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UP: Fachverband Umweltphysik

UP 12: Poster: Neuartige Messverfahren der Umweltphysik

UP 12.2: Poster

Dienstag, 27. März 2007, 14:00–15:00, Poster C

Tomographic LP-DOAS measurements of 2D trace gas distributions above the city of Heidelberg, Germany — •Denis Pöhler, Andreas Hartl, and Ulrich Platt — Institute of Environmental Physics, University of Heidelberg, Germany

LP-DOAS (Long Path-Differential Optical Absorption Spectroscopy) is a well known remote sensing technique for measuring the average concentration of tropospheric trace gases along extended light paths in the open atmosphere. In order to retrieve information of the spatial trace gas distribution tomographic LP-DOAS measurements are useful. They combine the measurement along several intersecting light paths with tomographic inversion techniques and allow 2 and 3 dimensional retrieval of trace gas distributions.

In a campaign in Heidelberg, Germany, a measurement set-up encompassing a total of 18 horizontal light paths by using three *Multibeam* LP-DOAS instruments is being tested. In the wavelength range from 285nm to 365nm the average concentrations of the trace gases NO2, SO2, O3, HCHO and HONO along each light path could be retrieved with a temporal resolution below 15 minutes. The first evaluated data from winter 2005/06 show high accuracy for NO2 and SO2 mean concentrations. They allow deriving for these trace gases two-dimensional distributions above the city. Different emission sources varying strongly in space and time can be identified. The results demonstrate that tomographic DOAS measurements can be used to study emissions and transport of trace gases and can be used to evaluate models predicting the air quality.