[1] Penn State Univ, Dept Meteorol & Atmospher Sci, University Pk, PA 16801 USA
[2] North Carolina State Univ, North Carolina Inst Climate Studies, Asheville, NC 28801 USA
[3] NASA, Goddard Inst Space Studies, New York, NY 10025 USA
[4] Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA
[5] Natl Ctr Atmospher Res, Boulder, CO 80305 USA