Hourly observations of carbon dioxide (CO2) and methane (CH4) mole fractions in dry air from tower- and rooftop-based sites in the Los Angeles Megacity Carbon Project network. Carbon monoxide (CO) observations exist at several stations in this network but are not included in this data release pending additional calibration verification. Please contact the authors for higher frequency data, which are available on request. Data files are comma delimited (CSV). Measurements of each species may be from two or more different heights above ground. Site locations, heights, and other information are in a separate ASCII (CSV) file (LAM_sites.csv). Data are currently reported for the years 2015-2023. An ASCII Readme file (LAM_Readme_2024) is also posted. CO2 data are reported on the NOAA/WMO X2007 calibration scale. A full revision on the NOAA/WMO X2019 scale for CO2 is forthcoming, and will be linked here. CH4 data are reported on the NOAA/WMO X2004A calibration scale. Current update: May 17, 2024.

Updated April 2025. Here we provide hourly observations of carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) mole fractions in dry air from tower- and rooftop-based sites in the Los Angeles Megacity Carbon Project network. Each *.tgz (tar/gzip) archive contains data files for a given site location, named by its 3-letter code. To extract *.tgz files on a unix platform, use "tar -xvzf ". Data files with in the -1-hr-CSV.tgz archives are comma delimited (CSV) 1-hour averages; data files within the _1-hr-NC.tgz archives are 1-hour averages in NetCDF format; data files within the -1-min-CSV.tgz are CSV files with 1-minute averages (there is no NetCDF version for 1-minute data). Site locations, heights, and other information are in a separate ascii (CSV) file (LAM_sites.csv), and also within each data file (for the 1-hour averages files). We encourage the use of the locations within the hourly data files, as some locations may have changed during the site lifetime and have duplicate entries in the site file. Data in this archive is for January 1 2015-January 31 2025. ASCII Readme files (1Readme_v20250425.txt and 1Readme_1minfiles_v20250425.txt) contain data details; Updates_v20250425.pdf includes additional information on updates since the previous data version. Note about calibrations: CO2 data are reported on the NOAA/WMO X2019 calibration scale. CH4 data are reported on the NOAA/WMO X2004A calibration scale; CO data, where available, are reported on the NOAA/WMO X2014 scale. Note that previous archive s of this data reported CO2 on the X2007 scale. This data is being freely distributed for research, academic and related non-commercial purposes consistent with NIST's mandate to further the science and the promulgation of appropriate standards. Current update: April 25, 2025.

Updated April 2025. Here we provide hourly observations of carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) mole fractions in dry air from tower- and rooftop-based sites in the Los Angeles Megacity Carbon Project network. Each *.tgz (tar/gzip) archive contains data files for a given site location, named by its 3-letter code. To extract *.tgz files on a unix platform, use "tar -xvzf ". Data files with in the -1-hr-CSV.tgz archives are comma delimited (CSV) 1-hour averages; data files within the _1-hr-NC.tgz archives are 1-hour averages in NetCDF format; data files within the -1-min-CSV.tgz are CSV files with 1-minute averages (there is no NetCDF version for 1-minute data). Site locations, heights, and other information are in a separate ascii (CSV) file (LAM_sites.csv), and also within each data file (for the 1-hour averages files). We encourage the use of the locations within the hourly data files, as some locations may have changed during the site lifetime and have duplicate entries in the site file. Data in this archive is for January 1 2015-January 31 2025. ASCII Readme files (1Readme_v20250425.txt and 1Readme_1minfiles_v20250425.txt) contain data details; Updates_v20250425.pdf includes additional information on updates since the previous data version. Note about calibrations: CO2 data are reported on the NOAA/WMO X2019 calibration scale. CH4 data are reported on the NOAA/WMO X2004A calibration scale; CO data, where available, are reported on the NOAA/WMO X2014 scale. Note that previous archive s of this data reported CO2 on the X2007 scale. This data is being freely distributed for research, academic and related non-commercial purposes consistent with NIST's mandate to further the science and the promulgation of appropriate standards. Current update: April 25, 2025.

Data files in this repository contain a static archive of all the observational and model data required to construct fossil-fuel enhancements at tower sites in Los Angeles (LA_data.csv) and DC-Baltimore (DCBalt_data.csv). These were used in the analyses detailed and presented in the publication "The impact of COVID-19 on CO2 emissions in the Los Angeles and Washington DC/Baltimore metropolitan areas" by Yadav et al.

NOTE: please see the latest (March 2025) update at https://doi.org/10.18434/mds2-3765 . This archive is from May 2023. See Updates document for specific major and minor changes. Here we provide hourly observations of carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) from tower-based sites in the NIST Northeast Corridor network. Each *.tgz (tar/gzip) archive contains data files for a given site location, named by its 3-letter code (see NEC_sites.csv for codes and locations). To extract on a unix platform, use "tar -xvzf ". Data files within the .tgz archives are comma delimited (CSV); data files within the _NC.tgz archives are in NetCDF format. Site locations, heights, and other information are in a separate ascii (CSV) file (NEC_sites.csv), and also within each data file. Data in this archive is reported for the years 2015-2022. An ASCII Readme file (NEC_Readme_05052023) is also posted, along with an Updates_05052023.txt file that includes additional information on updates. Note about calibrations: CO2 data are reported on the NOAA/WMO X2007 calibration scale. CH4 data are reported on the NOAA/WMO X2004A calibration scale; CO data, where available, are reported on the NOAA/WMO X2014 scale. This archive, with CO2 data on the X2007 scale, will no longer be updated. A full revision of all the data on the NOAA/WMO X2019 scale for CO2 is forthcoming, and will be linked here; that archive will maintain its own record and DOI, include CH4 and CO, and will be continually updated. This data is being freely distributed for research, academic and related non-commercial purposes consistent with NIST's mandate to further the science and the promulgation of appropriate standards. Current update: May 5, 2023.

Note: This data archive supersedes our previous archive: https://doi.org/10.18434/mds2-2491. See Updates document for specific major and minor changes. Here we provide hourly observations of carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) from tower-based sites in the NIST Northeast Corridor network. Each *.tgz (tar/gzip) archive contains data files for a given site location, named by its 3-letter code (see NEC_sites.csv for codes and locations). To extract on a unix platform, use "tar -xvzf ". Data files within the .tgz archives are comma delimited (CSV); data files within the _NC.tgz archives are in NetCDF format. Site locations, heights, and other information are in a separate ascii (CSV) file (NEC_sites.csv), and also within each data file. Data in this archive is reported for the years 2015-2022. An ASCII Readme file (NEC_Readme_05052023) is also posted, along with an Updates_05052023.txt file that includes additional information on updates. Note about calibrations: CO2 data are reported on the NOAA/WMO X2007 calibration scale. CH4 data are reported on the NOAA/WMO X2004A calibration scale; CO data, where available, are reported on the NOAA/WMO X2014 scale. This archive, with CO2 data on the X2007 scale, will no longer be updated. A full revision of all the data on the NOAA/WMO X2019 scale for CO2 is forthcoming, and will be linked here; that archive will maintain its own record and DOI, include CH4 and CO, and will be continually updated. This data is being freely distributed for research, academic and related non-commercial purposes consistent with NIST's mandate to further the science and the promulgation of appropriate standards. Current update: May 5, 2023.

March 2025 Update. Here we provide hourly observations of atmospheric carbon dioxide (CO2), methane (CH4), and (for a few sites) carbon monoxide (CO) from tower-based sites in the NIST Northeast Corridor network. Each *.tgz (tar/gzip) archive contains data files for a given site location, named by its 3-letter code. To extract on a unix platform, use "tar -xvzf ". Data files within the -1-hr-CSV.tgz archives are comma delimited (CSV) 1-hour averages; data files within the -1-hr-NC.tgz archives are 1-hour averages in NetCDF format; data files within the -1-min-CSV.tgz are CSV files with 1-minute averages (there is no NetCDF version for 1-minute data). Site locations, heights, and other information are in a separate ascii (CSV) file (NEC_sites.csv), and also within each data file (for the 1-hour averages files). Data in this archive is for January 1 2015-January 31 2025. ASCII Readme files (Readme_v20250319.txt and Readme_1minfiles_v20250319.txt) contain file information and an Updates_v20250319.pdf file that includes additional information on updates. Note about calibrations: CO2 data are reported on the NOAA/WMO X2019 calibration scale. CH4 data are reported on the NOAA/WMO X2004A calibration scale; CO data, where available, are reported on the NOAA/WMO X2014 scale. Note that previous archives of this data reported CO2 on the X2007 scale. This data is being freely distributed for research, academic and related non-commercial purposes consistent with NIST's mandate to further the science and the promulgation of appropriate standards. Current update: March 19, 2025.

March 2025 Update. Here we provide hourly observations of atmospheric carbon dioxide (CO2), methane (CH4), and (for a few sites) carbon monoxide (CO) from tower-based sites in the NIST Northeast Corridor network. Each *.tgz (tar/gzip) archive contains data files for a given site location, named by its 3-letter code. To extract on a unix platform, use "tar -xvzf ". Data files within the -1-hr-CSV.tgz archives are comma delimited (CSV) 1-hour averages; data files within the -1-hr-NC.tgz archives are 1-hour averages in NetCDF format; data files within the -1-min-CSV.tgz are CSV files with 1-minute averages (there is no NetCDF version for 1-minute data). Site locations, heights, and other information are in a separate ascii (CSV) file (NEC_sites.csv), and also within each data file (for the 1-hour averages files). Data in this archive is for January 1 2015-January 31 2025. ASCII Readme files (Readme_v20250319.txt and Readme_1minfiles_v20250319.txt) contain file information and an Updates_v20250319.pdf file that includes additional information on updates. Note about calibrations: CO2 data are reported on the NOAA/WMO X2019 calibration scale. CH4 data are reported on the NOAA/WMO X2004A calibration scale; CO data, where available, are reported on the NOAA/WMO X2014 scale. Note that previous archives of this data reported CO2 on the X2007 scale. This data is being freely distributed for research, academic and related non-commercial purposes consistent with NIST's mandate to further the science and the promulgation of appropriate standards. Current update: March 19, 2025.

This dataset provides hourly urban greenhouse gas measurements for cities in the CO2 Urban Synthesis and Analysis (CO2-USA) Data Synthesis Network for 2000 to 2019. Measurements include carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) concentrations measured at hourly intervals at multiple sites within the U.S. cities of Boston, Indianapolis, Los Angeles, Portland, Salt Lake City, San Francisco, and Washington DC/Baltimore, and Toronto, Canada.

Hestia Project quantifies, simulates and visualizes greenhouse gases such as carbon dioxide emitted in urban regions. Los Angeles basin activity is provided at the 1 km grid spatial resolution, and at temporal resolutions of hourly or annually. Hestia-LA urban CO2 emissions inventory builds upon work conducted at the national scale (Vulcan Project) that includes various sectorial attributions. Hestia's high spatial and temporal resolution datasets are currently available for 2010 to 2015, in UTC or local time.