# header_lines : 165
#
# ------------------------------------------------------------->>>>
# DATA SET NAME
#
# dataset_name: co2_mlo_surface-insitu_1_ccgg_HourlyData
#
# ------------------------------------------------------------->>>>
# DESCRIPTION
#
# dataset_description: Atmospheric Carbon Dioxide Dry Air Mole Fractions from quasi-continuous measurements at Mauna Loa, Hawaii.
#
# ------------------------------------------------------------->>>>
# CITATION
#
# dataset_citation: G. Pétron, P. Handley, J. Hakala, J. Kofler, K. W. Thoning, A. Crotwell, A. Clarke, J. Fernandez, I. Crocker, R. Burgener, B. Thomas, A. Colton, S. Jordan, L. Longren, M. Doneghey, M. Trudeau, T. Mefford, S. DeVogel, A. Searle, X. Lan, J. Mauss, C. Smith, B. Vasel, S. Morris, J. Miller and J. Mund (2026), Atmospheric Carbon Dioxide Dry Air Mole Fractions from continuous measurements at Mauna Loa, Hawaii, Utqiaġvik, Alaska, American Samoa and South Pole, 1973-present. Version 2026-06-04, National Oceanic and Atmospheric Administration (NOAA), Global Monitoring Laboratory (GML), Boulder, Colorado, USA https://doi.org/10.15138/yaf1-bk21
#
# ------------------------------------------------------------->>>>
# FAIR USE POLICY
#
# dataset_fair_use: These data are made freely available to the public and the scientific community in the belief that their wide dissemination will lead to greater understanding and new scientific insights. To ensure that GML receives fair credit for their work please include relevant citation text in publications. We encourage users to contact the data providers, who can provide detailed information about the measurements and scientific insight.  In cases where the data are central to a publication, coauthorship for data providers may be appropriate. 
#
# ------------------------------------------------------------->>>>
# WARNING
#
# dataset_warning: Every effort is made to produce the most accurate and precise measurements possible.  However, we reserve the right to make corrections to the data based on recalibration of standard gases or for other reasons deemed scientifically justified.  We are not responsible for results and conclusions based on use of these data without regard to this warning.
#
# ------------------------------------------------------------->>>>
# GLOBAL ATTRIBUTES
#
# site_code : MLO
# site_name : Mauna Loa, Hawaii
# site_country : United States
# site_country_flag : https://gml.noaa.gov/webdata/ccgg/ObsPack/images/flags/UNST0001.GIF
# site_latitude : 19.5362
# site_longitude : -155.5763
# site_elevation : 3397.0
# site_elevation_unit : masl
# site_position_comment : This is the nominal location of the site. The sampling location at many sites has changed over time, and we report here the most recent nominal location. The actual sampling location for each observation is not necessarily the site location. The sampling locations for each observation are reported in the latitude, longitude, and altitude variables.
# site_utc2lst : -10.0
# site_utc2lst_comment : Add 'site_utc2lst' hours to convert a time stamp in UTC (Coordinated Universal Time) to LST (Local Standard Time).
# site_url : https://gml.noaa.gov/obop/mlo/
# dataset_creation_date : 2026-06-04T09:29:19.244446
# dataset_num : 7
# dataset_name : co2_mlo_surface-insitu_1_ccgg_HourlyData
# dataset_parameter : co2
# dataset_parameter_name : Carbon Dioxide
# dataset_parameter_industrial_name : Carbon Dioxide
# dataset_project : surface-insitu
# dataset_platform : fixed
# dataset_selection : All hourly data
# dataset_selection_tag : HourlyData
# dataset_comment : For more information about these data, please see https://gml.noaa.gov/aftp/data/trace_gases/co2/in-situ/surface/README_co2_surface-insitu_ccgg.html
# dataset_calibration_scale : CO2_X2019
# dataset_start_date : 1974-05-01T00:00:00Z
# dataset_stop_date : 2025-12-31T23:00:00Z
# dataset_data_frequency : 1
# dataset_data_frequency_unit : hour
# dataset_usage_description : Please cite the product's citation when using data from this dataset. Relevant literature references for this dataset are listed below for convenience.
# dataset_provider_license : These data were produced by NOAA and are not subject to copyright protection in the United States. NOAA waives any potential copyright and related rights in these data worldwide through the Creative Commons Zero 1.0 Universal Public Domain Dedication (CC0-1.0).
# dataset_reference_total_listed : 3
# dataset_reference_1_name : Thoning, K.W., P.P. Tans, and W.D. Komhyr, Atmospheric carbon dioxide at Mauna Loa Observatory, 2. Analysis of the NOAA/GMCC data, 1974 1985., J. Geophys. Res. ,94, 8549 8565, 1989
# dataset_reference_2_name : Thoning, K.W. Selection of NOAA/GMCC CO2 data from Mauna Loa Observatory, In The Statistical Treatment of CO2 Data Records, NOAA Tech. Mem. (ERL ARL 173), Environ. Res. Lab., 131 pp., 1989
# dataset_reference_3_name : Komhyr, W.D., T.B. Harris, L.S. Waterman, J.F.S. Chin, and K.W. Thoning, Atmospheric carbon dioxide at Mauna Loa Observatory: 1. NOAA Global Monitoring for Climatic Change measurements with a nondispersive infrared analyzer, 1974 1985, J. Geophys. Res., 94, 8533 8547, 1989.
# dataset_contribution : These data are provided by NOAA. Principal investigators include Gabrielle Petron (NOAA) AND Philip Handley (NOAA).
# lab_total_listed : 1
# lab_1_number : 1
# lab_1_abbr : NOAA
# lab_1_name : NOAA Global Monitoring Laboratory
# lab_1_address1 : 325 Broadway
# lab_1_address2 : NOAA R/GML-1
# lab_1_address3 : Boulder, CO 80305-3328
# lab_1_country : United States
# lab_1_url : https://gml.noaa.gov/ccgg/
# lab_1_parameter : Lab has contributed measurements for: co2
# lab_1_country_flag : https://gml.noaa.gov/webdata/ccgg/ObsPack/images/flags/UNST0001.GIF
# lab_1_logo : https://gml.noaa.gov/webdata/ccgg/ObsPack/images/logos/noaa_medium.png
# lab_1_ongoing_atmospheric_air_comparison : T
# lab_1_comparison_activity : Ongoing comparison with co-located measurements including NOAA surface flask data and independent measurement laboratories.
# provider_total_listed : 2
# provider_1_name : Gabrielle Petron
# provider_1_address1 : NOAA GML
# provider_1_address2 : 325 Broadway R/GML-1
# provider_1_address3 : Boulder, CO 80305-3328
# provider_1_country : United  States
# provider_1_affiliation : CIRES, University of Colorado Boulder
# provider_1_email : Gabrielle.Petron@noaa.gov
# provider_1_tel : (720) 295-0145
# provider_1_parameter : Provider has contributed measurements for: co2
# provider_2_name : Philip Handley
# provider_2_address1 : NOAA GML
# provider_2_address2 : 325 Broadway R/GML-1
# provider_2_address3 : Boulder, CO 80305-3328
# provider_2_country : United States
# provider_2_affiliation : CIRES, University of Colorado Boulder
# provider_2_email : philip.handley@noaa.gov
# provider_2_parameter : Provider has contributed measurements for: co2
# ------------------------------------------------------------->>>>
# VARIABLE ATTRIBUTES
#
# site_code:long_name : site_name_abbreviation.
# site_code:comment : Site code is an abbreviation for the sampling site name.
# time_components:_FillValue : -9
# time_components:long_name : integer_components_of_UTC_date/time
# time_components:order : year, month, day, hour, minute, second
# time_components:comment : Calendar time components as integers. Times and dates are UTC. Time-averaged values are reported at the start of the averaging interval.
# datetime:long_name : air_sample_date_and_time_in_UTC
# datetime:comment : Air sample date and time in UTC ISO 8601 format. Time-averaged values are reported at the start of the averaging interval.
# time_decimal:_FillValue : -999.999
# time_decimal:long_name : sample_decimal_year_in_UTC
# time_decimal:comment : decimal year in UTC. Time-averaged values are reported at the start of the averaging interval.
# midpoint_time:long_name : sample_midpoint_time_in_seconds_since_january_1_1970
# midpoint_time:units : seconds since 1970-01-01T00:00:00Z
# midpoint_time:comment : POSIX midpoint time.  Number of seconds since January 1, 1970 in UTC.
# value:_FillValue : -999.999
# value:long_name : measured_mole_fraction_of_trace_gas_in_dry_air
# value:units : micromol mol-1
# value:comment : Mole fraction reported in units of micromol mol-1 (10-6 mol per mol of dry air); abbreviated as ppm (parts per million).
# value:scale_comment : CO2_X2019
# value_std_dev:_FillValue : -99.99
# value_std_dev:long_name : standard_deviation_in_reported_value
# value_std_dev:units : micromol mol-1
# value_std_dev:comment : This is the standard deviation of the reported mean value when nvalue is greater than 1. See provider_comment if available.
# value_std_dev:provider_comment : value_std_dev can be defined when nvalue (number of measurements) = 1.  See accompanying README for details.
# value_unc:_FillValue : -999.999
# value_unc:long_name : estimated_uncertainty_in_reported_value
# value_unc:units : micromol mol-1
# value_unc:comment : This is the estimated uncertainty of the reported value. See provider_comment if available.
# nvalue:_FillValue : -9
# nvalue:long_name : number_of_measurements_contributing_to_reported_value
# nvalue:comment : Number of individual measurements used to compute reported value. See provider_comment if available.
# latitude:_FillValue : -999.999
# latitude:standard_name : latitude
# latitude:long_name : sample_latitude_in_decimal_degrees
# latitude:units : degrees_north
# latitude:comment : Latitude at which air sample was collected.
# longitude:_FillValue : -999.999
# longitude:standard_name : longitude
# longitude:long_name : sample_longitude_in_decimal_degrees
# longitude:units : degrees_east
# longitude:comment : Longitude at which air sample was collected using a range of -180 degrees to +180 degrees.
# altitude:_FillValue : -999.999
# altitude:standard_name : altitude
# altitude:long_name : sample_altitude_in_meters_above_sea_level
# altitude:units : m
# altitude:comment : Altitude (in meters above sea level). See provider_comment if available.
# altitude:provider_comment : Altitude for this dataset is the sum of surface elevation (masl) and sample intake height (magl).
# elevation:_FillValue : -999.999
# elevation:standard_name : elevation
# elevation:long_name : surface_elevation_in_meters_above_sea_level
# elevation:units : m
# elevation:comment : Surface elevation in meters above sea level. See provider_comment if available.
# intake_height:_FillValue : -999.999
# intake_height:long_name : sample_intake_height_in_meters_above_ground_level
# intake_height:units : m
# intake_height:comment : Sample intake height in meters above ground level (magl). See provider_comment if available.
# instrument:long_name : instrument_ID_to_detect_atmospheric_parameter
# instrument:comment : Instrument ID used to detect atmospheric parameter. See provider_comment if available.
# qcflag:long_name : quality_control_flag
# qcflag:comment : This quality control flag is provided by the contributing PIs. See provider_comment if available.
# qcflag:provider_comment : This is the NOAA 3-character quality control flag.  Column 1 is the REJECTION flag. An alphanumeric other than a period (.) in the FIRST column indicates a sample with obvious problems during collection or analysis. This measurement should not be interpreted. Column 2 is the SELECTION flag. An alphanumeric other than a period (.) in the SECOND column indicates a sample that is likely valid but does not meet selection criteria determined by the goals of a particular investigation. Column 3 is the INFORMATION flag. An alphanumeric other than a period (.) in the THIRD column provides additional information about the collection or analysis of the sample.
#
# VARIABLE ORDER
#
site_code year month day hour minute second datetime time_decimal midpoint_time value value_std_dev value_unc nvalue latitude longitude altitude elevation intake_height instrument qcflag
MLO 1974 5 1 0 0 0 1974-05-01T00:00:00Z 1974.3287671232877 136600200 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 1 0 0 1974-05-01T01:00:00Z 1974.3288812785388 136603800 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 2 0 0 1974-05-01T02:00:00Z 1974.32899543379 136607400 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 3 0 0 1974-05-01T03:00:00Z 1974.329109589041 136611000 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 4 0 0 1974-05-01T04:00:00Z 1974.3292237442922 136614600 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 5 0 0 1974-05-01T05:00:00Z 1974.3293378995434 136618200 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 6 0 0 1974-05-01T06:00:00Z 1974.3294520547945 136621800 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 7 0 0 1974-05-01T07:00:00Z 1974.3295662100456 136625400 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 8 0 0 1974-05-01T08:00:00Z 1974.3296803652968 136629000 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 9 0 0 1974-05-01T09:00:00Z 1974.329794520548 136632600 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 10 0 0 1974-05-01T10:00:00Z 1974.329908675799 136636200 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 11 0 0 1974-05-01T11:00:00Z 1974.3300228310502 136639800 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 12 0 0 1974-05-01T12:00:00Z 1974.3301369863013 136643400 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 13 0 0 1974-05-01T13:00:00Z 1974.3302511415525 136647000 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 14 0 0 1974-05-01T14:00:00Z 1974.3303652968036 136650600 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 15 0 0 1974-05-01T15:00:00Z 1974.3304794520548 136654200 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 16 0 0 1974-05-01T16:00:00Z 1974.330593607306 136657800 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 17 0 0 1974-05-01T17:00:00Z 1974.330707762557 136661400 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 18 0 0 1974-05-01T18:00:00Z 1974.3308219178082 136665000 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
MLO 1974 5 1 19 0 0 1974-05-01T19:00:00Z 1974.3309360730593 136668600 -999.99 nan nan 0 19.536 -155.576 3422.0 3397.0 25.0 UR1-1 *..
