High-resolution inverse modelling of European CH4 emissions using the novel FLEXPART-COSMO TM5 4DVAR inverse modelling system

0563169 - ÚVGZ 2023 RIV DE eng J - Journal Article
Bergamaschi, P. - Segers, A. - Brunner, D. - Haussaire, J. - Henne, S. - Ramonet, M. - Arnold, T. - Biermann, T. - Chen, H. - Conil, S. - Delmotte, M. - Forster, G. - Frumau, A. - Kubistin, D. - Lan, X. - Leuenberger, M. - Lindauer, M. - Lopez, M. - Manca, G. - Mueller-Williams, J. - O'Doherty, S. - Scheeren, B. - Steinbacher, M. - Trisolino, P. - Vítková, Gabriela - Kwok, C. Y.
High-resolution inverse modelling of European CH4 emissions using the novel FLEXPART-COSMO TM5 4DVAR inverse modelling system.
Atmospheric Chemistry and Physics. Roč. 22, č. 20 (2022), s. 13243-13268. ISSN 1680-7316. E-ISSN 1680-7324
R&D Projects: GA MŠMT(CZ) LM2018123
Institutional support: RVO:86652079
Keywords : atmospheric observations * data assimilation * N2O emissions * methane * CO2 * union
OECD category: Meteorology and atmospheric sciences
Impact factor: 6.3, year: 2022
Method of publishing: Open access
https://acp.copernicus.org/articles/22/13243/2022/

We present a novel high-resolution inverse modelling system (FLEXVAR) based on FLEXPART-COSMO back trajectories driven by COSMO meteorological fields at 7km x 7km resolution over the European COSMO-7 domain and the four-dimensional variational (4DVAR) data assimilation technique. FLEXVAR is coupled offline with the global inverse modelling system TM5-4DVAR to provide background mole fractions (baselines) consistent with the global observations assimilated in TM5-4DVAR. We have applied the FLEXVAR system for the inverse modelling of European CH4 emissions in 2018 using 24 stations with in situ measurements, complemented with data from five stations with discrete air sampling (and additional stations outside the European COSMO-7 domain used for the global TM5-4DVAR inversions). The sensitivity of the FLEXVAR inversions to different approaches to calculate the baselines, different parameterizations of the model representation error, different settings of the prior error covariance parameters, different prior inventories, and different observation data sets are investigated in detail. Furthermore, the FLEXVAR inversions are compared to inversions with the FLEXPART extended Kalman filter (FLExKF) system and with TM5-4DVAR inversions at 1 degrees x 1 degrees resolution over Europe. The three inverse modelling systems show overall good consistency of the major spatial patterns of the derived inversion increments and in general only relatively small differences in the derived annual total emissions of larger country regions. At the same time, the FLEXVAR inversions at 7km x 7km resolution allow the observations to be better reproduced than the TM5-4DVAR simulations at 1 degrees x 1 degrees. The three inverse models derive higher annual total CH4 emissions in 2018 for Germany, France, and BENELUX compared to the sum of anthropogenic emissions reported to UNFCCC and natural emissions estimated from the Global Carbon Project CH4 inventory, but the uncertainty ranges of top-down and bottom-up total emission estimates overlap for all three country regions. In contrast, the top-down estimates for the sum of emissions from the UK and Ireland agree relatively well with the total of anthropogenic and natural bottom-up inventories.
Permanent Link: https://hdl.handle.net/11104/0335207