In Situ Carbon Dioxide, Methane, and Carbon Monoxide Mole Fractions from the Los Angeles Megacity Carbon Project

NOTE: please see the latest (April 2025) update at https://doi.org/10.18434/mds2-3814 . 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.