1. Scripps Institution of Oceanography; University of California, San Diego; La Jolla California USA
2. Now at Department of Atmospheric Sciences; University of Washington; Seattle Washington USA
3. NOAA Pacific Marine Environmental Laboratory; Seattle Washington USA
4. NOAA Earth System Research Laboratory; Boulder Colorado USA
5. Cooperative Institute for Research in Environmental Sciences (CIRES); University of Colorado Boulder; Boulder Colorado USA
6. Now at Planning and Policy Program, Air Pollution Control Division; Colorado Department of Public Health and Environment; Denver Colorado USA
7. Department of Chemistry and Biochemistry; University of California, San Diego; La Jolla California USA