{
  "manifest_version": 1,
  "recorded_at": "2026-09-07",
  "source_summary": "docs/validation.md",
  "evidence_status": "Published aggregate summary; historical runs have not been independently reproduced by this manifest",
  "runtime_artifact": {
    "path": "icon_uv/data/rt.npz",
    "sha256": "a33db2d4b2806f216eef356c761460383bb4a9fca53e3b958715bc12e6d6dcba"
  },
  "observational_campaign": {
    "period_start_month": "2024-08",
    "period_end_month": "2026-08",
    "initialization_dates": 150,
    "complete_forecast_site_days": 583,
    "member": "CTRL",
    "forecast_days": [1, 2],
    "uv_albedo": 0.05,
    "comparison": "Matching half-hour observation and prediction windows",
    "metric_definition": "MAE in unrounded UVI; display agreement uses half-up rounded integers",
    "sites": [
      {"name": "Davos", "complete_days": [146, 146], "daily_peak_mae_uvi": [0.61, 0.64], "within_one_displayed_unit_percent": [89, 88]},
      {"name": "Weissfluhjoch", "complete_days": [100, 99], "daily_peak_mae_uvi": [0.78, 0.85], "within_one_displayed_unit_percent": [86, 81]},
      {"name": "Payerne", "complete_days": [46, 46], "daily_peak_mae_uvi": [0.48, 0.50], "within_one_displayed_unit_percent": [98, 94]}
    ],
    "rolling_peak_comparison": {
      "site": "Payerne",
      "window_minutes": 30,
      "approximate_mae_uvi_by_forecast_day": [0.52, 0.52]
    }
  },
  "cloud_conversion_assessment": {
    "site": "Payerne",
    "input": "Colocated measured shortwave radiation",
    "subset": "290 cloudy hours on 57 summer/autumn days within the observational campaign",
    "selection": {"shortwave_fraction_of_clear_sky_below": 0.8, "maximum_solar_zenith_degrees": 70, "minimum_clear_sky_uvi": 1},
    "uv_albedo": 0.05,
    "mae_uvi": 0.11,
    "mean_error_uvi": 0.07
  },
  "numerical_assessment": {
    "reference": "Direct libRadtran calculations",
    "withheld_atmospheric_states": 80,
    "minimum_reference_uvi": 1,
    "forward_uv_relative_error_p95_percent": 2.8,
    "shortwave_to_uv_relative_error_p95_upper_percent": 1.7,
    "interpretation": "Numerical accuracy within the selected solver physics"
  },
  "sensitivity_assessment": {
    "cases": 150,
    "varied": ["cloud height", "droplet size", "cloud phase", "surface reflectivity"],
    "liquid_cloud_dark_surface_max_difference_uvi": 0.14,
    "unresolved_clear_cloud_mixture_approximate_difference_uvi": 0.5,
    "high_ice_cloud_bright_snow_tested_difference_uvi": 1.3,
    "interpretation": "Scenario sensitivities, not general error bounds"
  },
  "not_established_by_this_evidence": [
    "Production snow-dependent UV albedo accuracy",
    "Regional altitude-band aggregate accuracy",
    "Calibrated ensemble spread or ensemble observational skill",
    "General error bounds for extreme UV or cloud enhancement"
  ],
  "coverage_gaps": [
    "Payerne January–June 2025 excluded because instrument identity was missing",
    "Much of Weissfluhjoch 2026 unavailable",
    "Accessible corrected UV unavailable for the identified Jungfraujoch and Locarno-Monti sites",
    "Historical production snow fraction unavailable"
  ],
  "reproduction_inputs": {
    "status": "Not provided in the public repository",
    "historical_code_revision": null,
    "campaign_configuration": null,
    "initialization_date_list": null,
    "observation_and_forecast_input_hashes": null,
    "paired_sample_outputs": null,
    "solver_executable_and_reference_cache_hashes": null,
    "archived_run_artifact_url": null,
    "needed_to_reproduce": "Archive the exact campaign code/configuration, input identities, selection masks and paired outputs with permitted access; link those artifacts here. Null means unavailable, never a verified empty input."
  }
}