1. Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
2. Department of Chemistry, California Institute of Technology, Pasadena, California 91125, United States
3. Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
4. Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
5. Atmospheric Research & Analysis, Inc., Cary, North Carolina 27513, United States
6. Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, United States