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| Titel |
Dehydration, denitrification and ozone loss during the Arctic winter 2015/2016: Simulations with the Chemistry-Climate Model EMAC and comparison to Aura/MLS and GLORIA observations |
| VerfasserIn |
Farahnaz Khosrawi, Oliver Kirner, Bjoern-Martin Sinnhuber, Sören Johansson, Michael Höpfner, Michelle L. Santee, Gloria Manney, Lucien Froidevaux, Jörn Ungermann, Peter Preusse, Felix Friedl-Vallon, Roland Ruhnke, Wolfgang Woiwode, Hermann Oelhaf, Peter Braesicke |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250148778
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| Publikation (Nr.) |
 EGU/EGU2017-13065.pdf |
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| Zusammenfassung |
| The Arctic winter 2015/2016 has been one of the coldest stratospheric winters in recent years.
A stable vortex formed already in early December and the early winter has been exceptionally
cold. Cold pool temperatures dropped below the Nitric Acid Trihydrate (NAT) existence
temperature, thus allowing Polar Stratospheric Clouds (PSCs) to form. The low temperatures
in the polar stratosphere persisted until early March allowing chlorine activation and
catalytic ozone destruction. Satellite observations indicate that sedimentation of
PSC particles have led to denitrification as well as dehydration of stratospheric
layers. Nudged 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)
campaign. POLSTRACC was a HALO mission (High Altitude and LOng Range
Research Aircraft) aiming on the investigation of the structure, composition and
evolution of the Arctic Upper Troposphere Lower Stratosphere (UTLS). 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 were investigated. In this presentation, an overview of the
chemistry and dynamics of the Arctic winter 2015/2016 as simulated with EMAC will
be given. Chemical-dynamical processes such as denitrification, dehydration and
ozone loss will be investigated. Comparisons to satellite observations by the Aura
Microwave Limb Sounder (Aura/MLS) as well as to airborne measurements with the
Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA)
performed onboard of HALO during the POLSTRACC campaign show that the EMAC
simulations are in good agreement with observations (differences generally within
±20%). However, larger differences between model and simulations are found e.g. in
the areas of denitrification. Both, model simulations and observation show that in
2015/2016 ozone loss was quite strong, but not as strong as in 2010/2011 while
denitrification and dehydration were so far the strongest in the Arctic stratosphere. |
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