Clouds in Alaska skies

Noctilucent Clouds

Electric blue Noctilucent ("Night Shining" or "NLC's) clouds are the highest of the exotic clouds known to appear over the polar regions of Earth.

They exist at the 82 km layer of our mesosphere and will shine only when the sun is 6-16 degrees below the horizon. It is thought that Noctilucent clouds are made up of meteoric dust and ice particles but studies still continue today. These amazing fibrous structures are blasted and shaped by intense winds that have been measured as high as 300 mph and evolve like ocean waves across astronomical twilight.

Top: Denali is silhouetted during solar midnight as twilight fills with webs of silver-blue. The three images show the evolution within about fifteen minutes.

Bottom: The first two show an extremely large and expansive Noctilucent cloud structure over the northwestern Chugach Mountains, showing change in about ten minutes.

The last image shows the edge of a display from Prince William Sound which lies in the distant south of the other images … the further south the viewer, the less of the display will be seen.

The clouds appear in higher latitudes during the summer seasons of both the northern or southern hemispheres and are a stunning spectacle to witness.

All images © Dave Parkhurst