{
  "schema_version": "2.0.0",
  "dataset_id": "hv-nz-track-air-density-v1",
  "data_updated_at": "2026-10-30T18:30:02Z",
  "method_reviewed_at": "2026-10-30",
  "page_modified_at": "2026-10-30",
  "formula_standard": "ICAO / ISA Standard Atmosphere (1.2250 kg/m³ at 15°C, 1013.25 hPa dry) + Tetens Water Vapor Partial Pressure Compensation",
  "update_cadence": "Every 30 minutes via systemd/cron daemon from Open-Meteo Forecast API",
  "active_tracks_count": 6,
  "active_tracks": [
    {
      "id": "hampton-downs",
      "name": "Hampton Downs Motorsport Park",
      "short_name": "Hampton Downs",
      "region": "North Waikato, NZ",
      "lat": -37.3536,
      "lon": 175.0758,
      "elev_m": 55,
      "length_km": 3.8,
      "status": "Active · FIA Grade 3",
      "ecu_notes": "Fast front straight with elevation climb; monitor MAP/MAT delta under sustained high-load WOT.",
      "observed_at_nzt": "2026-10-31T07:30",
      "temp_c": 12.9,
      "dew_point_c": 6.9,
      "rh_pct": 67,
      "surface_pressure_hpa": 1019.3,
      "surface_pressure_kpa": 101.93,
      "pressure_msl_hpa": 1019.8,
      "vapor_pressure_hpa": 9.97,
      "air_density_kg_m3": 1.2368,
      "rad_pct": 100.96,
      "density_altitude_m": -100,
      "density_altitude_ft": -328,
      "air_mass_delta_pct": 0.96,
      "wind_kmh": 13.9,
      "wind_dir_deg": 193
    },
    {
      "id": "taupo",
      "name": "Taupō International Motorsport Park",
      "short_name": "Taupō Motorsport Park",
      "region": "Taupō, Central Plateau, NZ",
      "lat": -38.665,
      "lon": 176.1436,
      "elev_m": 408,
      "length_km": 3.32,
      "status": "Active · FIA Grade 2 (Supercars)",
      "ecu_notes": "Highest elevation circuit in NZ (408m ASL); ambient barometric pressure sits ~45–48 hPa below sea-level ISA.",
      "observed_at_nzt": "2026-10-31T07:30",
      "temp_c": 6.1,
      "dew_point_c": 1.8,
      "rh_pct": 74,
      "surface_pressure_hpa": 964.4,
      "surface_pressure_kpa": 96.44,
      "pressure_msl_hpa": 1019.3,
      "vapor_pressure_hpa": 6.97,
      "air_density_kg_m3": 1.1998,
      "rad_pct": 97.94,
      "density_altitude_m": 216,
      "density_altitude_ft": 709,
      "air_mass_delta_pct": -2.06,
      "wind_kmh": 3.1,
      "wind_dir_deg": 167
    },
    {
      "id": "manfeild",
      "name": "Manfeild Circuit Chris Amon",
      "short_name": "Manfeild Circuit",
      "region": "Feilding, Manawatū, NZ",
      "lat": -40.2378,
      "lon": 175.5572,
      "elev_m": 72,
      "length_km": 3.03,
      "status": "Active · National Championship",
      "ecu_notes": "High-humidity Manawatū plains; verify Baro/MAP compensation and intercooler heat-soak recovery.",
      "observed_at_nzt": "2026-10-31T07:30",
      "temp_c": 8.3,
      "dew_point_c": 5.4,
      "rh_pct": 82,
      "surface_pressure_hpa": 1012.2,
      "surface_pressure_kpa": 101.22,
      "pressure_msl_hpa": 1019.3,
      "vapor_pressure_hpa": 8.98,
      "air_density_kg_m3": 1.2486,
      "rad_pct": 101.93,
      "density_altitude_m": -200,
      "density_altitude_ft": -656,
      "air_mass_delta_pct": 1.93,
      "wind_kmh": 3.4,
      "wind_dir_deg": 252
    },
    {
      "id": "ruapuna",
      "name": "Euromarque Motorsport Park (Ruapuna)",
      "short_name": "Ruapuna Park",
      "region": "Christchurch, Canterbury, NZ",
      "lat": -43.5314,
      "lon": 172.4792,
      "elev_m": 42,
      "length_km": 3.33,
      "status": "Active · FIA Grade 3",
      "ecu_notes": "Subject to rapid Canterbury Nor'wester foehn wind temperature spikes (+10°C within 2 hours) affecting MAT fuel trim.",
      "observed_at_nzt": "2026-10-31T07:30",
      "temp_c": 5.5,
      "dew_point_c": 2.0,
      "rh_pct": 78,
      "surface_pressure_hpa": 1014.0,
      "surface_pressure_kpa": 101.4,
      "pressure_msl_hpa": 1019.6,
      "vapor_pressure_hpa": 7.04,
      "air_density_kg_m3": 1.2643,
      "rad_pct": 103.21,
      "density_altitude_m": -331,
      "density_altitude_ft": -1086,
      "air_mass_delta_pct": 3.21,
      "wind_kmh": 13.8,
      "wind_dir_deg": 244
    },
    {
      "id": "highlands",
      "name": "Highlands Motorsport Park",
      "short_name": "Highlands Cromwell",
      "region": "Cromwell, Central Otago, NZ",
      "lat": -45.0489,
      "lon": 169.1678,
      "elev_m": 218,
      "length_km": 4.1,
      "status": "Active · FIA Grade 3",
      "ecu_notes": "Alpine dry continental climate (218m ASL); wide diurnal air-density swings between morning qualifying and afternoon race.",
      "observed_at_nzt": "2026-10-31T07:30",
      "temp_c": 4.7,
      "dew_point_c": 0.3,
      "rh_pct": 73,
      "surface_pressure_hpa": 992.8,
      "surface_pressure_kpa": 99.28,
      "pressure_msl_hpa": 1020.6,
      "vapor_pressure_hpa": 6.24,
      "air_density_kg_m3": 1.2418,
      "rad_pct": 101.37,
      "density_altitude_m": -142,
      "density_altitude_ft": -466,
      "air_mass_delta_pct": 1.37,
      "wind_kmh": 7.2,
      "wind_dir_deg": 3
    },
    {
      "id": "teretonga",
      "name": "Teretonga Park",
      "short_name": "Teretonga Park",
      "region": "Invercargill, Southland, NZ",
      "lat": -46.4447,
      "lon": 168.2575,
      "elev_m": 6,
      "length_km": 2.57,
      "status": "Active · World's Southernmost FIA Circuit",
      "ecu_notes": "Cold, dense sea-level southern air often yields RAD > 101–103%; ensure injector duty cycle headroom on E85/Methanol.",
      "observed_at_nzt": "2026-10-31T07:30",
      "temp_c": 7.8,
      "dew_point_c": 1.0,
      "rh_pct": 62,
      "surface_pressure_hpa": 1018.6,
      "surface_pressure_kpa": 101.86,
      "pressure_msl_hpa": 1019.0,
      "vapor_pressure_hpa": 6.56,
      "air_density_kg_m3": 1.2599,
      "rad_pct": 102.85,
      "density_altitude_m": -294,
      "density_altitude_ft": -965,
      "air_mass_delta_pct": 2.85,
      "wind_kmh": 20.2,
      "wind_dir_deg": 262
    }
  ],
  "historical_tracks": [
    {
      "id": "pukekohe-archive",
      "name": "Pukekohe Park Raceway",
      "short_name": "Pukekohe (Closed 2023)",
      "region": "Pukekohe, South Auckland, NZ",
      "lat": -37.2189,
      "lon": 174.9197,
      "elev_m": 64,
      "length_km": 2.91,
      "status": "Historical Archive — Closed April 2023",
      "historical_baseline": {
        "isa_ref_pressure_hpa": 1005.6,
        "typical_rad_range_pct": "97.8% – 101.4%",
        "archive_note": "Motorsport operations at Pukekohe Park ceased in April 2023. Retained strictly as a historical reference baseline for comparing 2017–2023 Emtron/MoTeC datalogs."
      }
    }
  ],
  "jolpica_f1_next_event": {
    "season": "2026",
    "round": "19",
    "race_name": "Mexico City Grand Prix",
    "circuit_name": "Autódromo Hermanos Rodríguez",
    "locality": "Mexico City",
    "country": "Mexico",
    "date": "2026-11-01",
    "time_utc": "20:00:00Z",
    "source_api": "https://api.jolpi.ca/ergast/f1/current/next.json"
  },
  "open_source_can_releases": [
    {
      "repo": "collin80/SavvyCAN",
      "description": "Qt5/C++ cross-platform CAN-bus reverse engineering & DBC frame analyzer",
      "tag_name": "V220",
      "name": "V220",
      "published_at": "2025-05-09",
      "html_url": "https://github.com/collin80/SavvyCAN/releases/tag/V220"
    },
    {
      "repo": "hardbyte/python-can",
      "description": "Python Controller Area Network (SocketCAN, Kvaser, PEAK, Vector) interface library",
      "tag_name": "v4.6.1",
      "name": "4.6.1",
      "published_at": "2025-08-12",
      "html_url": "https://github.com/hardbyte/python-can/releases/tag/v4.6.1"
    },
    {
      "repo": "cantools/cantools",
      "description": "CAN bus DBC, KCD, SYM, ARXML and CDD frame encoding/decoding & C-code generator",
      "tag_name": "45.1.2",
      "name": "45.1.2",
      "published_at": "2026-10-29",
      "html_url": "https://github.com/cantools/cantools/releases/tag/45.1.2"
    }
  ]
}