I'm kinda curious to know what responses you get. One thing's for sure--it's going to be cold. And dark the entire day, too. (In Barrow, the sun sets sometime in November, I think, and doesn't rise until like February. I may be off on my months, but it does disappear below the horizon for an extended amount of time.)

Not sure on the cloudy-to-clear ratio. The chance of northern lights is likely to be as high as one in two (versus one in 10 or less in Anchorage). Believe it or not, Fairbanks lies closer to the middle of the aurora arc than does Barrow (Fort Yukon is even better, but it's hard to get to). See the aurora prediction site at the Geophysical Institute at UAF for some maps and information.

Have fun up there! Know you're saving a lot of money by booking it as an award--it's almost $600 to to book a round-trip from Anchorage to Barrow in December (hardly peak season). I can only imagine what it would be from SNA... (I just checked--$1260. Ugh...)