1 Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA, and Physical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305, USA. [email protected].
2 Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA, and Physical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305, USA.