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 data set provides average hourly measured, modeled enhancements, and background methane (CH4) concentrations, atmospheric ethane (C2H6) measurements, prior CH4 flux fields by sector, and a spatial reconstruction of natural gas (NG) consumption in Boston, Massachusetts and the surrounding region. Atmospheric CH4 concentrations were measured continuously from September 2012 through August 2013 at four locations and atmospheric ethane was measured continuously for several months during 2012-2014 at one location. Spatial models of prior CH4 emissions and natural gas consumption are given for an ~18,000 km^2 area centered on Boston, MA.

The Global Greenhouse Gas Reference Network for the Carbon Cycle and Greenhouse Gases (CCGG) Group is part of NOAA'S Earth System Research Laboratory (ESRL) in Boulder, CO. The Reference Network measures the atmospheric distribution and trends of the three main long-term drivers of climate change, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), as well as carbon monoxide (CO) which is an important indicator of air pollution. The Reference Network measurement program includes continuous in-situ measurements at 4 baseline observatories (global background sites) and 8 tall towers, as well as flask-air samples collected by volunteers at over 50 additional regional background sites and from small aircraft. The air samples are returned to ESRL for analysis where measurements of about 55 trace gases are done. NOAA's Global Greenhouse Gas Reference Network maintains the World Meteorological Organization international calibration scales for CO2, CH4, CO, N2O, and SF6 in air. The measurements of the Global Greenhouse Gas Reference Network serve as a comparison with measurements made by many other international laboratories, and with regional studies. They are widely used in studies inferring space-time patterns of emissions and removals of greenhouse gases that are optimally consistent with the atmospheric observations. They serve as an early warning for climate "surprises". The measurements are also helpful for the ongoing evaluation of remote sensing technologies. Observatory Measurements: NOAA/ESRL/GMD operates four staffed atmospheric baseline observatories from which numerous measurements of greenhouse gases are conducted. These baseline observatories, also known as global background sites, are located in Barrow, Alaska; Mauna Loa, Hawaii; American Samoa; and South Pole, Antarctica. The measured data are baseline levels, trends, and causes of variability of atmospheric gases that have the potential to affect global climate. These observatories were established in order to provide a sampling of the most remote air on the planet so that the true "background atmosphere" could be monitored. GMD first began continuous in-situ measurements of CO2 at these observatories in 1973, and added CH4 and CO measurements in the 1980's. The ongoing data set is contingent upon the baseline observatories that are still in use going forward. A subset of Observatory Measurements for only carbon dioxide (CO2) taken from Observatories is archived separately with digital object identifiers (DOIs) for each of the four observation stations listed above. The observations run from 1973 through the end of 2016. The main portion of this agreement is for the enhanced "version" of the more encompassing dataset for all of the different types of observation platforms and gases. Through the Big Earth Data Initiative (BEDI), ESRL/GMD has taken their data collection and converted files into NetCDF-4, a self-describing format.

The Global Greenhouse Gas Reference Network for the Carbon Cycle and Greenhouse Gases (CCGG) Group is part of NOAA'S Earth System Research Laboratory (ESRL) in Boulder, CO. The Reference Network measures the atmospheric distribution and trends of the three main long-term drivers of climate change, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), as well as carbon monoxide (CO) which is an important indicator of air pollution. The Reference Network measurement program includes continuous in-situ measurements at 4 baseline observatories, also known as global background sites, and 8 tall towers, as well as flask-air samples collected by volunteers at over 50 additional sites, also known as regional background sites, and from small aircraft. The air samples are returned to ESRL for analysis where measurements of about 55 trace gases are done. NOAA's Global Greenhouse Gas Reference Network maintains the World Meteorological Organization international calibration scales for CO2, CH4, CO, N2O, and SF6 in air. The measurements of the Global Greenhouse Gas Reference Network serve as a comparison with measurements made by many other international laboratories, and with regional studies. They are widely used in studies inferring space-time patterns of emissions and removals of greenhouse gases that are optimally consistent with the atmospheric observations. They serve as an early warning for climate "surprises". The measurements are also helpful for the ongoing evaluation of remote sensing technologies. Tall Tower Measurements: ESRL's Global Monitoring Division (GMD) began making measurements from tall towers in the 1990s in order to extend long-term carbon-cycle gas monitoring to continental areas. Existing television, radio and cell phone towers are utilized as sampling platforms for continuous in-situ sampling of CO2 and other atmospheric trace gases, including carbon monoxide (CO) in the continental boundary layer. The measured data are baseline levels, trends, and causes of variability of atmospheric gases that have the potential to affect global climate. The tall tower sites are part of the North American Carbon Program and are a primary data source for ESRL's Carbon Tracker CO2 data assimilation system. The historic data set is from 8 tall towers. The ongoing data set is contingent upon the observation sites that are still in use going forward. Through the Big Earth Data Initiative (BEDI), ESRL/GMD has taken their data collection and converted files into NetCDF-4, a self-describing format.

The Global Greenhouse Gas Reference Network for the Carbon Cycle and Greenhouse Gases (CCGG) Group is part of NOAA'S Earth System Research Laboratory (ESRL) in Boulder, CO. The Reference Network measures the atmospheric distribution and trends of the three main long-term drivers of climate change, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), as well as carbon monoxide (CO) which is an important indicator of air pollution. The Reference Network measurement program includes continuous in-situ measurements at 4 baseline observatories, also known as global background sites, and 8 tall towers, as well as flask-air samples collected by volunteers at over 50 additional sites, also known as regional background sites, and from small aircraft. The air samples are returned to ESRL for analysis where measurements of about 55 trace gases are done. NOAA's Global Greenhouse Gas Reference Network maintains the World Meteorological Organization international calibration scales for CO2, CH4, CO, N2O, and SF6 in air. The measurements of the Global Greenhouse Gas Reference Network serve as a comparison with measurements made by many other international laboratories, and with regional studies. They are widely used in studies inferring space-time patterns of emissions and removals of greenhouse gases that are optimally consistent with the atmospheric observations. They serve as an early warning for climate "surprises". The measurements are also helpful for the ongoing evaluation of remote sensing technologies. Tall Tower Measurements: ESRL's Global Monitoring Division (GMD) began making measurements from tall towers in the 1990s in order to extend long-term carbon-cycle gas monitoring to continental areas. Existing television, radio and cell phone towers are utilized as sampling platforms for continuous in-situ sampling of CO2 and other atmospheric trace gases, including carbon monoxide (CO) in the continental boundary layer. The measured data are baseline levels, trends, and causes of variability of atmospheric gases that have the potential to affect global climate. The tall tower sites are part of the North American Carbon Program and are a primary data source for ESRL's Carbon Tracker CO2 data assimilation system. The historic data set is from 8 tall towers. The ongoing data set is contingent upon the observation sites that are still in use going forward. Through the Big Earth Data Initiative (BEDI), ESRL/GMD has taken their data collection and converted files into NetCDF-4, a self-describing format.

The Global Greenhouse Gas Reference Network for the Carbon Cycle and Greenhouse Gases (CCGG) Group is part of NOAA'S Earth System Research Laboratory (ESRL) in Boulder, CO. The Reference Network measures the atmospheric distribution and trends of the three main long-term drivers of climate change, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), as well as carbon monoxide (CO) which is an important indicator of air pollution. The Reference Network measurement program includes continuous in-situ measurements at 4 baseline observatories (global background sites) and 8 tall towers, as well as flask-air samples collected by volunteers at over 50 additional regional background sites and from small aircraft. The air samples are returned to ESRL for analysis where measurements of about 55 trace gases are done. NOAA's Global Greenhouse Gas Reference Network maintains the World Meteorological Organization international calibration scales for CO2, CH4, CO, N2O, and SF6 in air. The measurements of the Global Greenhouse Gas Reference Network serve as a comparison with measurements made by many other international laboratories, and with regional studies. They are widely used in studies inferring space-time patterns of emissions and removals of greenhouse gases that are optimally consistent with the atmospheric observations. They serve as an early warning for climate "surprises". The measurements are also helpful for the ongoing evaluation of remote sensing technologies. The CCGG cooperative air sampling network effort began in 1967 at Niwot Ridge, Colorado. Today, the network is an international effort which includes regular discrete samples from the NOAA ESRL/GMD baseline observatories, cooperative fixed sites, and commercial ships. Air samples are collected approximately weekly from a globally distributed network of sites. Samples are analyzed for Carbon Dioxide (CO2), Methane (CH4), Carbon Monoxide (CO), Hydrogen Gas (H2), Nitrous Oxide (N2O), and Sulfur Hexafluoride (SF6); and by INSTAAR for the stable isotopes of CO2 and CH4 and for many volatile organic compounds (voc) such as ethane (C2H6), ethylene (C2H4) and propane (C3H8). Measurement data are used to identify long-term trends, seasonal variability, and spatial distribution of carbon cycle gases. Through the Big Earth Data Initiative (BEDI), ESRL/GMD has taken their data collection and converted files into NetCDF-4, a self-describing format.

The Global Greenhouse Gas Reference Network for the Carbon Cycle and Greenhouse Gases (CCGG) Group is part of NOAA'S Earth System Research Laboratory (ESRL) in Boulder, CO. The Reference Network measures the atmospheric distribution and trends of the three main long-term drivers of climate change, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), as well as carbon monoxide (CO) which is an important indicator of air pollution. The Reference Network measurement program includes continuous in-situ measurements at 4 baseline observatories (global background sites) and 8 tall towers, as well as flask-air samples collected by volunteers at over 50 additional regional background sites and from small aircraft. The air samples are returned to ESRL for analysis where measurements of about 55 trace gases are done. NOAA's Global Greenhouse Gas Reference Network maintains the World Meteorological Organization international calibration scales for CO2, CH4, CO, N2O, and SF6 in air. The measurements of the Global Greenhouse Gas Reference Network serve as a comparison with measurements made by many other international laboratories, and with regional studies. They are widely used in studies inferring space-time patterns of emissions and removals of greenhouse gases that are optimally consistent with the atmospheric observations. They serve as an early warning for climate "surprises". The measurements are also helpful for the ongoing evaluation of remote sensing technologies. The CCGG cooperative air sampling network effort began in 1967 at Niwot Ridge, Colorado. Today, the network is an international effort which includes regular discrete samples from the NOAA ESRL/GMD baseline observatories, cooperative fixed sites, and commercial ships. Air samples are collected approximately weekly from a globally distributed network of sites. Samples are analyzed for Carbon Dioxide (CO2), Methane (CH4), Carbon Monoxide (CO), Hydrogen Gas (H2), Nitrous Oxide (N2O), and Sulfur Hexafluoride (SF6); and by INSTAAR for the stable isotopes of CO2 and CH4 and for many volatile organic compounds (voc) such as ethane (C2H6), ethylene (C2H4) and propane (C3H8). Measurement data are used to identify long-term trends, seasonal variability, and spatial distribution of carbon cycle gases. Through the Big Earth Data Initiative (BEDI), ESRL/GMD has taken their data collection and converted files into NetCDF-4, a self-describing format.

This dataset provides in situ airborne measurements of atmospheric carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and water vapor concentrations, plus air temperature, pressure, relative humidity, and wind speed values over Alaska and the Yukon and Northwest Territories of Canada during the Arctic Carbon Aircraft Profile (Arctic-CAP) monthly sampling campaigns from April-November 2017. Observations have been averaged to a 10-second interval and are reported with the number of samples (N) and standard deviation. During each of the six monthly campaigns, flights over the Arctic-Boreal Vulnerability Experiment (ABoVE) domain included 25 vertical profiles, from the surface up to 6 km altitude, at locations selected to complement regular long-term vertical profiles, remote sensing data, and ground-based flux tower measurements.

,This data package was produced by researchers working on the Shortgrass Steppe Long Term Ecological Research (SGS-LTER) Project, administered at Colorado State University. Long-term datasets and background information (proposals, reports, photographs, etc.) on the SGS-LTER project are contained in a comprehensive project collection within the Digital Collections of Colorado (http://digitool.library.colostate.edu/R/?func=collections&collection_id=3429). The data table and associated metadata document, which is generated in Ecological Metadata Language, may be available through other repositories serving the ecological research community and represent components of the larger SGS-LTER project collection. Additional information and referenced materials can be found: http://hdl.handle.net/10217/82454. Single leaf gas exchange (CO2 & H2O) was measured several times per season on important grass species in the shortgrass steppe open-top-chamber experiment. Cuvette light levels were varied to investigate physiological adaptations to elevated CO2. This research was conducted at the Central Plains Experimental Range, near Nunn, CO; lat.40degrees 40 minutes N; long. 104 degrees 45 minutes W in the shortgrass steppe region of NE Colorado, USA and as a collaboration between SGS-LTER and USDA-ARS researchers.,,