A015-09
Quantifying CH4 coal mine emissions in Upper Silesia by passive airborne remote sensing observations with the MAMAP instrument during the CoMet campaign 2018
Monday, 7 December 2020: 05:54
Virtual
Sven Krautwurst1, Konstantin Gerilowski1, Jakob Borchardt1, Norman Wildmann2, Michal Galkowski3, Julia Marshall3, Alina Fiehn2, Anke Roiger2, Thomas Ruhtz4, Christoph Gerbig3, Justyna Swolkień5, Jarosław M. Nęcki6, John Philip Burrows FRS7, Andreas Fix2 and Heinrich Bovensmann1, (1)University of Bremen, Institute of Environmental Physics (IUP), Bremen, Germany, (2)Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany, (3)Max Planck Institute for Biogeochemistry, Biogeochemical Signals, Jena, Germany, (4)Free University of Berlin, Institute for Space Sciences, Berlin, Germany, (5)AGH University of Science and Technology, Faculty of Mining and Geoengineering, Kraków, Poland, (6)AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Kraków, Poland, (7)University of Bremen, Institute of Environmental Physics, Bremen, Germany
Abstract:
Methane (CH4) is, after carbon dioxide (CO2), the second most important anthropogenic greenhouse gas in our atmosphere. It also has an important role in future climate mitigation strategies due to its stronger greenhouse warming potential compared to that of CO2, despite its relatively short atmospheric lifetime. Consequently, knowledge about CH4 sources is essential to reduce its atmospheric abundance. For this reason, the CoMet (CO2 and Methane) campaign was executed attempting to quantify emissions of one of the largest CH4 emitting areas in Europe, the Upper Silesian Coal Basin (USCB, Poland), starting from single shafts over smaller clusters up to the entire basin, in May and June 2018. Methane emissions from that area, originating from more than 50 mining shafts distributed over around 60 x 40 km², reach over 500 ktCH4/yr. During the campaign various platforms (aircraft, car, stationary) and instruments (active and passive remote sensing, in-situ, wind lidar, FTIR) were deployed to achieve that goal.
Here, we will focus on the passive airborne remote sensing MAMAP (Methane Airborne MAPper) observations, which use absorption spectroscopy to infer atmospheric CH4 concentration gradients. These gradients were combined in a simple mass balance approach with wind information from three wind lidar stations deployed in the USCB to infer cross-sectional CH4 fluxes through different flight tracks located downwind of multiple mining shafts. The computed fluxes were assigned to specific shafts, or small clusters of them, and compared to annually reported and hourly measured CH4 emissions.
Averaged observed fluxes are between ~1 and 9 tCH4/hr for single clusters derived from multiple overflights on different days. Associated errors (1-sigma) are in the range of 15 to 45% of the respective averaged fluxes and largely depend on the number of available flight tracks and atmospheric conditions, e.g. prevailing wind speed. In total around 23 shafts (out of 54) were investigated, corresponding to around 40% of the total CH4 mining emissions in that area. A comparison to annually reported values has revealed that caution is required when upscaling observed fluxes to the full year due to possible temporal fluctuations in emissions as also indicated by hourly emission data.
