NAT-rock formation by mother clouds: a microphysical model study
Item
Title (Dublin Core)
NAT-rock formation by mother clouds: a microphysical model study
Description (Dublin Core)
Polar stratospheric clouds (PSCs) of type 1a or 1a-enh containing high number densities of nitric acid trihydrate (NAT) particles, can act as mother clouds for extremely large NAT particles, termed NAT-rocks, provided the air below the clouds is supersaturated with respect to NAT. Individual NAT particles at the cloud base fall into undepleted gas phase and rapidly accelerate due to a positive feedback between their growth and sedimentation. The resulting reduction in number density is further enhanced by the strong HNO<sub>3</sub> depletion within a thin layer below the mother cloud, which delays subsequent particles. This paper introduces the basic microphysical principles behind this mother cloud/NAT-rock mechanism, which produces 10<sup>-4</sup> cm<sup>-3</sup> NAT-rocks with radii around 10 <font face="Symbol" >mm</font> some kilometers below the mother cloud. The mechanism does not require selective nucleation and works even for a monodisperse particle size distribution in the mother cloud.
Creator (Dublin Core)
Fueglistaler, S.
Luo, B.P.
Voigt, C.
Carslaw, K.S.
Peter, Th.
Date (Dublin Core)
2018-06-29
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-2-93-2002
https://acp.copernicus.org/articles/2/93/2002/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
