Airborne multi-axis DOAS measurements of tropospheric SO2 plumes in the Po-valley, Italy P. Wang1,4, A. Richter1, M. Bruns1, J. P. Burrows1, R. Scheele2, W. Junkermann3, K.-P. Heue4, T. Wagner4, U. Platt4, and I. Pundt4 1Institute of Environmental Physics, University of Bremen, Germany 2Royal Netherlands Meteorological Institute (KNMI), De Bilt, the Netherlands 3Research Center Karlsruhe, IMK-IFU, Garmisch-Partenkirchen, Germany 4Institute of Environmental Physics, University of Heidelberg, Germany
Abstract. During the second FORMAT (FORMaldehyde as A Tracer of oxidation in the troposphere)
campaign in 2003 the airborne multi-axis DOAS instrument (AMAXDOAS) performed
scattered-light spectroscopic measurements of SO2 over the city of Mantova
and the power plant Porto Tolle, both situated in the Po-valley, Northern Italy.
The SO2 vertical columns and emission flux were derived from two days of
measurements, 26 and 27 September 2003. The SO2 emission flux from the power
plant Porto Tolle was calculated to 1.93×1025 molec s-1 on
26 September and in good agreement with official emission data, which quote
2.25×1025 molec s-1. On 27 September the measured flux was
much lower (3.77×1024 molec s-1) if ECMWF wind data are used,
but of comparable magnitude (2.4×1025 molec s-1) if the
aircraft on-board wind measurements are utilised. Official emission
data was 2.07×1025 molec s-1 indicating only a small
change from the previous day. Over the city of Mantova,
the observed SO2 vertical columns were 1.1×1016 molec cm-2
and 1.9×1016 molec cm-2 on 26 and 27 September,
respectively. This is in good agreement with ground-based measurements
of 5.9 ppbv and 10.0 ppbv which correspond to
1.2×1016 molec cm-2 and
2.2×1016 molec cm-2 if a
well mixed boundary layer of 500m altitude is assumed.
Citation: Wang, P., Richter, A., Bruns, M., Burrows, J. P., Scheele, R., Junkermann, W., Heue, K.-P., Wagner, T., Platt, U., and Pundt, I.: Airborne multi-axis DOAS measurements of tropospheric SO2 plumes in the Po-valley, Italy, Atmos. Chem. Phys., 6, 329-338, doi:10.5194/acp-6-329-2006, 2006.