1. Department of Atmospheric and Oceanic Sciences, University of Wisconsin–Madison, Madison, Wisconsin, USA
2. Space Science and Engineering Center, University of Wisconsin–Madison, Madison, Wisconsin, USA
3. Department of Atmospheric and Earth Science, The University of Alabama in Huntsville, Huntsville, Alabama, USA
4. Now at Iowa Technology Institute, College of Engineering, The University of Iowa, Iowa City, Iowa, USA
5. Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado, USA
6. Department of Atmospheric, Oceanic and Earth Sciences, George Mason University, Fairfax, Virginia, USA