Environmental Engineering Reference
In-Depth Information
Figure 2.14
Schematic illustration of the components of the coupled atmosphere-ocean-ice-land climatic system.
The full arrows are examples of external processes, and the open arrows are examples of internal processes in
climatic change
Source:
From Houghton
et al.
(1990)
take centuries or even millenia to respond
(Washington and Parkinson 1986). As a result,
running a completely interactive coupled
atmosphere-ocean model, until all elements
reach equilibrium, is time-consuming and
costly. Because of this, the oceanic element in
most coupled models is much less
comprehensive than the atmospheric element.
The ocean is commonly modelled as a slab
which represents only the uppermost layer of
water in which the temperature is relatively
uniform with depth. Oceanic heat storage is
calculated only for the chosen depth of the
layer, and other elements such as oceanic heat
transport and exchanges with the deeper parts
of the ocean are neglected or calculated
indirectly (Cubasch and Cess 1990). Thus,
although the coupling of the atmospheric and
oceanic circulations should improve the
accuracy of the modelling process, since it
more closely emulates the real environment,
the results are often no better than those
obtained from the individual uncoupled
models (Washington and Parkinson 1986).
Sea-ice models, carbon cycle models and
chemical models have also been recognized as
having the potential to contribute to climate
simulation when coupled to existing GCMs.
Sea-ice has been incorporated in some ocean
models, but separate sea-ice simulation models
have also been created. Carbon cycle models,
