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    • ACT-America: L1 Raw, Uncalibrated In-Situ CO2, CO, and CH4 Mole Fractions from Towers

    Metadata Updated: October 30, 2025

    This dataset provides Level 1 (L1) in situ atmospheric carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4) concentrations as measured on a network of instrumented communications towers across the central and eastern USA operated by the Atmospheric Carbon and Transport-America (ACT-America) project. There were 11 towers instrumented with cavity ring-down spectrometers (CRDS; Picarro Inc.) with measurements beginning in January 2015 and continuing to October 2019. The measurement period varied by tower site. The Picarro analyzers continuously measured total CH4, isotopic ratio of CH4, CO2, CO, and other greenhouse gas concentrations. Not all species were measured at all sites. Complete tower location, elevation, instrument height, and date/time information are also provided. Determination of greenhouse gas fluxes and uncertainty bounds is essential for the evaluation of the effectiveness of mitigation strategies. These L1 data are raw instrument outputs from the Picarro instruments. A Level 2 (L2) product derived from this L1 data is available and generally would be the preferred data for most use cases.

    Access & Use Information

    Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Created Date April 11, 2025
    Metadata Updated Date October 30, 2025

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date April 11, 2025
    Metadata Updated Date October 30, 2025
    Publisher ORNL_DAAC
    Maintainer
    Identifier 10.3334/ORNLDAAC/1798
    Data Last Modified 2025-09-10
    Category Earth Science
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Harvest Object Id 2cb29285-9e96-4a51-b9b1-1a4055db23e3
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://search.earthdata.nasa.gov/search?q=Insitu_Tower_Greenhouse_Gas_1798&ac=true
    Old Spatial {"WestBoundingCoordinate":-98.588,"NorthBoundingCoordinate":44.0502,"EastBoundingCoordinate":-76.4188,"SouthBoundingCoordinate":30.1951},"CARTESIAN"
    Program Code 026:000
    Source Datajson Identifier True
    Source Hash 68c0cb2f8064de76510a187599c3d7bd63f4008fc16f1be945bc755410d19512
    Source Schema Version 1.1
    Spatial
    Temporal 2015-01-01/2015-01-01

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