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mahatmakanejeeves

(57,489 posts)
Tue Jun 11, 2019, 04:12 PM Jun 2019

Noctilucent cloud sightings have been pouring in from the western half of the nation.

There was a “huge outbreak” of rare noctilucent clouds over the weekend with sightings in ten states and parts of Europe:



Replying to @capitalweather
NW Wisconsin Sunday night ~10pm. https://www.facebook.com/groups/greatlakesaurorahunters/permalink/3299533730072306/



Noctilucent cloud



Noctilucent clouds over Kuresoo bog, Viljandimaa, Estonia

Abbreviation: NLC/PMC
Altitude: 76,000 to 85,000 m (250,000 to 280,000 ft)
Classification: Other
Precipitation cloud?: No

Noctilucent clouds, or night shining clouds, are tenuous cloud-like phenomena in the upper atmosphere of Earth. They consist of ice crystals and are only visible during astronomical twilight. Noctilucent roughly means "night shining" in Latin. They are most often observed during the summer months from latitudes between 50° and 70° north and south of the Equator. They are visible only during local summer months and when the Sun is below the observer's horizon, but while the clouds are still in sunlight. Recent studies suggests that increased atmospheric methane emissions produce additional water vapor once the methane molecules reach the mesosphere - creating, or reinforcing existing noctilucent clouds.

They are the highest clouds in Earth's atmosphere, located in the mesosphere at altitudes of around 76 to 85 km (47 to 53 mi). They are too faint to be seen in daylight, and are visible only when illuminated by sunlight from below the horizon while the lower layers of the atmosphere are in Earth's shadow.

General

Noctilucent clouds are not fully understood and are a recently discovered meteorological phenomenon. No confirmed record of their observation exists before 1885, although they may have been observed a few decades earlier by Thomas Romney Robinson in Armagh. Doubts now surround Robinson's out-of-season records, following observations, from several points around high northern latitudes, of NLC-like phenomena following the Chelyabinsk superbolide entry in February 2013 (outside the NLC season) that were in fact stratospheric dust reflections visible after sunset.

Noctilucent clouds can form only under very restricted conditions during local summer; their occurrence can be used as a sensitive guide to changes in the upper atmosphere. They are a relatively recent classification. The occurrence of noctilucent clouds appears to be increasing in frequency, brightness and extent.
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Noctilucent cloud sightings have been pouring in from the western half of the nation. (Original Post) mahatmakanejeeves Jun 2019 OP
This message was self-deleted by its author Chin music Jun 2019 #1
yikes...looks like methane is to blame FirstLight Jun 2019 #2
We had a massive show of these clouds Wellstone ruled Jun 2019 #3

Response to mahatmakanejeeves (Original post)

FirstLight

(13,360 posts)
2. yikes...looks like methane is to blame
Tue Jun 11, 2019, 04:27 PM
Jun 2019

which can be an indicator that Climate Change is definitely beyond the runaway point...

 

Wellstone ruled

(34,661 posts)
3. We had a massive show of these clouds
Tue Jun 11, 2019, 05:51 PM
Jun 2019

around six AM yesterday. And yes they seem to pop up more frequently in the last five years or so. Yesterday AM we had 57 degrees and about 40% humidity with a slight breeze coming out of Death Valley Area just as the Sun came up.

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