Annales Geophysicae
Annales Geophysicae
ANGEO
Articles | Volume 20, issue 5
Articles | Volume 20, issue 5
https://doi.org/10.5194/angeo-20-711-2002
© Author(s) 2002. This work is distributed under
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/angeo-20-711-2002
© Author(s) 2002. This work is distributed under
the Creative Commons Attribution 3.0 License.
Articles | Volume 20, issue 5
31 May 2002
 | 31 May 2002

An explanation for some fallstreak clouds

R. M. Worthington

Abstract. Fallstreak cirrus clouds are associated with super-saturated air, together with waves, instabilities and/or turbulence; however, their precise cause is usually uncertain. This paper uses already-published satellite, radiosonde and radar data, reanalysed to study some large fallstreaks which had been previously overlooked. The fallstreaks – up to 60 km long with a parent cloud 20 km wide – are caused by lifting and/or turbulence from a mountain wave, rather than, for example, Kelvin-Helmholtz instabilities. If turbulent breaking of mountain waves affects ice particle formation, this may be relevant for the seeder-feeder effect on orographic rain, and the efficiency of mountain-wave polar stratospheric clouds for ozone depletion.

Key words. Meteorology and atmospheric dynamics (turbulence; waves and tides) – Atmospheric composition and structure (cloud physics and chemistry)

How to cite. Worthington, R. M.: An explanation for some fallstreak clouds, Ann. Geophys., 20, 711–715, https://doi.org/10.5194/angeo-20-711-2002, 2002.