In other news Icelandair are increasing to 6 flights a week from February 03rd, Tuesday will be the only day without a flight. Doesn't appear to continue for Summer 16 which still shows 4 flights, but early days.
Late Winter / Early Spring is peak period for 'Northern Lights' tourism to Iceland. I understand that visitors have a statistically improved chance of witnessing the phenomenon at this time of year. It is big business for Icelandair at a time of year when they don't need as much capacity deployed on routes dominated by Summer demand. In Summer they will arrange schedules to best feed their US - Iceland - Europe model.