 |
| Titel |
Lagrangian analysis of microphysical and chemical processes in the Antarctic stratosphere: a case study |
| VerfasserIn |
L. Liberto, R. Lehmann, I. Tritscher, F. Fierli, J. L. Mercer, M. Snels, G. Donfrancesco, T. Deshler, B. P. Luo, J.-U. Grooß, E. Arnone, B. M. Dinelli, F. Cairo |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 12 ; Nr. 15, no. 12 (2015-06-16), S.6651-6665 |
| Datensatznummer |
250119832
|
| Publikation (Nr.) |
 copernicus.org/acp-15-6651-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
We investigated
chemical and microphysical processes in the late winter in the Antarctic
lower stratosphere, after the first chlorine activation and initial ozone
depletion. We focused on a time interval when both further chlorine
activation and ozone loss, but also chlorine deactivation, occur.
We performed a comprehensive Lagrangian analysis to simulate the evolution of
an air mass along a 10-day trajectory, coupling a detailed microphysical box
model to a chemistry model. Model results have been compared with in situ and
remote sensing measurements of particles and ozone at the start and end
points of the trajectory, and satellite measurements of key chemical species
and clouds along it.
Different model runs have been performed to understand the relative role of
solid and liquid polar stratospheric cloud (PSC) particles for the
heterogeneous chemistry, and for the denitrification caused by particle
sedimentation. According to model results, under the conditions investigated,
ozone depletion is not affected significantly by the presence of nitric acid
trihydrate (NAT) particles, as the observed depletion rate can equally well
be reproduced by heterogeneous chemistry on cold liquid aerosol, with a
surface area density close to background values.
Under the conditions investigated, the impact of denitrification is important
for the abundances of chlorine reservoirs after PSC evaporation, thus
stressing the need to use appropriate microphysical models in the simulation
of chlorine deactivation. We found that the effect of particle sedimentation
and denitrification on the amount of ozone depletion is rather small in the
case investigated. In the first part of the analyzed period, when a PSC was
present in the air mass, sedimentation led to a smaller available particle
surface area and less chlorine activation, and thus less ozone depletion.
After the PSC evaporation, in the last 3 days of the simulation,
denitrification increases ozone loss by hampering chlorine deactivation. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|