1. National Center for Atmospheric Research; Boulder; Colorado; USA
2. Instituto de Fisca; Universidade de Sao Paulo; Sao Paulo; Brazil
3. School of Environmental Sciences; University of East Anglia; Norwich; UK
4. Department of Environmental Sciences; University of Virginia; Charlottesville; Virginia; USA
5. Earth System Science Department; University of California; Irvine; California; USA
6. Department of Ecology and Evolutionary Biology and Institute of Arctic and Alpine Research; University of Colorado; Boulder; Colorado; USA