Water absorption in the atmosphere
This is actually a modelled spectrum, of the entire atmosphere (but most of it is water).
From : http://speclab.cr.usgs.gov/PAPERS.refl-mrs/refl4.html
760 nm is O2
2000 nm is CO2
2060 nm is CO2
The rest is water
Another nice reference : http://irina.eas.gatech.edu/EAS8803_Fall2009/Lec6.pdf