1. Department of Earth, Environment and Planetary Sciences; Brown University; Providence Rhode Island USA
2. The Ecosystems Center; Marine Biological Laboratory; Woods Hole Massachusetts USA
3. Remote Sensing of Environmental Dynamics Laboratory, DISAT; Universit`a degli Studi Milano-Bicocca; Milan Italy
4. NASA Goddard Space Flight Center; Greenbelt Maryland USA
5. School of Engineering and Applied Sciences and Department of Earth and Planetary Sciences; Harvard University; Cambridge Massachusetts USA
6. Department of Global Ecology; Carnegie Institution for Science; Stanford California USA
7. Department of Organismic and Evolutionary Biology; Harvard University; Cambridge Massachusetts USA