{"id":"https://openalex.org/W7215100231","doi":"https://doi.org/10.5194/acp-26-13743-2026","title":"Inferring European fossil fuel CO 2 emissions using TROPOMI NO 2 data and sector-based NO x : CO 2 emission ratios","display_name":"Inferring European fossil fuel CO 2 emissions using TROPOMI NO 2 data and sector-based NO x : CO 2 emission ratios","publication_year":2026,"publication_date":"2026-10-01","ids":{"openalex":"https://openalex.org/W7215100231","doi":"https://doi.org/10.5194/acp-26-13743-2026"},"language":"en","primary_location":{"id":"doi:10.5194/acp-26-13743-2026","doi":"https://doi.org/10.5194/acp-26-13743-2026","is_oa":true,"landing_page_url":"https://doi.org/10.5194/acp-26-13743-2026","pdf_url":"https://acp.copernicus.org/articles/26/13743/2026/acp-26-13743-2026.pdf","source":{"id":"https://openalex.org/S162708223","display_name":"Atmospheric chemistry and physics","issn_l":"1680-7316","issn":["1680-7316","1680-7324"],"is_oa":true,"is_in_doaj":true,"is_core":true,"listed_in":["anvur-scientific","cwts-core","doaj","dongbi-b","jufo-3","norway-2","oarl","poland-140","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310313756","host_organization_name":"Copernicus Publications","host_organization_lineage":["https://openalex.org/P4310313756"],"host_organization_lineage_names":["Copernicus Publications"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Atmospheric Chemistry and Physics","raw_type":"journal-article"},"volume":null,"type":"article","is_traditional":true,"indexed_in":["crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"gold","oa_url":"https://acp.copernicus.org/articles/26/13743/2026/acp-26-13743-2026.pdf","any_repository_has_fulltext":null},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5089482648","display_name":"Chl\u00f6e N. Schooling","orcid":"https://orcid.org/0000-0001-7892-9715","observed_orcids":["https://orcid.org/0000-0001-7892-9715"]},"institutions":[{"id":"https://openalex.org/I98677209","display_name":"University of Edinburgh","ror":"https://ror.org/01nrxwf90","country_code":"GB","type":"education","lineage":["https://openalex.org/I98677209"]}],"countries":["GB"],"is_corresponding":false,"raw_author_name":"Chl\u00f6e N. Schooling","raw_affiliation_strings":["University of Edinburgh (Edinburgh, United Kingdom)"],"raw_orcid":"https://orcid.org/0000-0001-7892-9715","affiliations":[{"raw_affiliation_string":"University of Edinburgh (Edinburgh, United Kingdom)","institution_ids":["https://openalex.org/I98677209"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5101440824","display_name":"Liang Feng","orcid":"https://orcid.org/0000-0002-4587-7020","observed_orcids":["https://orcid.org/0000-0002-4587-7020"]},"institutions":[{"id":"https://openalex.org/I98677209","display_name":"University of Edinburgh","ror":"https://ror.org/01nrxwf90","country_code":"GB","type":"education","lineage":["https://openalex.org/I98677209"]}],"countries":["GB"],"is_corresponding":false,"raw_author_name":"Liang Feng","raw_affiliation_strings":["School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom","institution_ids":["https://openalex.org/I98677209"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5024873052","display_name":"Ingrid Super","orcid":"https://orcid.org/0000-0001-8252-5983","observed_orcids":["https://orcid.org/0000-0001-8252-5983"]},"institutions":[{"id":"https://openalex.org/I148297040","display_name":"Netherlands Organisation for Applied Scientific Research","ror":"https://ror.org/01bnjb948","country_code":"NL","type":"nonprofit","lineage":["https://openalex.org/I148297040"]}],"countries":["NL"],"is_corresponding":false,"raw_author_name":"Ingrid Super","raw_affiliation_strings":["Department of Air Quality and Emissions Research, TNO, P.O.\u00a0Box\u00a080015, 3508\u00a0TA Utrecht, the Netherlands"],"raw_orcid":"https://orcid.org/0000-0001-8252-5983","affiliations":[{"raw_affiliation_string":"Department of Air Quality and Emissions Research, TNO, P.O.\u00a0Box\u00a080015, 3508\u00a0TA Utrecht, the Netherlands","institution_ids":["https://openalex.org/I148297040"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5021613819","display_name":"Paul I. Palmer","orcid":"https://orcid.org/0000-0002-1487-0969","observed_orcids":["https://orcid.org/0000-0002-1487-0969"]},"institutions":[{"id":"https://openalex.org/I4210128104","display_name":"National Centre for Earth Observation","ror":"https://ror.org/0375jbm11","country_code":"GB","type":"facility","lineage":["https://openalex.org/I141816643","https://openalex.org/I4210087105","https://openalex.org/I4210128104"]},{"id":"https://openalex.org/I98677209","display_name":"University of Edinburgh","ror":"https://ror.org/01nrxwf90","country_code":"GB","type":"education","lineage":["https://openalex.org/I98677209"]}],"countries":["GB"],"is_corresponding":false,"raw_author_name":"Paul I. Palmer","raw_affiliation_strings":["National Centre for Earth Observation (Leicester, United Kingdom)","University of Edinburgh (Edinburgh, United Kingdom)"],"raw_orcid":"https://orcid.org/0000-0002-1487-0969","affiliations":[{"raw_affiliation_string":"National Centre for Earth Observation (Leicester, United Kingdom)","institution_ids":["https://openalex.org/I4210128104"]},{"raw_affiliation_string":"University of Edinburgh (Edinburgh, United Kingdom)","institution_ids":["https://openalex.org/I98677209"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":3,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":{"value":1600,"currency":"EUR","value_usd":1725},"apc_paid":{"value":1600,"currency":"EUR","value_usd":1725},"fwci":0.0,"has_fulltext":true,"cited_by_count":0,"citation_normalized_percentile":{"value":0.62145034,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":null,"biblio":{"volume":"26","issue":"19","first_page":"13743","last_page":"13766"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11588","display_name":"Atmospheric and Environmental Gas Dynamics","score":0.9800000190734863,"subfield":{"id":"https://openalex.org/subfields/2306","display_name":"Global and Planetary Change"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T11588","display_name":"Atmospheric and Environmental Gas Dynamics","score":0.9800000190734863,"subfield":{"id":"https://openalex.org/subfields/2306","display_name":"Global and Planetary Change"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10075","display_name":"Atmospheric chemistry and aerosols","score":0.018200000748038292,"subfield":{"id":"https://openalex.org/subfields/1902","display_name":"Atmospheric Science"},"field":{"id":"https://openalex.org/fields/19","display_name":"Earth and Planetary Sciences"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T12916","display_name":"COVID-19 impact on air quality","score":0.00019999999494757503,"subfield":{"id":"https://openalex.org/subfields/2306","display_name":"Global and Planetary Change"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/fossil-fuel-co2-emissions","display_name":"fossil fuel CO2 emissions","score":0.9980000257492065},{"id":"https://openalex.org/keywords/no2-emissions","display_name":"NO2 emissions","score":0.5730000138282776},{"id":"https://openalex.org/keywords/tropomi","display_name":"TROPOMI","score":0.8820000290870667},{"id":"https://openalex.org/keywords/satellite-data-assimilation","display_name":"satellite data assimilation","score":0.8159999847412109},{"id":"https://openalex.org/keywords/ensemble-kalman-filter","display_name":"ensemble Kalman filter","score":0.9309999942779541},{"id":"https://openalex.org/keywords/geos-chem","display_name":"GEOS-Chem","score":0.972000002861023},{"id":"https://openalex.org/keywords/nox-chemistry","display_name":"NOx chemistry","score":0.5450000166893005},{"id":"https://openalex.org/keywords/seasonal-variation","display_name":"seasonal variation","score":0.5640000104904175},{"id":"https://openalex.org/keywords/european-emissions","display_name":"European emissions","score":0.8759999871253967},{"id":"https://openalex.org/keywords/orbiting-carbon-observatory-2","display_name":"OCO-2","score":0.7160000205039978},{"id":"https://openalex.org/keywords/biogenic-co2","display_name":"biogenic CO2","score":0.5929999947547913}],"concepts":[{"id":"https://openalex.org/C39432304","wikidata":"https://www.wikidata.org/wiki/Q188847","display_name":"Environmental science","level":0,"score":0.70660001039505},{"id":"https://openalex.org/C24552861","wikidata":"https://www.wikidata.org/wiki/Q2670177","display_name":"Data assimilation","level":2,"score":0.5738999843597412},{"id":"https://openalex.org/C68189081","wikidata":"https://www.wikidata.org/wiki/Q12748","display_name":"Fossil fuel","level":2,"score":0.557699978351593},{"id":"https://openalex.org/C91586092","wikidata":"https://www.wikidata.org/wiki/Q757520","display_name":"Atmospheric sciences","level":1,"score":0.5457000136375427},{"id":"https://openalex.org/C79334102","wikidata":"https://www.wikidata.org/wiki/Q3072268","display_name":"Ensemble Kalman filter","level":4,"score":0.45890000462532043},{"id":"https://openalex.org/C68709404","wikidata":"https://www.wikidata.org/wiki/Q1134475","display_name":"Flux (metallurgy)","level":2,"score":0.45419999957084656},{"id":"https://openalex.org/C2775840915","wikidata":"https://www.wikidata.org/wiki/Q3817528","display_name":"Plume","level":2,"score":0.45010000467300415},{"id":"https://openalex.org/C130047971","wikidata":"https://www.wikidata.org/wiki/Q289382","display_name":"Trace gas","level":2,"score":0.43479999899864197},{"id":"https://openalex.org/C47737302","wikidata":"https://www.wikidata.org/wiki/Q167336","display_name":"Greenhouse gas","level":2,"score":0.41100001335144043},{"id":"https://openalex.org/C143742823","wikidata":"https://www.wikidata.org/wiki/Q5513004","display_name":"GCM transcription factors","level":4,"score":0.3982999920845032},{"id":"https://openalex.org/C2994553857","wikidata":"https://www.wikidata.org/wiki/Q131123","display_name":"Atmospheric emissions","level":2,"score":0.3982999920845032},{"id":"https://openalex.org/C132651083","wikidata":"https://www.wikidata.org/wiki/Q7942","display_name":"Climate change","level":2,"score":0.3700999915599823},{"id":"https://openalex.org/C559116025","wikidata":"https://www.wikidata.org/wiki/Q131123","display_name":"Air pollution","level":2,"score":0.3587999939918518},{"id":"https://openalex.org/C168754636","wikidata":"https://www.wikidata.org/wiki/Q620920","display_name":"Climate model","level":3,"score":0.3546000123023987},{"id":"https://openalex.org/C125403950","wikidata":"https://www.wikidata.org/wiki/Q2111082","display_name":"Seasonality","level":2,"score":0.33660000562667847},{"id":"https://openalex.org/C153294291","wikidata":"https://www.wikidata.org/wiki/Q25261","display_name":"Meteorology","level":1,"score":0.3294999897480011},{"id":"https://openalex.org/C65440619","wikidata":"https://www.wikidata.org/wiki/Q177974","display_name":"Atmosphere (unit)","level":2,"score":0.32690000534057617},{"id":"https://openalex.org/C157286648","wikidata":"https://www.wikidata.org/wiki/Q846780","display_name":"Kalman filter","level":2,"score":0.32600000500679016},{"id":"https://openalex.org/C9075549","wikidata":"https://www.wikidata.org/wiki/Q40631","display_name":"Troposphere","level":2,"score":0.32280001044273376},{"id":"https://openalex.org/C537208039","wikidata":"https://www.wikidata.org/wiki/Q627","display_name":"Nitrogen","level":2,"score":0.3165999948978424},{"id":"https://openalex.org/C521259446","wikidata":"https://www.wikidata.org/wiki/Q58734","display_name":"Pollution","level":2,"score":0.31029999256134033},{"id":"https://openalex.org/C2776720842","wikidata":"https://www.wikidata.org/wiki/Q1337883","display_name":"Emission inventory","level":3,"score":0.3095000088214874},{"id":"https://openalex.org/C118365302","wikidata":"https://www.wikidata.org/wiki/Q4817115","display_name":"Atmospheric model","level":2,"score":0.30410000681877136},{"id":"https://openalex.org/C187691185","wikidata":"https://www.wikidata.org/wiki/Q2020720","display_name":"Grid","level":2,"score":0.28999999165534973},{"id":"https://openalex.org/C106131492","wikidata":"https://www.wikidata.org/wiki/Q3072260","display_name":"Filter (signal processing)","level":2,"score":0.2842999994754791},{"id":"https://openalex.org/C49204034","wikidata":"https://www.wikidata.org/wiki/Q52139","display_name":"Climatology","level":1,"score":0.2842000126838684},{"id":"https://openalex.org/C126314574","wikidata":"https://www.wikidata.org/wiki/Q2364111","display_name":"Air quality index","level":2,"score":0.28029999136924744},{"id":"https://openalex.org/C21200559","wikidata":"https://www.wikidata.org/wiki/Q7451068","display_name":"Sensitivity (control systems)","level":2,"score":0.275299996137619},{"id":"https://openalex.org/C203032635","wikidata":"https://www.wikidata.org/wiki/Q20962970","display_name":"NOx","level":3,"score":0.2694000005722046},{"id":"https://openalex.org/C111335779","wikidata":"https://www.wikidata.org/wiki/Q3454686","display_name":"Reduction (mathematics)","level":2,"score":0.26100000739097595}],"mesh":[],"locations_count":3,"locations":[{"id":"doi:10.5194/acp-26-13743-2026","doi":"https://doi.org/10.5194/acp-26-13743-2026","is_oa":true,"landing_page_url":"https://doi.org/10.5194/acp-26-13743-2026","pdf_url":"https://acp.copernicus.org/articles/26/13743/2026/acp-26-13743-2026.pdf","source":{"id":"https://openalex.org/S162708223","display_name":"Atmospheric chemistry and physics","issn_l":"1680-7316","issn":["1680-7316","1680-7324"],"is_oa":true,"is_in_doaj":true,"is_core":true,"listed_in":["anvur-scientific","cwts-core","doaj","dongbi-b","jufo-3","norway-2","oarl","poland-140","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310313756","host_organization_name":"Copernicus Publications","host_organization_lineage":["https://openalex.org/P4310313756"],"host_organization_lineage_names":["Copernicus Publications"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Atmospheric Chemistry and Physics","raw_type":"journal-article"},{"id":"doi:10.5194/egusphere-2026-1315","doi":"https://doi.org/10.5194/egusphere-2026-1315","is_oa":true,"landing_page_url":"https://doi.org/10.5194/egusphere-2026-1315","pdf_url":null,"source":null,"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"EGUsphere","raw_type":"posted-content"},{"id":"pmh:oai:doaj.org/article:cc612129ff454d75981ac953a1e886bd","doi":null,"is_oa":false,"landing_page_url":"https://doaj.org/article/cc612129ff454d75981ac953a1e886bd","pdf_url":null,"source":{"id":"https://openalex.org/S4306401280","display_name":"DOAJ (DOAJ: Directory of Open Access Journals)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Atmospheric Chemistry and Physics, Vol 26, Pp 13743-13766 (2026)","raw_type":"article"}],"best_oa_location":{"id":"doi:10.5194/acp-26-13743-2026","doi":"https://doi.org/10.5194/acp-26-13743-2026","is_oa":true,"landing_page_url":"https://doi.org/10.5194/acp-26-13743-2026","pdf_url":"https://acp.copernicus.org/articles/26/13743/2026/acp-26-13743-2026.pdf","source":{"id":"https://openalex.org/S162708223","display_name":"Atmospheric chemistry and physics","issn_l":"1680-7316","issn":["1680-7316","1680-7324"],"is_oa":true,"is_in_doaj":true,"is_core":true,"listed_in":["anvur-scientific","cwts-core","doaj","dongbi-b","jufo-3","norway-2","oarl","poland-140","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310313756","host_organization_name":"Copernicus Publications","host_organization_lineage":["https://openalex.org/P4310313756"],"host_organization_lineage_names":["Copernicus Publications"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Atmospheric Chemistry and Physics","raw_type":"journal-article"},"sustainable_development_goals":[{"score":1.0,"id":"https://metadata.un.org/sdg/13","display_name":"Climate action"}],"study_designs":[],"awards":[{"id":"https://openalex.org/G2559426217","display_name":null,"funder_award_id":"NE/R016518/1","funder_id":"https://openalex.org/F4320338155","funder_display_name":"National Centre for Earth Observation"},{"id":"https://openalex.org/G2975835067","display_name":null,"funder_award_id":"NE/R016518","funder_id":"https://openalex.org/F4320338155","funder_display_name":"National Centre for Earth Observation"},{"id":"https://openalex.org/G5231093629","display_name":null,"funder_award_id":"101082194","funder_id":"https://openalex.org/F4320334322","funder_display_name":"HORIZON EUROPE Framework Programme"},{"id":"https://openalex.org/G6385443491","display_name":"NCEO LTS-S","funder_award_id":"NE/R016518/1","funder_id":"https://openalex.org/F4320334631","funder_display_name":"Natural Environment Research Council"},{"id":"https://openalex.org/G937310267","display_name":null,"funder_award_id":"101082194","funder_id":"https://openalex.org/F4320338445","funder_display_name":"HORIZON EUROPE Climate, Energy and Mobility"}],"funders":[{"id":"https://openalex.org/F4320306101","display_name":"National Aeronautics and Space Administration","ror":"https://ror.org/027ka1x80"},{"id":"https://openalex.org/F4320309622","display_name":"Harvard University","ror":"https://ror.org/03vek6s52"},{"id":"https://openalex.org/F4320334322","display_name":"HORIZON EUROPE Framework Programme","ror":null},{"id":"https://openalex.org/F4320334631","display_name":"Natural Environment Research Council","ror":"https://ror.org/02b5d8509"},{"id":"https://openalex.org/F4320338155","display_name":"National Centre for Earth Observation","ror":"https://ror.org/0375jbm11"},{"id":"https://openalex.org/F4320338445","display_name":"HORIZON EUROPE Climate, Energy and Mobility","ror":null}],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W7215100231.pdf","grobid_xml":"https://content.openalex.org/works/W7215100231.grobid-xml"},"referenced_works_count":62,"referenced_works":["https://openalex.org/W632895101","https://openalex.org/W1973208866","https://openalex.org/W2018636632","https://openalex.org/W2027404493","https://openalex.org/W2034637484","https://openalex.org/W2069293643","https://openalex.org/W2102806954","https://openalex.org/W2112983045","https://openalex.org/W2121085229","https://openalex.org/W2130686417","https://openalex.org/W2138017294","https://openalex.org/W2138052188","https://openalex.org/W2139334033","https://openalex.org/W2141085693","https://openalex.org/W2159780518","https://openalex.org/W2170452673","https://openalex.org/W2183127047","https://openalex.org/W2533261859","https://openalex.org/W2547552060","https://openalex.org/W2599059974","https://openalex.org/W2613115809","https://openalex.org/W2763551617","https://openalex.org/W2766082071","https://openalex.org/W2901580848","https://openalex.org/W2922111312","https://openalex.org/W2941059881","https://openalex.org/W2967981435","https://openalex.org/W2968631756","https://openalex.org/W2975181041","https://openalex.org/W2980902968","https://openalex.org/W3010561629","https://openalex.org/W3013819707","https://openalex.org/W3036222531","https://openalex.org/W3040503344","https://openalex.org/W3098728056","https://openalex.org/W3129610671","https://openalex.org/W3160070731","https://openalex.org/W3180189734","https://openalex.org/W4210901135","https://openalex.org/W4221045243","https://openalex.org/W4280619712","https://openalex.org/W4283744773","https://openalex.org/W4309624415","https://openalex.org/W4360616169","https://openalex.org/W4388800951","https://openalex.org/W4392470609","https://openalex.org/W4392510212","https://openalex.org/W4400836406","https://openalex.org/W4405098773","https://openalex.org/W4406398043","https://openalex.org/W4408142269","https://openalex.org/W4411282998","https://openalex.org/W4411926390","https://openalex.org/W4412088301","https://openalex.org/W4415386761","https://openalex.org/W4416299875","https://openalex.org/W6944173343","https://openalex.org/W6962982485","https://openalex.org/W6967966691","https://openalex.org/W7117302974","https://openalex.org/W7125906128","https://openalex.org/W7165026194"],"related_works":["https://openalex.org/W4408433197","https://openalex.org/W4280619712","https://openalex.org/W2337139182","https://openalex.org/W4416299875","https://openalex.org/W4388415189","https://openalex.org/W3169409924","https://openalex.org/W4396554698","https://openalex.org/W7214082324","https://openalex.org/W7135385637","https://openalex.org/W4406333402"],"abstract_inverted_index":{"Abstract.":[0],"Accurate":[1],"monitoring":[2],"of":[3,88,120,223],"fossil":[4,215],"fuel":[5,216],"CO2":[6,49,201],"(ffCO2)":[7],"emissions":[8,59,166],"is":[9],"essential":[10],"for":[11,60,243],"tracking":[12],"climate":[13],"mitigation,":[14],"yet":[15],"natural":[16],"carbon-cycle":[17],"fluxes":[18],"often":[19],"obscure":[20],"human-induced":[21],"signals":[22],"in":[23,99,109,127,170,189,195],"atmospheric":[24,78],"observations.":[25],"This":[26,218],"study":[27,219],"presents":[28],"a":[29,83,106,115,240],"satellite-driven":[30],"data":[31,103,203,225],"assimilation":[32,226],"framework":[33],"that":[34,132,158],"uses":[35],"nitrogen":[36],"oxides":[37],"(NOx":[38],"=":[39],"NO":[40],"+":[41],"NO2)":[42],"\u2212":[43,50],"short-lived":[44],"trace":[45],"gases":[46],"co-emitted":[47],"with":[48,114,130,182],"to":[51,97,105,134,230],"estimate":[52,56],"ffCO2":[53,156,165,237],"emissions.":[54],"We":[55,81],"European":[57,236],"NOx":[58,89,151],"2021":[61],"by":[62,206],"assimilating":[63],"TROPOMI":[64],"NO2":[65],"observations":[66,131],"into":[67,154],"an":[68,124,135],"Ensemble":[69],"Kalman":[70],"Filter":[71],"(EnKF)":[72],"framework,":[73],"optimised":[74],"within":[75],"the":[76,110,214,221],"GEOS-Chem":[77],"transport":[79],"model.":[80],"use":[82],"computationally":[84],"efficient":[85],"offline":[86],"treatment":[87],"chemistry,":[90],"enabling":[91],"large-ensemble":[92],"inversions":[93],"while":[94],"retaining":[95],"sensitivity":[96],"changes":[98],"photochemistry.":[100],"Assimilating":[101],"these":[102],"leads":[104],"systematic":[107],"reduction":[108,119],"state":[111],"vector":[112],"uncertainty,":[113],"mean":[116,196],"ensemble-based":[117],"error":[118,197],"4.2\u20135.7":[121],"%,":[122],"and":[123,172,180,227],"overall":[125],"improvement":[126],"model":[128],"agreement":[129],"corresponds":[133],"annual":[136],"correlation":[137],"increase,":[138],"\u2206r":[139],"=0.12.":[140],"By":[141],"leveraging":[142],"sector-specific":[143],"NOx:CO2":[144],"emission":[145],"ratios,":[146],"we":[147],"translate":[148],"our":[149,209],"posterior":[150],"flux":[152],"estimates":[153,157],"improved":[155],"capture":[159],"enhanced":[160],"seasonal":[161],"variability.":[162,185],"Our":[163],"inferred":[164],"exhibit":[167],"elevated":[168],"values":[169],"autumn":[171],"winter,":[173],"spatially":[174],"concentrated":[175],"over":[176],"major":[177],"source":[178],"regions":[179],"consistent":[181,233],"surface":[183],"temperature":[184],"Independent":[186],"evaluation":[187],"against":[188],"situ":[190],"measurements":[191],"confirms":[192],"significant":[193],"improvements":[194],"statistics.":[198],"While":[199],"OCO-2":[200],"column":[202],"remain":[204],"dominated":[205],"biogenic":[207],"signals,":[208],"NO2-driven":[210],"approach":[211],"successfully":[212],"isolates":[213],"component.":[217],"demonstrates":[220],"potential":[222],"ensemble":[224],"reduced-complexity":[228],"chemistry":[229],"provide":[231],"physically":[232],"constraints":[234],"on":[235],"estimates,":[238],"establishing":[239],"vital":[241],"foundation":[242],"future":[244],"joint":[245],"NO2\u2013CO2":[246],"inversion":[247],"systems.":[248]},"counts_by_year":[],"updated_date":"2026-11-09T13:22:03.289127","created_date":"2026-10-02T00:00:00"}
