1. Department of Atmospheric, Oceanic, and Space Sciences University of Michigan Ann Arbor Michigan USA
2. Department of Earth and Environmental Science University of Michigan Ann Arbor Michigan USA
3. Department of Earth System Science University of California Irvine California USA
4. Department of Marine Chemistry and Geochemistry Woods Hole Oceanographic Institution Woods Hole Massachusetts USA
5. Biospheric Sciences Laboratory NASA Goddard Space Flight Center Greenbelt Maryland USA
6. Nicholas School of the Environment Duke University Durham North Carolina USA
7. Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder Boulder Colorado USA
8. NOAA Earth System Research Laboratory Global Monitoring Division Boulder Colorado USA