Editing Inversion (meteorology) (section)

==Wave propagation==
[[File:mirage_principle.svg|thumb|Mirages due to differing air refractive indices, ''n'']]
===Light===
As the temperature of air increases, the [[refractive index|index of refraction]] of air decreases, a side effect of hotter air being less dense. Normally this results in distant objects being shortened vertically, an effect that is easy to see at sunset when the sun is visible as an oval. In an inversion, the normal pattern is reversed, and distant objects are instead stretched out or appear to be above the horizon, leading to the [[phenomenon]] known as a [[Fata Morgana (mirage)|Fata Morgana]] or [[mirage]].

Inversions can magnify the so-called "[[green flash]]"—a phenomenon occurring at sunrise or sunset, usually visible for a few seconds, in which the sun's green light is isolated due to dispersion.<ref>{{cite journal |last1=ben Aroush |first1=Tomer |last2=Boulahjar |first2=Saber |last3=Lipson |first3=Stephen G |title=Observing the green flash in the laboratory |journal=European Journal of Physics |date=13 December 2017 |volume=39 |issue=1 |page=2 |doi=10.1088/1361-6404/aa90f5 |s2cid=125714499 |url=https://iopscience.iop.org/article/10.1088/1361-6404/aa90f5/pdf |access-date=21 June 2022}}</ref> The shorter wavelength is refracted most, with the blue component of sunlight "completely scattered out by [[Rayleigh scattering]]", making green the first or last light from the upper rim of the solar disc to be seen.<ref>{{cite journal |last1=ben Aroush |first1=Tomer |last2=Boulahjar |first2=Saber |last3=Lipson |first3=Stephen G |title=Observing the green flash in the laboratory |journal=European Journal of Physics |date=13 December 2017 |volume=39 |issue=1 |page=2 |doi=10.1088/1361-6404/aa90f5 |s2cid=125714499 |url=https://iopscience.iop.org/article/10.1088/1361-6404/aa90f5/pdf |access-date=21 June 2022}}</ref>{{Clear|left}}

===Radio waves===
{{main|Super refraction}}
[[Very high frequency]] [[radio waves]] can be refracted by inversions, making it possible to hear [[FM radio]] or watch [[VHF low]]-band television broadcasts from long distances on [[fog]]gy nights. The signal, which would normally be [[refract]]ed up and away into space, is instead refracted down towards the earth by the temperature-inversion boundary layer. This phenomenon is called [[tropospheric ducting]]. Along coastlines during Autumn and Spring, due to multiple stations being simultaneously present because of reduced propagation losses, many FM radio stations are plagued by severe signal degradation disrupting reception.
In higher frequencies such as [[microwave]]s, such refraction causes [[multipath propagation]] and [[fading]].

===Sound===
When an inversion layer is present, if a sound or explosion occurs at ground level, the sound wave is [[Refraction|refracted]] by the temperature gradient (which affects sound speed) and returns to the ground. The sound, therefore, travels much better than normal. This is noticeable in areas around airports, where the sound of aircraft taking off and landing often can be heard at greater distances around dawn than at other times of day, and inversion thunder which is significantly louder and travels further than when it is produced by lightning strikes under normal conditions.<ref>Dean A. Pollet and Micheal M. Kordich, [https://apps.dtic.mil/sti/pdfs/ADA477220.pdf User's guide for the Sound Intensity Prediction System (SIPS) as installed at the Naval Explosive Ordnance Disposal Technology Division (Naveodtechdiv)]. Systems Department February 2000. DTIC.mil</ref>

====Shock waves====
The [[shock wave]] from an explosion can be reflected by an inversion layer in much the same way as it bounces off the ground in an air-burst and can cause additional damage as a result. This phenomenon killed two people in the [[Soviet Union|Soviet]] [[RDS-37]] [[nuclear test]] when a building collapsed.<ref>{{cite web| first=Wm. Robert| last=Johnston| title=RDS-37 Nuclear Test, 1955| url=http://www.johnstonsarchive.net/nuclear/tests/1955USSR-1.html| access-date=11 April 2014}}</ref><ref>{{cite web| title=RDS-37: The Soviet Hydrogen Bomb| url=http://www.atomicarchive.com/History/coldwar/p7_image.shtml| access-date=26 December 2015}}</ref>