1. Air Quality Research Division Environment and Climate Change Canada Downsview ON Canada
2. Institute for Energy and Climate Research: Troposphere (IEK‐8) Research Centre Juelich (FZJ) Juelich Germany
3. NASA Goddard Space Flight Center Greenbelt MD USA
4. St. Edward's University Austin TX USA
5. Earth Observing Laboratory National Center for Atmospheric Research Boulder CO USA
6. Japan Meteorological Agency Tokyo Japan
7. Royal Meteorological Institute of Belgium Brussels Belgium
8. NASA Goddard Space Flight Center and University of Maryland Earth System Science Interdisciplinary Center MD USA
9. NOAA/ESRL Global Monitoring Division Boulder CO USA
10. MeteoSwiss Aerological Station Federal Office of Meteorology and Climatology MeteoSwiss Payerne Switzerland
11. National Center for Atmospheric Research Boulder CO USA