Benjamin Birner¹, Martyn Chipperfield², Eric James Morgan¹, Britton B Stephens³, Marianna Linz⁴, Wuhu Feng², Chris J Wilson⁵, Jonathan D Bent⁶, Eric J Hintsa⁷, Jeffrey P Severinghaus¹ and Ralph F Keeling⁸, (1)Scripps Institution of Oceanography, La Jolla, CA, United States, (2)University of Leeds, School of Earth and Environment, Leeds, United Kingdom, (3)National Center for Atmospheric Research, Earth Observing Laboratory, Boulder, CO, United States, (4)University of California, Los Angeles, Los Angeles, CA, United States, (5)University of Leeds, Leeds, LS2, United Kingdom, (6)Scripps Inst of Oceanography, La Jolla, CA, United States, (7)Cooperative Institute for Research in Environmental Sciences, NOAA/ESRL Global Monitoring Division, Boulder, CO, United States, (8)Univ California San Diego, La Jolla, CA, United States