Ocean-atmosphere-vegetation models

Are multiple ec[uilibria just a matter of the atmosphere-vegetation system, or do they occur also in the atmosphere-ocean—vegetation system So far, we have not yet found multiple solutions in the model of GanopoLski et al. (1998). (The model attains multiple solutions associated with multiple states of the thermohaline convection.) I blame this deficit on the coarse resolution of this model, because north Africa is represented by just three grid boxes, Sahara, Sudan, and tropical north Africa. Subsequently,... 

Once the model was complete, it was adjusted to a steady state condition and tested using historic carbon isotope data from the atmosphere, oceans and polar ice. Several important parameters were calculated and chosen at this stage. Sensitivity analysis indicated that results dispersal of the missing carbon - were significantly influenced by the size of the vegetation carbon pool, its assimilation rate, the concentration of preindustrial atmospheric carbon used, and the CO2 fertilization factor. The model was also sensitive to several factors related to fluxes between ocean reservoirs. 

Since neither land-surface nor ocean-surface feedbacks alone arc sufficient to explain the observed expansion of the African monsoon during the mid-Holocene, synergistic feedbacks involving land-atmosphere-ocean interactions are likely to be involved (GanopoLski ct al., 1998 Braconnot et al., 1999 Berger, in press). There have been only two attempts to examine this question. In simulations with an intermediate-complexity model, GanopoLski et al. (1998) showed that vegetation feedbacks were more important than ocean feedbacks in the amplification of the African monsoon. This simulation may not be realistic, however, because the ocean model does not re-... 

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