Department of Hydrology and Geo-Environmental Sciences, Faculty of Earth and Life Sciences, Vrije Universiteit, Amsterdam, Netherlands

Department of Earth System Science, University of California, Irvine, California, USA

Science Systems and Applications, Inc., NASA Goddard Space Flight Center, Greenbelt, Maryland, USA

NASA Goddard Space Flight Center, Greenbelt, Maryland, USA

Nicholas School of the Environment and Earth Sciences, Duke University, Durham, North Carolina, USA

Nicholas School of the Environment and Earth Sciences, Duke University, Durham, North Carolina, USA

now at: National Center for Atmospheric Research, Boulder, Colorado, USA