Here’s what a seasoned aurora photographer cherishes most when chasing sky swirls.Northern lights over a building in Greenland.Credit: nevereverro/Getty ImagesI felt like a lemming pacing in my glass-walled cabin, swishing in my snow pants from one scouting corner to the next. It was January in Ilulissat, Greenland, an iceberg-laden getaway above the Arctic Circle—and winter is my favorite time here. It brings extra hours of darkness for the nor…