1. Climate Research Division; Environment Canada; Toronto Ontario Canada
2. Department of Physics; University of Waterloo; Waterloo Ontario Canada
3. School of Life Sciences; Arizona State University; Tempe Arizona USA
4. Oak Ridge National Laboratory; Oak Ridge Tennessee USA
5. Colorado State University; Fort Collins Colorado USA
6. Global Monitoring Division, National Oceanic and Atmospheric Administration; Earth System Research Laboratory; Boulder Colorado USA
7. Department of Physics; University of Toronto; Toronto Ontario Canada