The ORNL DAAC recently released an update to the following Atmospheric Tomography Mission (ATom) dataset by Allen, H.M., et al. (2021):
ATom: In Situ Data from Caltech Chemical Ionization Mass Spectrometer (CIT-CIMS), V2
This dataset provides the concentrations of gas-phase organic and inorganic analytes measured by the California Institute of Technology (CIT) Chemical Ionization Mass Spectrometer (CIMS), or CIT-CIMS, flown on the NASA DC-8 aircraft during the four ATom campaigns. The CIT-CIMS employs CF3O-ion chemistry with two independent mass spectrometers (compact time-of-flight and triple quadrupole) to enable sensitive and specific measurements of atmospheric trace gases. The measurements include hydrogen peroxide (H2O2), hydrogen cyanide (HCN), nitric acid (HNO3), methyl hydrogen peroxide (CH3OOH), peroxyacetic acid (C2O3H4), peroxynitric acid (HO2NO2), and sulfur dioxide (SO2), in units of parts-per-trillion-by-volume.
This is Version 2 of this dataset. Version 2 contains the initial release of files for the ATom-4 campaign and CIT-SO2 files for the ATom-3 campaign. Additional details can be found in Section 8: Dataset Revisions, within the User Guide documentation.
The Atmospheric Tomography Mission (ATom) is a NASA Earth Venture Suborbital-2 mission to study the impact of human-produced air pollution on greenhouse gases and on chemically reactive gases in the atmosphere. ATom deployed an extensive gas and aerosol payload on the NASA DC-8 aircraft for systematic, global-scale sampling of the atmosphere, profiling continuously from 0.2 to 12 km altitude. Around-the-world flights were conducted in each of four seasons between 2016 and 2018.
Additional data from ATom and other relevant links can be found on the ORNL DAAC's ATom Project Page.
Citation: Allen, H.M., J.D. Crounse, M.J. Kim, A.P. Teng, L. Xu, and P.O. Wennberg. 2021. ATom: In Situ Data from Caltech Chemical Ionization Mass Spectrometer (CIT-CIMS), V2. ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/1927