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| Titel |
ICON-ART-ISO: Water isotopologues implemented in the chemistry- transport model ICON-ART |
| VerfasserIn |
Johannes Eckstein, Roland Ruhnke, Daniel Reinert, Stephan Pfahl |
| 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 |
250148501
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| Publikation (Nr.) |
 EGU/EGU2017-12761.pdf |
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| Zusammenfassung |
| Stable isotopes of water can help to understand processes that have influenced the
distribution of water in the atmosphere. Isotope enabled models, capable of simulating the
distribution of HDO and H218O, can be a very useful tool for understanding these
processes and the distribution of isotope ratios which are observed. We present
ICON-ART-ISO, the implementation of water isotopes into the chemistry-transport model
ICON-ART.
The core of this global model is the ICOsahedral Non-hydrostatic (ICON) modelling
framework (Zaengl et al, 2015 (Q. J. R. Meteorol. Soc.)), a joint development of the German
Weather Service (DWD) and the Max Planck Institute for Meteorology. The model system
ICON-ART (Aerosols and Reactive Trace gases, Rieger et al, 2015 (GMD)) is a two-way
coupled extension to ICON, which allows to study the influence of aerosols, trace gases and
their chemistry on the atmosphere. We set up ICON-ART-ISO within this framework,
profitting from the model infrastructure. We follow the implementation of COSMOiso (Pfahl
et al., 2012 (ACP)), the isotope-enabled version of the COSMO model, the predecessor of
ICON.
In order to include the isotopes in the model, the water cycle is doubled diagnostically
for each isotope. By the choice of physical parameters, these modelled isotopes
are set to HDO and H218O, but the simulation of a purely diagnostic H2O is also
possible.
Fractionation, i.e. the change of the isotope ratio changes during phase changes, is
considered in evaporation, grid-scale precipitation and convection. For the source of
evaporation, a constant isotope ratio is currently used. To consider grid scale precipitation, the
processes in the two-moment microphysical scheme by Seifert and Beheng, 2005
(Meteorol. Atmos. Phys.) are diagnostically applied to the isotopes. For convection, the
Tiedtke-Bechtold scheme (Bechtold et al., 2013 (JAS)) is used.
We present the current status of the model system. All processes have been implemented
and we show first validation results. We plan to investigate three tropical storms,
comparing with data from the ongoing measurement project CARIBIC (Civil Aircraft for
the Regular Investigation of the atmosphere Based on an Instrument Container). |
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