It's a simulation based on ground measurement. https://svs.gsfc.nasa.gov/11719 https://svs.gsfc.nasa.gov/11719 Now we have: http://oco.jpl.nasa.gov/ http://oc

It's a simulation based on ground measurement. https://svs.gsfc.nasa.gov/11719 https://svs.gsfc.nasa.gov/11719 Now we have: http://oco.jpl.nasa.gov/ http://oco.jpl.nasa.gov/ (2014)