Marine phytoplankton contributes nearly half of the total primary production on Earth through photosynthesis. Parameterizations of algal photosynthesis commonly employed in global biogeochemical simulations generally fail to capture the observed vertical structure of primary production. Here we examined the consequences of decoupling photosynthesis (carbon fixation) and biosynthesis (biomass building) with accumulation or exudation of excess photosynthate under energy rich conditions in both regional and global models. The results show that the decoupling of these two processes improved the simulated vertical profile of primary production, increased modeled primary production over 30% globally and over 40% in subtropical oceans, improved simulated meridional patterns of particulate C:N:P and increased modeled surface pool of labile/semi-labile dissolved organic carbon. More generally, these results highlight the importance of exudation, which results from the decoupling of photosynthesis and biosynthesis, as a major physiological process affecting ocean biogeochemistry.

中文翻译：

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模拟亚热带海洋的光合作用和渗出

海洋浮游植物通过光合作用占地球初级生产总量的近一半。全球生物地球化学模拟中常用的藻类光合作用参数化通常无法捕捉观察到的初级生产的垂直结构。在这里，我们在区域和全球模型中研究了在能量丰富的条件下光合作用（碳固定）和生物合成（生物质构建）与过量光合产物的积累或渗出分离的后果。结果表明，这两个过程的分离改善了初级生产的模拟垂直剖面，将模拟初级生产在全球范围内增加了 30% 以上，在亚热带海洋中增加了 40% 以上，改进了颗粒 C:N 的模拟子午模式：P 和增加的不稳定/半不稳定溶解有机碳的模拟表面池。更一般地说，这些结果强调了渗出的重要性，渗出是光合作用和生物合成脱钩的结果，是影响海洋生物地球化学的主要生理过程。