This Atmospheric Tomography Mission (ATom) dataset provides O2/N2, CO2, Ar/N2, and stable isotope ratios of CO2 measured by the Medusa Whole Air Sampler. Medusa provides discretely-sampled comparisons for on-board in situ O2/N2 ratio and CO2 measurements and unique measurements of Ar/N2 and 13C, 14C, and 18O isotopologues of CO2. The complementary measurements allow ground-truthing of on-board instrument measurements in a laboratory setting, where analysis conditions can often be more stringently controlled and carefully monitored. Isotope and argon measurements can provide additional information about land and ocean controls over the carbon cycle, and about the age and source of the air sampled.
Data Citation: Morgan, E.J., B.B. Stephens, J. Bent, A. Watt, S. Afshar, W. Paplawsky, and R.F. Keeling. 2019. ATom: L2 Measurements from Medusa Whole Air Sampler (Medusa). ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/1729
This dataset from ATom provides the atmospheric volume mixing ratio of formaldehyde measured by NASA's In Situ Airborne Formaldehyde (ISAF) instrument. The instrument uses laser-induced fluorescence (LIF) to obtain the high detection sensitivity needed to detect formaldehyde in the upper troposphere and lower stratosphere where abundances are 10 parts per trillion. LIF also enables a fast time response needed to measure the abundance of formaldehyde in the finely structured outflow of convective storms. These measurements of formaldehyde will be used to elucidate mechanisms of convective transport and quantify the effects of boundary layer pollutants on the ozone photochemistry and cloud microphysics of the upper atmosphere.
Data Citation: Hanisco, T.F., H. Bian, J.M. Nicely, X. Pan, R.A. Hannun, J.M. St.Clair, and G.M. Wolfe. 2019. ATom: L2 Measurements of In Situ Airborne Formaldehyde (ISAF). ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/1730
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 the 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. See all ORNL DAAC data from ATom.