1. NOAA/Pacific Marine Environmental Laboratory (PMEL), 7600 Sand Point Way NE, Seattle, Washington, 98115, USA;
2. The Joint Institute for the Study of the Atmosphere and Ocean (JISAO), University of Washington, Seattle, Washington, USA;
3. Department of Atmospheric Sciences, University of Washington, Seattle, Washington, USA;
4. Institute for Tropospheric Research, Leipzig, Germany