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| Titel |
Targeted observations of chemical constituents |
| VerfasserIn |
Nadine Goris, Hendrik Elbern |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250042853
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| Zusammenfassung |
| Adaptive observations taken in well defined targeted areas can -in combination with
data assimilation techniques- reduce the initial condition uncertainty and decrease
forecast errors. Reasonable target areas are unstable system modes, which can be
detected with the help of singular vectors. The singular vectors of a numerical model
identify the directions of fastest perturbation growth over a finite time interval and are
therefore associated with dynamically sensitive model states. In order to determine
unstable chemical species, a singular vector algorithm was implemented into the
three-dimensional chemical transport model EURAD-IM (which features 3- and
4-dimensional data assimilation). Since the evolution of chemical species is not only
sensitive to initial conditions but also to emissions, the singular vector technique was
utilised to study the influence of both emissions and initial conditions of different
species.
The singular vector algorithm was first applied within a box model to investigate the
influence of initial perturbations in volatile organic compounds and nitrogen oxydes on the
final concentration of ozone. Moreover the dependence of singular vectors on the initial
conditions and the length of the simulationsinterval was analysed. The results demonstrate
that the algorithm clearly identifies sensitive chemical constituents. Furthermore
the 4-dimensional singular vector technique was evaluated using data from the
ZEPTER-2 campaign. The study states a positive impact of targeted observations. |
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