Ross J Salawitch¹, Laura McBride², Brian Francis Bennett³, Peter von Der Gathen⁴, Ingo Wohltmann⁴, Markus Rex⁴, Martyn Chipperfield⁵, Melanie Coldewey-Egbers⁶, Sandip Dhomse⁵, Vitali Fioletov⁷, Stacey M Frith⁸, Laila Howar¹, Jos de Laat⁹, Diego G Loyola¹⁰, Emmanuel Mahieu¹¹, Maxime Prignon¹², Wolfgang Steinbrecht¹³, Ronald van der A⁹, Pam Wales¹⁴, Mark Weber¹⁵ and Jeannette Wild¹⁶, (1)University of Maryland College Park, College Park, MD, United States, (2)Science and Technology Corporation, Boulder, United States, (3)University of Maryland, Department of Atmospheric and Oceanic Science, College Park, MD, United States, (4)Alfred Wegener Institute, Helmholtz-Center for Polar and Marine Research Potsdam, Potsdam, Germany, (5)University of Leeds, School of Earth and Environment, Leeds, United Kingdom, (6)German Aerospace Center DLR Oberpfaffenhofen, Remote Sensing Technology Institute (IMF), Oberpfaffenhofen, Germany, (7)Environment and Climate Change Canada, Air Quality Research Division, Downsview, ON, Canada, (8)NASA Goddard SFC, Greenbelt, United States, (9)Royal Netherlands Meteorological Institute, De Bilt, Netherlands, (10)German Aerospace Center (DLR), Remote Sensing Technology Institute (IMF), Oberpfaffenhofen, Germany, (11)University of Liège, Institut d’Astrophysique et de Geophysique, UR SPHERES, Liège, Belgium, (12)Université de Liège, Liege, Belgium, (13)Deutscher Wetterdienst, Lindenberg, Germany, (14)University of Maryland College Park, College Park, United States, (15)University of Bremen, Institute of Environmental Physics, Bremen, Germany, (16)NOAA NWS NCEP, Climate Prediction Center, College Park, MD, United States