Atmospheric Chemistry and Dynamics Branch, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA

Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, Maryland, USA

now at: Meteorologisches Observatorium Lindenberg, Deutscher Wetterdienst, Tauche, Germany

Institut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt (DLR) Oberpfaffenhofen, Weßling, Germany

Atmospheric Chemistry and Dynamics Branch, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA

Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, Maryland, USA

Department of Atmospheric Sciences, Texas A&M University, College Station, Texas, USA

Atmospheric Chemistry and Dynamics Branch, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA