 |
| Titel |
NAT-rock formation by mother clouds: a microphysical model study |
| VerfasserIn |
S. Fueglistaler, B. P. Luo, C. Voigt, K. S. Carslaw, Th. Peter |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 2, no. 2 ; Nr. 2, no. 2 (2002-05-15), S.93-98 |
| Datensatznummer |
250000479
|
| Publikation (Nr.) |
 copernicus.org/acp-2-93-2002.pdf |
|
|
|
|
|
| Zusammenfassung |
| 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
HNO3 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 10-4 cm-3
NAT-rocks with radii around 10 mm
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. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|