Elsevier, Deep Sea Research Part II: Topical Studies in Oceanography, 10(48), p. 2173-2197
DOI: 10.1016/s0967-0645(00)00184-3
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Model-derived estimates of marine new production are found to display systematic covariations with the underlying model architecture. Almost regardless of the formulation of biogeochemical processes, model-derived estimates of new production have more than doubled from about to values around when turning from early box models to more recent investigations using coarse-resolution general circulation models. Because none of these models resolves eddies, which have been shown to enhance biological production, a further increase in simulated new production with increasing model resolution might be expected. This study presents results from an eddy-permitting coupled biological–physical model that suggest a basin-scale new production of less than for the North Atlantic, i.e. substantially less than values typical for coarse-resolution models. Sensitivity experiments reveal that the amount of diapycnal mixing, described either explicitly or implicitly in the numerical discretization schemes, has a considerable effect on the simulated input of nutrients into the euphotic zone. Implications for coarse-resolution models used until now are that unrealistically high levels of explicit and implicit diapycnal diffusion may have been responsible for unrealistically high estimates of new production.