EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

First airborne in situ SO2 observations of two coal-fired power plants in Serbia and Bosnia-Herzegovina: Potential for top-down emission estimate and satellite validation 

Theresa Klausner1, Heidi Huntrieser1, Heinfried Aufmhoff1, Robert Baumann1, Alina Fiehn1, Klaus-Dirk Gottschaldt1, Pascal Hedelt2, Predrag Ilić5, Patrick Jöckel1, Sanja Mrazovac Kurilić3, Diego Loyola2, Ismail Makroum1, Mariano Mertens1, Zorica Podraščanin4, and Anke Roiger1
Theresa Klausner et al.
  • 1Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
  • 2Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Methodik der Fernerkundung, Oberpfaffenhofen, Germany
  • 3University Union-Nikola Tesla, Faculty of Ecology and Environmental Protection, Belgrade, Serbia
  • 4University of Novi Sad, Department of Physics, Faculty of Sciences, Novi Sad, Serbia
  • 5Institute for Protection and Ecology of the Republic of Srpska, Banja Luka, Bosnia-Herzegovina

Sulfur dioxide (SO2) is known as a major air pollutant harmful to human health. Furthermore, it is a precursor gas of sulfate aerosol, which exerts a direct negative radiative forcing and thus leads to climate cooling. Anthropogenic SO2 sources are primarily associated with the combustion of sulfur-rich fossil fuels. While the operation of flue gas desulfurization devices has led to large SO2 reductions in western Europe, a hotspot of anthropogenic SO2 sources remains in the Balkan region as recently observed from space by the TROPOMI instrument on the Sentinel-5P satellite. Large coal-fired power plants with no or only incomplete SO2 removal cause these high emissions.

Targeting these strong emitters, the DLR Falcon 20 aircraft was equipped with an isotopically on-line calibrated Chemical Ionization Ion Trap Mass Spectrometer (CI-ITMS) to obtain detailed in situ SO2 observations during the METHANE-To-Go-Europe aircraft campaign in autumn 2020. These SO2 measurements were complemented by in situ observations of greenhouse gases (CO2, CH4), aerosol number concentrations, and other short-lived pollutants (CO, NO, NOy). Two flights, on November 2nd and 7th 2020, focused on characterizing the pollution plumes downwind of two coal-fired power plants located in Bosnia-Herzegovina (Tuzla) and Serbia (Nikola Tesla), respectively. These power plants belong to the ten strongest SO2 emitters in Europe, and according to the World Health Organization, both countries are among the most polluted ones in Europe.

We present a detailed analysis of the two DLR Falcon flights with strongly enhanced SO2 mixing ratios (exceeding 50 ppb), which were observed at low flight altitude (<1 km). Respective flight patterns were designed to allow for the evaluation of the TROPOMI vertical SO2 column densities, and both flights were performed during cloud-free conditions. The airborne measurements and satellite data will also be complemented by hourly ground-based SO2 measurements near both power plants. In addition, measurements are combined with state-of-the art model simulations from (i) the regional atmospheric chemistry climate model MECO(n); (ii) the atmospheric transport and dispersion model HYSPLIT; and (iii) the chemistry coupled Weather Research and Forecasting model WRF-Chem to improve the emission quantification of these power plants.

How to cite: Klausner, T., Huntrieser, H., Aufmhoff, H., Baumann, R., Fiehn, A., Gottschaldt, K.-D., Hedelt, P., Ilić, P., Jöckel, P., Kurilić, S. M., Loyola, D., Makroum, I., Mertens, M., Podraščanin, Z., and Roiger, A.: First airborne in situ SO2 observations of two coal-fired power plants in Serbia and Bosnia-Herzegovina: Potential for top-down emission estimate and satellite validation , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5912,, 2021.

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