noctilucent

American  

[nok-tuh-loo-suhnt] / ˌnɒk təˈlu sənt /

adjective

Meteorology.

1. (of high-altitude clouds) visible during the short night of the summer.

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noctilucent British  

/ ˌnɒktɪˈluːsənt /

adjective

1. shining at night, usu. of very thin high altitude clouds observable in the summer twilight sky

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noctilucent Scientific  

/ nŏk′tə-lo̅o̅′sənt /

1. Luminous at night. The term is used especially to describe certain high atmospheric cloud formations visible during summer nights at high latitudes.

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Other Word Forms

• noctilucence
  noun

Etymology

Origin of noctilucent

First recorded in 1885–90; nocti- + lucent

Example Sentences

She said the frequency of noctilucent clouds in the past few days has been higher than ever observed in at least 15 years of observations by the AIM mission.

From Washington Post • Jul. 2, 2022

“Folks in the northern U.S. and Canada should absolutely be on the lookout for noctilucent clouds over the long weekend,” Cora Randall, a professor at the University of Colorado Boulder, said in an email.

From Washington Post • Jul. 2, 2022

Alan Tough spotted these rare noctilucent clouds in Elgin, Scotland.

From BBC • Jul. 30, 2011

It is thought that the increase in brightness and frequency of noctilucent clouds over past decades may be linked to global warming.

From BBC • Apr. 24, 2010

Like noctilucent clouds high above the cirrus belt.

From The Scarlet Lake Mystery by Goodwin, Harold L. (Harold Leland)