Incorporation of Physical Processes

The climate system, as has been discussed earlier, includes the atmosphere, ocean, land surface, biosphere, and ice masses. Models of the climate system must in some way consider the influences of each of these components. For instance, surface winds drive ocean currents and create waves that promote mixing in the upper layer of the ocean. This horizontal movement and vertical mixing of ocean water transports heat poleward from tropical and subtropical regions and downward from the surface. The heat transported poleward is given up to the atmosphere at higher latitudes. Failure to include ocean heat transport would create serious deficiencies in atmospheric global climate models.

Ocean circulation modeling has proceeded in parallel with atmospheric modeling and is based on the same set of basic equations as the atmosphere (except the equation of state and density are different). The atmosphere exchanges heat, moisture, and trace gases (notably CO₂ ) with the ocean, but the rates of change of temperature and speed of movement are much lower in the ocean.

Despite the difficult challenges posed by bringing together two complex numerical models, climate scientists have successfully coupled atmospheric and ocean circulation models. These ocean models may be fairly simple (simple heat diffusion poleward) or complex and use the full equations of motion as for the atmosphere.

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