849 posts 5/25/2016 4:21 am
Last Read: 5/27/2016 4:28 am
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WAITING FOR NOCTILUCENT CLOUDS Every year in late May, noctilucent clouds, NLCs gather over Earth's north pole where they remain, rippling hypnotically, until the end of Arctic summer. NLCs are, by far, Earth's highest clouds. Seeded by meteoroids, they float in a thin layer ~83 km above the planet's surface. With the beginning of the season upon us, NASA's AIM spacecraft is monitoring the Arctic for signs of electric blue.
This is called a "daily daisy." It assembles scans from AIM's Cloud Imaging and Particle Size (CIPS) instrument into an ensemble picture of the Arctic. Noctilucent clouds would appear as wispy filaments crisscrossing the Arctic Circle. You can see the daily daisy updated every 24 hours right here on Spaceweather.
So far AIM's daily daisy is empty, no NLCs. There has been one ground-based sighting that suggests the season might already be underway. We will know for sure when AIM spots the first Arctic NLCs of 2016 from space.
Taken by Ronny Tertnes on July 24, 2015 @ Bergen, Norway
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