Potential role of oceanic mixed layer dynamics on the model climate sensitivity
In: Journal of Marine Systems. Elsevier: Tokyo; Oxford; New York; Amsterdam. ISSN 0924-7963; e-ISSN 1879-1573, more
Also appears in:Nihoul, J.C.J. (Ed.) (1990). Coupled ocean-atmosphere modeling: proceedings of the 21th International Liège Colloquium on Ocean Hydrodynamics, Liège, May 8-12, 1989. Journal of Marine Systems, 1(1-3). Elsevier Scientific: Amsterdam. 313 pp., more
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| Abstract |
A seasonal resolution, multi-box energy balance model has been developed to simulate the climate changes arising as a result of natural or anthropogenous influences. The model divides the global climatic system into 12 interactive domains according to the real geographical structure. The domains are separated by a surface (ocean-, land- or cryosphere-type) and an atmospheric block. The ocean-type surface block is based on a one dimensional Hoffert-type ocean submodel, but the depth of the oceanic mixed layer can vary in connection with the surface processes. The climatic variables of the domains are the surfaces and air temperatures and—in the case of the oceanic type surfaces—the mixed layer depth. The calculations show that the dynamics of the mixed layer can be attributed to the essential deviation, with respect to the constant mixed layer depth in the basic climate experiments. The equilibrium climate sensitivity has been analyzed in two cases. The modelled warming for a doubling in CO2 is 2.2° C for a constant mixed layer depth and 1.3° C for a variable mixed layer thickness. The global temperature response to a 1% change in the solar constant is a change in temperature of 1.5° C for a “frozen” mixed layer depth and 0.9° C for a dynamically mixed layer. These experiments reveal that the mixed layer dynamics can play an enhanced role in the behaviour of the modelled climate system. |
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