0572062 20250526121147.620230522235959.9 10.5194/egusphere-egu23-12287 1 s. E cav_un_epca*0572061MunichThe European Geosciences Union2023 NH3 cav_un_auth*0363740 Evangeliou N. NO cav_un_auth*0267768 Tichý Ondřej UTIA-B Adaptivní systémy Department of Adaptive Systems AS AS Department of Adaptive Systems Ústav teorie informace a automatizace AV ČR, v. v. i. cav_un_auth*0419235 Eckhardt S. NO cav_un_auth*0450270 Balkanski Y. FR cav_un_auth*0450271 Hauglustaine D. FR http://library.utia.cas.cz/separaty/2023/AS/tichy-0572062.pdf In the present study, we use direct comparisons between the CrIS (Cross-track Infrared Sounder ) observations and model retrievals using the Least Squares with Adaptive Prior Covariance (LS-APC) algorithm, which reduces the number of tuning parameters in the method significantly using variational Bayes approximation technique. We constrain ammonia emissions over Europe over 2013–2020 and validate the results against ground-based observations from the EMEP (European Monitoring and Evaluation Programme). We find that emissions of ammonia decreased from 5431 Gg in 2013 to 3994 Gg in 2020 (-26%). Regionally, emissions declined by 38% in Central and Eastern Europe, 37% in Western Europe, 8% in Southern Europe and -17% in Northern Europe. cav_un_auth*0450272 EGU General Assembly 2023 20230423 20230428 Vídeň AT 2024 5 4 O 4o 20250526121147.6 PO https://hdl.handle.net/11104/0342938 1 S 2023 Soubory v repozitáři: 0572062.pdf SCOPUS PUBMED WOS cav_un_epca*0572061 EGU General Assembly 2023 Munich The European Geosciences Union 2023