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| Titel |
Retrieval of Aerosol Profiles using Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) |
| VerfasserIn |
Selami Yilmaz, Udo Frieß, Arnoud Apituley, Bas Henzing, Holger Baars, Birgit Heese, Dietrich Althausen, Mariana Adam, Jean-Philippe Putaud, Paul Zieger, Ulrich Platt |
| 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 |
250042196
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| Zusammenfassung |
| Multi Axis Differential Absorption Spectroscopy (MAX-DOAS) is a well established
measurement technique to derive atmospheric trace gas profiles. Using 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 and relative intensities at several wavelengths and elevation angles to values
simulated by a radiative transfer model. Retrieval parameters are aerosol extinction profile
and optical properties such as single scattering albedo, phase function and Angström
exponent.
In 2008 and 2009 several intercomparison campaigns with established aerosol measurement
techniques took place in Cabauw/Netherlands, Melpitz/Germany, Ispra/Italy and
Leipzig/Germany, where simultaneous DOAS, lidar, Sun photometer and Nephelometer
measurements were performed.
Here we present results of the intercomparisons for cloud free conditions. The correlation of
the aerosol optical thickness retrieved by the DOAS technique and the Sun photometer shows
coefficients of determination from 0.96 to 0.98 and slopes from 0.94 to 1.07. The vertical
structure of the DOAS retrieved aerosol extinction profiles compare favourably with the
structures seen by the backscatter lidar. However, the vertical spatial development of the
boundary layer is reproduced with a lower resolution by the DOAS technique. Strategies for
the near real-time retrieval of trace gas profiles, aerosol profiles and optical properties will be
discussed as well. |
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