Direct observation of two dimensional trace gas distributions with an airborne Imaging DOAS instrument K.-P. Heue1, T. Wagner2, S. P. Broccardo3, D. Walter1, S. J. Piketh3, K. E. Ross4, S. Beirle2, and U. Platt1 1Institut für Umweltphysik (IUP), Universität Heidelberg, Heidelberg, Germany 2Max Planck Institut für Chemie, Mainz, Germany 3Climatology Research Group, University of the Witwatersrand, Johannesburg, South Africa 4Generation Environmental Management Department, Eskom Pty (Ltd), South Africa
Abstract. In many investigations of tropospheric chemistry information about the
two dimensional distribution of trace gases on a small scale (e.g. tens to hundreds of metres)
is highly desirable. An airborne instrument based on imaging Differential Optical Absorption
Spectroscopy has been built to map the two dimensional distribution of a series of relevant
trace gases including NO2, HCHO, C2H2O2, H2O, O4, SO2,
and BrO on a scale of 100 m.
Here we report on the first tests of the novel aircraft instrument over the industrialised
South African Highveld, where large variations in NO2 column densities in the immediate
vicinity of several sources e.g. power plants or steel works, were measured. The observed patterns
in the trace gas distribution are interpreted with respect to flux estimates, and it is seen that the
fine resolution of the measurements allows separate sources in close proximity to one another to
Citation: Heue, K.-P., Wagner, T., Broccardo, S. P., Walter, D., Piketh, S. J., Ross, K. E., Beirle, S., and Platt, U.: Direct observation of two dimensional trace gas distributions with an airborne Imaging DOAS instrument, Atmos. Chem. Phys., 8, 6707-6717, doi:10.5194/acp-8-6707-2008, 2008.