Saturday, 12 September 2015

Airglow


Airglow
See those green stripes? That is airglow rippled by gravity waves which are disturbances in the troposphere. For example, wind flow over mountain ranges and thunderstorms like in this case. 

The airglow is the light of electronically and/or vibration-rotationally excited atoms and molecules 80 km or higher.

So, what's the difference between airglow and aurorae?
Aurorae are at similar heights and are also the light of excited atoms. There is a difference, however, auroral excitation is by collisions with energetic particles whereas daytime short wavelength solar radiation produces the airglow via chemical excitation of which electronically excited oxygen atoms are the main component.

Watch:
https://vimeo.com/dakotalapse

Know more:
http://www.atoptics.co.uk/highsky/airglow2.htm

#naturalphenomena   #airglow   #atmosphere   #troposphere   #science
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11 comments:

  1. Gizmo the Sane13 September 2015 at 00:23

    Beautiful and interesting! Thanks :)

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  2. Davor Maksimović13 September 2015 at 02:23

    You are amazing smart and beautiful girl .. thanks for share

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  3. Kenny Chaffin13 September 2015 at 04:40

    Gravity waves? I don't think so, we've been trying to detect them for decades now.

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  4. Corina Marinescu13 September 2015 at 04:45

    I was referring to the waves in fluid dynamics not general relativity.

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  5. Gizmo the Sane13 September 2015 at 04:48

    I read gravity waves (relativity) too. The scale does seem a bit large for that...

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  6. Corina Marinescu13 September 2015 at 04:50

    Where I come from there's a difference between gravity waves and gravitational waves ;)

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  7. Gizmo the Sane13 September 2015 at 05:05

    I remember these waves. When the height just passes the cloud base height, the water at the top of these waves would condense, forming waves.

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  8. Norman M.13 September 2015 at 06:53

    An scientific approach by increase or decrease rate of change (time)...

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  9. Sam Collett13 September 2015 at 07:01

    Turn the sky sea-blue, upside down and it could be ripples approaching a shoreline, with a sunset

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  10. Boris Borcic13 September 2015 at 08:35

    "auroral excitation is by collisions with energetic particles whereas daytime short wavelength solar radiation produces the airglow"... mhh, doesn't wave-particle duality mean that "energetic particles" and "short wavelength radiation" are the same thing?

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  11. Corina Marinescu13 September 2015 at 09:45

    Since I know there's a difference between radiative and collisional excitation as I'm sure you know.
    If the atom suffers a collision that causes an electron to jump from the lower to higher energy state it is called collisional excitation.
    If the electron captures a photon of energy hv corresponding to the energy difference between the two energy levels, and so jumps from the lower to higher energy state, it is called radiative excitation.
    Obviously the difference applies to the reverse processes as well (de-excitation).

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