Lady Aurora

Part 2: Lady Aurora was dancing in the sky. Just after I went to bed around 22h30, Conny knocked on my door saying that bright Northern Lights are visible outside. Within 5 minutes I was dressed and ready to go. I already saw through the kitchen window (my bedroom was next to the kitchen) vivid green stripes that went up sky-high., Because we didn’t want to lose much time, we decided to go to a quiet (icy) road just outside the village. For over 2 hours we were treated with an immense visual spectacle! It definitely was my lucky day!
There is a lot of information on the Internet about photographing Northern Lights. But I did not found anything about a good setting for the White Balance (WB). I started with WB = 3000 K, but I soon found out that WB = 4200 K (Automatic WB) gives much better results. Of course, I photograph in RAW format so WB can always be adjusted afterwards, but it always a good idea to with good settings in the field already. Does anybody can help me out on this?

* Canon EOS 5D Mark II, 16-35mm/f4 @ 16mm; ISO-1600, f4, 10s.
* Canon EOS 5D Mark II, 16-35mm/f4 @ 16mm; ISO-1600, f4, 10s.