Evaluation of simulated CO.sub.2 power plant plumes from six high-resolution atmospheric transport models

• Published in: Atmospheric chemistry and physics 2023-02, Vol.23 (4), p.2699
• Main Authors: Brunner, Dominik, Kuhlmann, Gerrit, Henne, Stephan, Koene, Erik, Kern, Bastian, Wolff, Sebastian, Voigt, Christiane, Jöckel, Patrick, Kiemle, Christoph, Roiger, Anke, Fiehn, Alina, Krautwurst, Sven, Gerilowski, Konstantin, Bovensmann, Heinrich, Borchardt, Jakob, Galkowski, Michal, Gerbig, Christoph, Marshall, Julia, Klonecki, Andrzej, Prunet, Pascal, Hanfland, Robert, Pattantyús-Ábrahám, Margit, Wyszogrodzki, Andrzej, Fix, Andreas
• Format: Article
• Language: English
• Subjects: Coal-fired power plants; Electric power-plants; Numerical weather forecasting; Planetary boundary layer; Power plants; Simulation methods; Tracers (Chemistry)
• ISSN: 1680-7316

Power plants and large industrial facilities contribute more than half of global anthropogenic CO.sub.2 emissions. Quantifying the emissions of these point sources is therefore one of the main goals of the planned constellation of anthropogenic CO.sub.2 monitoring satellites (CO2M) of the European Copernicus program. Atmospheric transport models may be used to study the capabilities of such satellites through observing system simulation experiments and to quantify emissions in an inverse modeling framework. How realistically the CO.sub.2 plumes of power plants can be simulated and how strongly the results may depend on model type and resolution, however, is not well known due to a lack of observations available for benchmarking. Here, we use the unique data set of aircraft in situ and remote sensing observations collected during the CoMet (Carbon Dioxide and Methane Mission) measurement campaign downwind of the coal-fired power plants at Belchatów in Poland and Jänschwalde in Germany in 2018 to evaluate the simulations of six different atmospheric transport models. The models include three large-eddy simulation (LES) models, two mesoscale numerical weather prediction (NWP) models extended for atmospheric tracer transport, and one Lagrangian particle dispersion model (LPDM) and cover a wide range of model resolutions from 200 m to 2 km horizontal grid spacing. At the time of the aircraft measurements between late morning and early afternoon, the simulated plumes were slightly (at Jänschwalde) to highly (at Belchatów) turbulent, consistent with the observations, and extended over the whole depth of the atmospheric boundary layer (ABL; up to 1800 m a.s.l. (above sea level) in the case of Belchatów). The stochastic nature of turbulent plumes puts fundamental limitations on a point-by-point comparison between simulations and observations. Therefore, the evaluation focused on statistical properties such as plume amplitude and width as a function of distance from the source. LES and NWP models showed similar performance and sometimes remarkable agreement with the observations when operated at a comparable resolution. The Lagrangian model, which was the only model driven by winds observed from the aircraft, quite accurately captured the location of the plumes but generally underestimated their width. A resolution of 1 km or better appears to be necessary to realistically capture turbulent plume structures. At a coarser resolution, the plumes disperse too quickly,