Hamburg 2009 – wissenschaftliches Programm
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UP: Fachverband Umweltphysik
UP 10: Poster: Umweltphysik
UP 10.25: Poster
Donnerstag, 5. März 2009, 17:48–19:00, VMP 9 Poster
Retrieval of Aerosol Profiles using MAX-DOAS — •Selami Yilmaz, Udo Friess, and Ulrich Platt — Institute of Environmental Physics, University of Heidelberg, Germany
Using Multi Axis Differential Absorption Spectroscopy (MAX-DOAS) measurements of trace gases with a known vertical profile, like the oxygen-dimer O4, it is possible to retrieve information on atmospheric aerosols. Based on the optimal estimation method, we have developed an algorithm which fits simultaneously measured O4 optical densities at several wavelengths and elevation angles to values simulated by a radiative transfer model. Retrieval parameters are aerosol extinction profile and optical properties. In the scope of the EU funded project EUSAAR we have developed a new kind of a DOAS instrument, which uses three miniature spectrometers to cover a wide wavelength range (290-790nm), enabling to capture all absorption bands of O4. Additionally, it is possible to point to any direction in the sky with a 2D telescope unit which is connected to the spectrometers via fiber optics.
In May 2008, an intercomparison campaign with established aerosol measurement techniques took place in Cabauw/Netherlands, where simultaneous DOAS, LIDAR, Sun photometer and Nephelometer measurements were performed. We present first results of selected days from this period. The optical properties of aerosols retrieved by the DOAS technique show very good qualitative agreement with the established measurement techniques demonstrating the progress towards our goal of establishing the MAX-DOAS technique for retrieving optical properties of atmospheric aerosols.