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Modélisation des aérosols et de leurs propriétés optiques sur l'Europe et l'Ile de France : Validation, sensibilité et assimilation de données

Abstract : Aerosols are a key component for studying the atmospheric composition. Actually, they have harmful sanitary consequences, modify the visibility and impact the radiative balance with a direct effect (absorption/scattering of light), a semi-direct effect (change of the temperature vertical profile) and a indirect effect (acting as cloud condensation nuclei). Aerosol modeling is a challenging issue, both at the physical and numerical levels. The objective of the PhD work is to evaluate the performances and the limitations of aerosol modeling systems at regional and continental scales. What is the robustness of the models and the comparisons with measured data ? What could be the contribution of data assimilation methods ? In a first part, a size-resolved aerosol model embedded in the Polyphemus platform is evaluated though a few regional cases (Europe and Île-de-France) and for a few databases. The indicators are the PM10 (particles with a diameter lower than 10 μm), chemical composition and granulometry. The model outputs have also been extended in order to enable comparisons with optical data (optical thickness, extinction coefficient) measured by photometers or lidars. A second part investigates the sensitivity of the aerosol model with respect to physical parametrizations and numerical methods. This sensitivity analysis is the preliminary step before the use of ensemble method for aerosol forecasts, which appears to be a promising approach. A last part deals with the possible improvement induced by with a data assimilation system. The optimal interpolation method has then been implemented to assimilate PM10 data at ground level. The impact of data assimilation for forecast is also evaluated.
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https://pastel.archives-ouvertes.fr/pastel-00004169
Contributor : Ecole Des Ponts Paristech <>
Submitted on : Friday, September 19, 2008 - 8:00:00 AM
Last modification on : Monday, October 19, 2020 - 11:07:50 AM
Long-term archiving on: : Friday, September 10, 2010 - 12:46:08 PM

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  • HAL Id : pastel-00004169, version 1

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Marilyne Tombette. Modélisation des aérosols et de leurs propriétés optiques sur l'Europe et l'Ile de France : Validation, sensibilité et assimilation de données. Sciences of the Universe [physics]. Ecole des Ponts ParisTech, 2007. English. ⟨pastel-00004169⟩

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