Methane (CH4) mole fraction data collected from three tower sites in the Washington DC area: Bucktown, MD (BUC, ghg01), Stafford, VA (SFD, ghg65), and Thurmont, MD (TMD, ghg61), as part of NIST's Northeast Corridor Urban Testbed project, presented as 1-minute averages. This data is published for research academic and related non-commercial purposes consistent with NIST’s mandate to further the science and the promulgation of appropriate standards. This dataset was used in the following publication and this archive represents the static archive of the data used in the publication and is not updated or modified: Sahu, S., Ahn, D., Loughner, C., and Dickerson, R., "Influence of synoptic weather patterns on methane mixing ratios in the Baltimore/Washington region", Atmospheric Environment, Volume 334, 2024, 120675, ISSN 1352-2310,https://doi.org/10.1016/j.atmosenv.2024.120675.Data is described further in the Readme document and references cited within.

Hourly methane mole fraction data collected from four tower sites in the Washington DC and Baltimore MD region as part of NIST's Northeast Corridor project. Dataset accompanying publication "Seasonally resolved excess urban methane emissions from the Baltimore/Washington, DC metropolitan region" by Huang, Y., Kort, E. A., Gourdji, S., Karion, A., Mueller, K., and Ware, J.: Seasonally Resolved Excess Urban Methane Emissions from the Baltimore/Washington, DC Metropolitan Region, Environ. Sci. Technol., 10.1021/acs.est.9b02782, 2019. Data is described further in the publication and readme document.

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.

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.

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.

WARNING: There is a more recent version of this data set. Please visit https://doi.org/10.18434/mds2-3012 for the update. Do not use this data. Contact Anna.Karion@nist.gov with questions.Hourly observations of CO2 and CH4 from tower-based sites in the NIST Northeast Corridor network (currently 23, but more may be added in future updates); CO observations from one site. 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 is in a separate ascii (CSV) file (NEC_sites.csv). Data is currently reported for the years 2015-2019, with planned annual updates. An ASCII Readme file (NEC_Readme_10052020) is also posted, along with an Updates_10052020.txt file that includes information on updates. Current update: Nov 11, 2020. See also associated publication (Karion et al., Earth System Science Data, 2020): https://doi.org/10.5194/essd-12-699-2020

NOTE: please see the latest (March 2025) update at https://doi.org/10.18434/mds2-3765 . This archive is from November 2021.We have become aware of errors in the inlet heights at multiple sites and have corrected these in the newest version. Hourly observations of CO2 and CH4 from tower-based sites in the NIST Northeast Corridor network; CO observations from one site. 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 is in a separate ascii (CSV) file (NEC_sites.csv). Data in this archive is reported for the years 2015-2020. An ASCII Readme file (NEC_Readme_11012021) is also posted, along with an Updates_11012021.txt file that includes information on updates. In this update, we added a new directory with Obspack-formatted text and netcdf files for users familiar with those data formats (https://gml.noaa.gov/ccgg/obspack/), and have added Kenneth Schuldt (NOAA-GML and CIRES), who generated this ObsPack, to the data citation. These files include all years 2015-2020. 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: Nov 1, 2021.

This dataset provides the hourly average of continuous atmospheric measurements of methane (CH4) from two urban sites and three boundary sites in and around Boston, Massachusetts, U.S., from September 2012-May 2020, measured with Picarro cavity ring down spectrometers (CRDS). Five-minute average atmospheric measurements of ethane (C2H6) and methane at Copley Square in Boston, MA, are also provided, with ethane measured with a laser spectrometer and methane measured with a Picarro CRDS. Background CH4 concentrations for the urban sites were determined using Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model trajectories at the boundary of the study region based on measurements at three boundary sites and wind direction from the North American Mesoscale Forecast System (NAM) 12-kilometer meteorology.

This dataset provides the hourly average of continuous atmospheric measurements of methane (CH4) from two urban sites and three boundary sites in and around Boston, Massachusetts, U.S., from September 2012-May 2020, measured with Picarro cavity ring down spectrometers (CRDS). Five-minute average atmospheric measurements of ethane (C2H6) and methane at Copley Square in Boston, MA, are also provided, with ethane measured with a laser spectrometer and methane measured with a Picarro CRDS. Background CH4 concentrations for the urban sites were determined using Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model trajectories at the boundary of the study region based on measurements at three boundary sites and wind direction from the North American Mesoscale Forecast System (NAM) 12-kilometer meteorology.

The CMS Methane (CH4) Flux for North America data set contains estimates of methane emission in North America based on an inversion of the GEOS-Chem chemical transport model constrained by Greenhouse Gases Observing SATellite (GOSAT) observations. The nested approach of the inversion enables large point sources to be resolved while aggregating regions with weak emissions and minimizing aggregation errors. The emission sources are separated into 12 different sectors as follows: Total, Oil/Gas, Coal, Cows, Waste (Landfills+ Wastewater), Biofuel, Rice, Other Anthropogenic, Biomass Burning, Wetlands, Soil Absorption, Other Natural. More details about the algorithm and error characterization can be found in Turner, Jacob, Wecht, et al. 2015.The NASA Carbon Monitoring System (CMS) is designed to make significant contributions in characterizing, quantifying, understanding, and predicting the evolution of global carbon sources and sinks through improved monitoring of carbon stocks and fluxes. The System will use the full range of NASA satellite observations and modeling/analysis capabilities to establish the accuracy, quantitative uncertainties, and utility of products for supporting national and international policy, regulatory, and management activities. CMS will maintain a global emphasis while providing finer scale regional information, utilizing space-based and surface-based data and will rapidly initiate generation and distribution of products both for user evaluation and to inform near-term policy development and planning.