CO2 Transport in the Atmosphere
§The lowest layer of the model
qFrom the very first step of simulation to the end of the first year
qOnly source from fossil fuel emission
qNo sink
CO2 concentration
N-S gradient
From the talk of Dr. Fung
Mixing over Equator
      ~ 2 weeks
Mixing within a hemisphere
      ~3 months
Mixing between hemispheres
      ~ order of 1 year
Now, you can see how the CO2 from the surface is advected and diffused in the lowest layer of atmosphere.  At the first time, there was no concentration of CO2.  You can see the mixing is occurred within the Northern hemisphere which has major source regions.  There seems to be a barrier over the tropics which interrupt the mixing between the hemispheres.