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Titel |
Nitric acid trihydrate nucleation and denitrification in the Arctic stratosphere |
VerfasserIn |
J.-U. Grooß, I. Engel, S. Borrmann, W. Frey, G. Günther, C. R. Hoyle, R. Kivi, B. P. Luo, S. Molleker, T. Peter, M. C. Pitts, H. Schlager, G. Stiller, H. Vömel, K. A. Walker, R. Müller |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 2 ; Nr. 14, no. 2 (2014-01-29), S.1055-1073 |
Datensatznummer |
250118321
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Publikation (Nr.) |
copernicus.org/acp-14-1055-2014.pdf |
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Zusammenfassung |
Nitric acid trihydrate (NAT) particles in the polar stratosphere have been
shown to be responsible for vertical redistribution of reactive nitrogen
(NOy). Recent observations by Cloud–Aerosol Lidar with Orthogonal
Polarization (CALIOP) aboard the CALIPSO satellite have been explained in
terms of heterogeneous nucleation of NAT on foreign nuclei, revealing this to
be an important formation pathway for the NAT particles. In state of the art
global- or regional-scale models, heterogeneous NAT nucleation is currently
simulated in a very coarse manner using a constant, saturation-independent
nucleation rate. Here we present first simulations for the Arctic winter
2009/2010 applying a new saturation-dependent parametrisation of
heterogeneous NAT nucleation rates within the Chemical Lagrangian Model of
the Stratosphere (CLaMS). The simulation shows good agreement of chemical
trace species with in situ and remote sensing observations. The simulated polar stratospheric cloud (PSC)
optical properties agree much better with CALIOP observations than those
simulated with a constant nucleation rate model. A comparison of the
simulated particle size distributions with observations made using the
Forward Scattering Spectrometer Probe (FSSP) aboard the high altitude
research aircraft Geophysica, shows that the model reproduces the observed
size distribution, except for the very largest particles above 15 μm diameter. The vertical NOy redistribution caused by the
sedimentation of the NAT particles, in particular the denitrification and
nitrification signals observed by the ACE-FTS satellite instrument and the
in situ SIOUX instrument aboard the Geophysica, are reproduced by the
improved model, and a small improvement with respect to the constant
nucleation rate model is found. |
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