are hypothesizing that glacier levels located nearby have dropped and allowed to the sun to be visible sooner.
2) Another hypothesis is that there is an unusual concentration of methane gas in the atmosphere. This would have caused sunlight to bend in a way that made the sun visible to the city two days early. This bending of light is particularly important when the sun is low on the horizon (ie. sunrise or sunset). The sun barely rises in Ilulissat for a few minutes currently, so it is obviously very low on the horizon.
Here is a map of Greenland showing Ilulissat halfway down the west coast