Bharat Rastogi¹, Caroline B Alden^2,3, Michael Trudeau³, Lei Hu⁴, Kirk W Thoning⁵, John B Miller⁶, Marikate Ellis Mountain⁷, Thomas Nehrkorn⁸, Anna M Michalak⁹, Arlyn E Andrews¹⁰ and Kaiyu Guan¹¹, (1)NOAA Boulder, Boulder, United States, (2)Stanford University, Stanford, CA, United States, (3)Cooperative Institute for Research in Environmental Sciences, Boulder, CO, United States, (4)NOAA/ESRL GMD, Boulder, CO, United States, (5)NOAA Boulder, Boulder, CO, United States, (6)NOAA, ESRL/GMD, Boulder, CO, United States, (7)Atmospheric and Environmental Research, Lexington, MA, United States, (8)AER Inc, Lexington, MA, United States, (9)Carnegie Institution for Science, Washington, DC, United States, (10)NOAA/ESRL, Global Monitoring Division, Boulder, CO, United States, (11)University of Illinois at Urbana Champaign, College of Agricultural, Consumer and Environmental Sciences, Urbana, IL, United States