Tight physics and chemistry coupling improves air quality forecasts: a case study of the 2020 North American wildfires with the Rapid Refresh model coupled to Chemistry (RAP-Chem v1.0)
Rattachement africain : us, br. Niveau de preuve : code pays fourni par la source.
Le résumé fourni par la source
Abstract. The Rapid Refresh model coupled to Chemistry (RAP-Chem) is an experimental forecast model built and operated by the NOAA Global Systems Laboratory (GSL). The RAP-Chem is a full chemistry extension to the operational smoke forecasting model, RAP-Smoke. RAP-Chem’s chemistry includes a reduced complexity, carbon-bond, gas-phase mechanism and an aerosol scheme that are coupled together to produce secondary aerosols and perform heterogeneous chemistry. The model includes chemical lateral boundary conditions, hourly anthropogenic emissions and online emissions from biomass burning, dust, sea salt, and biogenic sources. RAP-Chem also includes the direct aerosol effect on radiation and photolysis and a simplified indirect aerosol effect that couples prognostic aerosols to representative aerosols in the aerosol-aware microphysics scheme. The default ‘offline’ vertical mixing implemented in WRF-Chem is updated to instead mix chemical species alongside other scalars in the model’s planetary boundary layer (PBL) scheme, which tends to improve predictions across species – increasing surface ozone (O3) and decreasing less reactive tracers (e.g., CO). Sub-grid boundary layer clouds in the PBL scheme are also coupled to a WRF-Chem photolysis scheme for the first time, overall reducing O3 biases in the eastern US. Here we present the ability of the RAP-Chem model to simulate the extreme North American wildfires in 2020. We demonstrate that the relatively simple gas-phase chemical mechanism alongside our model physics developments and coupling with chemistry can predict maximum daily 8-h average O3 with exceptional skill (Normalized Mean Bias (NMB) = 6.6 %) averaged over CONUS, improving on simulations that neglect the direct aerosol effect (NMB = 9.5 %). Ozone biases are large in regions with extreme aerosol loading, but the NMB improves more significantly. The model produces the observed extreme aerosol loading with less skill; tending to underpredict extreme wildfire induced concentrations while overpredicting urban particle pollution. As with O3, daily average PM2.5 is predicted with better skill when the direct aerosol feedback is included (-15.8 % vs. -16.8 %). Overall we find that improving the coupling between chemistry and physics processes in the air quality model improves its predictions of both weather and atmospheric composition.
Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.
Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Tight physics and chemistry coupling improves air quality forecasts: a case study of the 2020 North American wildfires with the Rapid Refresh model coupled to Chemistry (RAP-Chem v1.0)
- Date Crossref
- 13/08/2026
- Éditeur
- Copernicus GmbH
- Type
- posted-content
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
-
National Oceanic and Atmospheric Administration pays non établi dans la noticeOrganisme public
-
Cooperative Institute for Research in Environmental Sciences pays non établi dans la noticeStructure de recherche
-
NOAA Earth System Research Laboratory pays non établi dans la noticeOrganisme public
-
NOAA Chemical Sciences Laboratory pays non établi dans la noticeOrganisme public
-
University of Colorado Boulder Cooperative Institute for Research in Environmental Sciences (CIRES) pays non établi dans la noticeUniversité ou école supérieure
-
University of Wisconsin–Madison pays non établi dans la noticeUniversité ou école supérieure
-
NOAA Air Resources Laboratory pays non établi dans la noticeOrganisme public
-
Instituto Nacional de Pesquisas Espaciais pays non établi dans la noticeStructure de recherche
-
Federal University of São João del-Rei pays non établi dans la noticeUniversité ou école supérieure
-
NOAA National Environmental Satellite Data and Information Service pays non établi dans la noticeOrganisme public
-
NOAA Global Systems Laboratory (Boulder pays non établi dans la noticeStructure de recherche
-
Colorado State University Cooperative Institute for Research in the Atmosphere (CIRA) pays non établi dans la noticeUniversité ou école supérieure
National Oceanic and Atmospheric Administration, Cooperative Institute for Research in Environmental Sciences et NOAA Earth System Research Laboratory, avec 9 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.