Preformed and regenerated phosphate in ocean general circulation models: can right total concentrations be wrong?

[摘要] Phosphate distributions simulated by seven state-of-the-art biogeochemical ocean circulationmodels are evaluated against observations of global ocean nutrient distributions. Thebiogeochemical models exhibit different structural complexities, ranging from simplenutrient-restoring to multi-nutrient NPZD type models. We evaluate the simulations using theobserved volume distribution of phosphate. The errors in these simulated volume classdistributions are significantly larger when preformed phosphate (or regenerated phosphate) ratherthan total phosphate is considered. Our analysis reveals that models can achieve similarly goodfits to observed total phosphate distributions for a~very different partitioning into preformedand regenerated nutrient components. This has implications for the strength and potential climatesensitivity of the simulated biological carbon pump. We suggest complementing the use of totalnutrient distributions for assessing model skill by an evaluation of the respective preformed andregenerated nutrient components.

[学科分类] 地球化学与岩石