The South Pole’s special blanket of clouds usually rolls in during late November and early December, just in time to give the Southern Hemisphere its very own light show for the holidays. But this year, NASA says that the South Pole’s annual noctilucent, or night-shining, cloud show arrived much sooner than expected, in mid-November. The noctilucent clouds provide clues to the mesosphere’s connections to other parts of the atmosphere, weather, and climate. They are summer phenomena, appearing above the Arctic in July and August and above the Antarctic in November and December.
http://www.csmonitor.com/Science/2016/1203/Why-is-a-blue-cloud-appearing-over-Antarctica
