{
  "abstract": "We evaluated daily paired Community Multiscale Air Quality (CMAQ) estimates and observations during California fire seasons (June–October), 2008–2018, using conventional metrics, classifications at 12 and 35 µg m⁻³, two case studies, and a leakage-resistant Random Forest diagnostic. After quarantining 18 CMAQ total PM₂.₅ values above 557 µg m⁻³ without capping, the primary analysis contained 187,051 records. Observed and modeled means were 10.69 and 9.29 µg m⁻³; Pearson r was 0.502 (r² = 0.252), mean bias was − 1.40 µg m⁻³, and RMSE was 9.96 µg m⁻³. CMAQ detected 45.4% of observed events at the descriptive/former annual level of 12 µg m⁻³ and 40.8% at the current 35 µg m⁻³ 24-hour standard level. At 35 µg m⁻³, CMAQ produced more events overall but missed 1,273 of 2,151 observed events because modeled and observed events often did not coincide by site-day. The Random Forest excluded observed PM₂.₅, CMAQ total PM₂.₅, and the no-fire component from its primary features. In an untouched site-year test partition (n = 37,430), R² was 0.711, RMSE was 5.82 µg m⁻³, and MAE was 3.44 µg m⁻³; fire-only CMAQ PM₂.₅ was the dominant predictor. CMAQ remains useful for regional and multi-year analyses, but paired-event detection and localized extreme-smoke estimates require explicit uncertainty treatment.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 16,
  "authors": [
    {
      "name": "Eimy X. Bonilla"
    },
    {
      "name": "Jose Perez-Chavez"
    },
    {
      "name": "Daja Elum"
    },
    {
      "name": "Olutoyosi Oyelowo"
    },
    {
      "name": "Samuel Kane"
    },
    {
      "name": "Rachel E. Connolly"
    },
    {
      "name": "Miriam E. Marlier"
    },
    {
      "name": "Jihoon Jung"
    },
    {
      "name": "Mohammad Al-Hamdan"
    },
    {
      "name": "Claire L. Schollaert"
    },
    {
      "name": "John C. Flunker"
    },
    {
      "name": "Huikyo Lee"
    },
    {
      "name": "Sambit Bhattacharya"
    },
    {
      "name": "Osinachi Ajoku"
    },
    {
      "name": "Christopher Blaszczak-Boxe"
    },
    {
      "name": "Joseph L. Wilkins"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/69a5mmkk6bxf8.bib",
  "cited_by": 0,
  "doi": "10.21203/rs.3.rs-11167409/v1",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13734238/",
  "id": "69a5mmkk6bxf8",
  "issns": [
    "2693-5015"
  ],
  "landing_url": "https://doi.org/10.21203/rs.3.rs-11167409/v1",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Article"
    ],
    [
      "openalex",
      "1902|Atmospheric chemistry and aerosols"
    ]
  ],
  "openalex": "W7225045261",
  "pdf_url": "https://www.researchsquare.com/article/rs-11167409/latest.pdf",
  "pmcid": "PMC13734238",
  "pmid": "42990503",
  "published": "2026-11-01",
  "publisher": "American Journal Experts",
  "ris": "https://research.draconitic.com/paper/69a5mmkk6bxf8.ris",
  "sources": [
    {
      "first_seen": "2026-11-08T12:23:51Z",
      "native_id": "PMC13734238",
      "source": "pmc",
      "url": "https://doi.org/10.21203/rs.3.rs-11167409/v1"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "openalex:1902|Atmospheric chemistry and aerosols",
      "subfield": "atmospheric"
    }
  ],
  "title": "Evaluating CMAQ Representation of Wildfire PM₂.₅ in California (2008–2018): Regime-Dependent Performance and Nonlinear Error Structure",
  "title_text": "Evaluating CMAQ Representation of Wildfire PM₂.₅ in California (2008–2018): Regime-Dependent Performance and Nonlinear Error Structure",
  "type": "preprint",
  "updated_at": "2026-11-08T12:23:51Z",
  "url": "https://research.draconitic.com/paper/69a5mmkk6bxf8",
  "venue": "Research Square",
  "versions": []
}