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| Titel |
Chemistry and dynamics of the Arctic winter 2015/2016: Simulations with the Chemistry-Climate Model EMAC |
| VerfasserIn |
Farahnaz Khosrawi, Ole Kirner, Bjoern-Martin Sinnhuber, Roland Ruhnke, Michael Hoepfner, Wolfgang Woiwode, Hermann Oelhaf, Michelle L. Santee, Gloria L. Manney, Lucien Froidevaux, Donal Murtagh, Peter Braesicke |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250126195
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| Publikation (Nr.) |
 EGU/EGU2016-5886.pdf |
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| Zusammenfassung |
| Model simulations of the Arctic winter 2015/2016 were performed with the atmospheric
chemistry-climate model ECHAM5/MESSy Atmospheric Chemistry (EMAC) for the
POLSTRACC (Polar Stratosphere in a Changing Climate) project. The POLSTRACC project
is a HALO mission (High Altitude and LOng Range Research Aircraft) that aims to
investigate the structure, composition and evolution of the Arctic Upper Troposphere Lower
Stratosphere (UTLS) in a changing climate. Especially, the chemical and physical processes
involved in Arctic stratospheric ozone depletion, transport and mixing processes in the UTLS
at high latitudes, polar stratospheric clouds as well as cirrus clouds are investigated. The
model simulations were performed with a resolution of T42L90, corresponding to a quadratic
Gaussian grid of approximately 2.8∘× 2.8∘ degrees in latitude and longitude, and 90 vertical
layers from the surface up to 0.01 hPa (approx. 80 km). A Newtonian relaxation technique of
the prognostic variables temperature, vorticity, divergence and surface pressure
towards ECMWF data was applied above the boundary layer and below 10 hPa, in
order to nudge the model dynamics towards the observed meteorology. During the
Arctic winter 2015/2016 a stable vortex formed in early December, with a cold pool
where temperatures reached below the Nitric Acid Trihydrate (NAT) existence
temperature of 195 K, thus allowing Polar Stratospheric Clouds (PSCs) to form. The
early winter has been exceptionally cold and satellite observations indicate that
sedimenting PSC particles have lead to denitrification as well as dehydration of
stratospheric layers. In this presentation an overview of the chemistry and dynamics of the
Arctic winter 2015/2016 as simulated with EMAC will be given and comparisons
to satellite observations such as e.g. Aura/MLS and Odin/SMR will be shown. |
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