POLAR STRATOSPHERIC CLOUDS: Around the Arctic Circle, veteran sky
watchers are reporting a remarkable outbreak of polar stratospheric
clouds (PSCs). Floating high above Earth's surface in the normally
transparent stratosphere, PSCs have filled the sky with brilliant
colors that rival the aurora borealis. Some longtime residents of
northern Sweden say it's the best display they've ever seen, continuing
a trend in recent years of intensifying PSC activity.
edition of Spaceweather.com to view photos of the outbreak and to learn
more about these must-see wonders of the Arctic.
Above: Polar stratospheric clouds over Kiruna, Sweden, photographed by Mia Stålnacke on Feb. 13, 2017.
Browse the photo gallery for more sightings