{
  "source": {
    "title": "Analysis of Carbon Dioxide in Air",
    "institution": "NOAA Global Monitoring Laboratory",
    "url": "https://gml.noaa.gov/ccl/docs/TP_analysis_CO2_v2.1.pdf#page=9",
    "version": "2.1",
    "effective_date": "2021-04-15",
    "signature_date": "2024-05-24",
    "accessed": "2026-10-19",
    "verified": "2026-11-06",
    "location": "Table A1, section 10.2, page 9 of 9",
    "pdf_sha256": "d03a86a1667a1a83b01fb9221f9c7ed5e5814f9347c02a709d166e6ef27dfab1"
  },
  "licence": {
    "name": "Public Domain, NOAA GML attribution",
    "url": "https://gml.noaa.gov/about/disclaimer.html"
  },
  "table": {
    "file": "noaa-table-a1.csv",
    "sha256_lf": "ec130033c9c7cade4864672e23c52bffec2b4558042fc332bdddfa6799cda8df",
    "measurement_date": "2017-01-24",
    "rows": 16,
    "sample_count": 8,
    "selection": "All rows printed in Table A1. No rows excluded or filled in.",
    "signal_meaning": "Instrument response Sig in the source, not raw light intensity. Signal units are not specified in Table A1.",
    "signal_sd_meaning": "Printed Sig_sd, standard deviation of N instrument readings.",
    "n_meaning": "Number of readings used for each printed signal mean.",
    "flag_meaning": "Original printed quality marker, a dot on all rows.",
    "ratio_meaning": "Sample response divided by mean of bracketing reference responses.",
    "x626_meaning": "Dry-air mole fraction of 16O12C16O, NOT total CO2, in micromol/mol (ppm).",
    "missing_data": "Reference after last SMP at 12:21:16 is not printed. Its ratio is used as published, not reconstructed.",
    "rounding": "Published signals have four decimals. Reconstructed ratios may differ from printed ratios due to rounding. Calibration uses the published ratios."
  },
  "calibration": {
    "equation": "x626 = c0 + c1 * r",
    "c0_ppm": 0.18436648,
    "c1_ppm": 395.56334783,
    "scope": "Coefficients printed for this 2017 episode only. The table does not explicitly state the scale version for this episode. Do not relabel these values as X2019."
  },
  "result": {
    "x626_ppm_from_published_ratios": [
      386.7273055264353,
      386.7321871737109,
      386.726551187131,
      386.72572050410054,
      386.7328738716827,
      386.7255148111597,
      386.7257568959286,
      386.72975129461497
    ],
    "mean_x626_ppm": 386.72820765809547,
    "sample_sd_x626_ppm": 0.002999862851159275,
    "published_mean_x626_ppm": 386.728,
    "published_sd_x626_ppm": 0.003,
    "mean_published_ratio": 0.977198325625
  }
}