Microphysical modeling of the 1999-2000 Arctic winter: 3. Impact of homogeneous freezing on polar stratospheric clouds

Simulations of the 1999–2000 winter have tested the effect on polar stratospheric clouds (PSCs) of the homogeneous freezing of liquid ternary solutions into nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD). Proposed laboratory‐derived volume‐based and surface‐based homogeneous freezing r...

Full description

Saved in:
Bibliographic Details
Published in:Journal of Geophysical Research. D. Atmospheres 2004-05, Vol.109 (D10), p.D10201.1-n/a
Main Authors: Drdla, K., Browell, E. V.
Format: Article
Language:English
Subjects:
denitrification
Earth, ocean, space
Exact sciences and technology
freezing
polar stratospheric clouds
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Simulations of the 1999–2000 winter have tested the effect on polar stratospheric clouds (PSCs) of the homogeneous freezing of liquid ternary solutions into nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD). Proposed laboratory‐derived volume‐based and surface‐based homogeneous freezing rates have both been examined, including different assumptions about the extrapolation of laboratory measurements to atmospheric conditions. Widespread PSC formation and denitrification are possible in several of the scenarios examined. However, the simulations are all unable to explain the solid‐phase PSCs observed early in the 1999–2000 winter and are unable to reproduce the measured extent of vortex denitrification. These problems can both be attributed to the relatively cold temperatures, more than 5 K below the NAT condensation point, necessary for homogeneous freezing to be effective at producing solid‐phase PSCs. Therefore synoptic‐scale homogeneous freezing appears unlikely to be the primary mechanism responsible for solid‐phase PSC formation.
ISSN:0148-0227
2156-2202
DOI:10.1029/2003JD004352