<p>There is a measurable decay of airglow radiance during the night. Here's an example measurement of <span class="math-container">$\mathrm{OH}^-$</span> infrared emissions (<span class="math-container">$\sim2\,\mathrm{\mu m}$</span> wavelength) done on Mauna Kea in ref. 1:</p>
<p><a href="https://i.sstatic.net/kjuXh.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/kjuXh.png" alt="" /></a></p>
<h3>References</h3>
<ol>
<li>S. K. Ramsay, C. M. Mountain, T. R. Geballe, Non-thermal emission in the atmosphere above Mauna Kea, <em>Monthly Notices of the Royal Astronomical Society</em>, Volume 259, Issue 4, December 1992, Pages 751–760, <a href="https://doi.org/10.1093/mnras/259.4.751" rel="nofollow noreferrer">https://doi.org/10.1093/mnras/259.4.751</a></li>
</ol>

CC BY-SA 4.0
2023-05-14T09:59:05.993Z
2023-05-14T09:59:05.993Z
Ruslan
<p><a href="https://en.wikipedia.org/wiki/Airglow" rel="noreferrer">Airglow</a> is caused, among other factors, by recombination of atoms ionized during the day. This makes me think that during the night concentration of these ions should reduce, lowering intensity of airglow.</p>

<p>But is this reduction of intensity actually measurable, or is the recombination so slow as to preserve airglow at almost the same intensity?</p>

CC BY-SA 4.0
2019-02-27T23:19:15.913Z
That's a good question, but you're thinking from the perspective of a local observer on Earth. There is work published by several observations satellites that observe Earth in the UV and provide global views on airglow from space. Probably you can find an answer there?
AtmosphericPrisonEscape
<atmosphere><upper-atmosphere>
Does airglow intensity systematically change during the night?
Ruslan
# Does airglow intensity systematically change during the night?

(Asked by: username_0 on 2019-02-27)

[Airglow](https://en.wikipedia.org/wiki/Airglow) is caused, among other factors, by recombination of atoms ionized during the day. This makes me think that during the night concentration of these ions should reduce, lowering intensity of airglow.

But is this reduction of intensity actually measurable, or is the recombination so slow as to preserve airglow at almost the same intensity?

**Tags:** atmosphere, upper-atmosphere

> **Comments:**
> **username_1**: That's a good question, but you're thinking from the perspective of a local observer on Earth. There is work published by several observations satellites that observe Earth in the UV and provide global views on airglow from space. Probably you can find an answer there?  

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## 1 answers

### Answer by username_0 on 2023-05-14. Score: 1 | Accepted answer

There is a measurable decay of airglow radiance during the night. Here's an example measurement of $\mathrm{OH}^-$ infrared emissions ($\sim2\,\mathrm{\mu m}$ wavelength) done on Mauna Kea in ref. 1:

[![](https://i.sstatic.net/kjuXh.png)](https://i.sstatic.net/kjuXh.png)

### References

1. S. K. Ramsay, C. M. Mountain, T. R. Geballe, Non-thermal emission in the atmosphere above Mauna Kea, *Monthly Notices of the Royal Astronomical Society*, Volume 259, Issue 4, December 1992, Pages 751–760, <https://doi.org/10.1093/mnras/259.4.751>


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