Atmospheric Sciences Modeling Division, Air Resources Laboratory, National Oceanic and Atmospheric Administration, in partnership with the United States Environmental Protection Agency, 109 T. W. Alexander Drive, Research Triangle Park, NC 27711, USA

Atmospheric Sciences Modeling Division, Air Resources Laboratory, National Oceanic and Atmospheric Administration, in partnership with the United States Environmental Protection Agency, 109 T. W. Alexander Drive, Research Triangle Park, NC 27711, USA

Atmospheric Sciences Modeling Division, Air Resources Laboratory, National Oceanic and Atmospheric Administration, in partnership with the United States Environmental Protection Agency, 109 T. W. Alexander Drive, Research Triangle Park, NC 27711, USA

Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, Canada

Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA