Global and regional drivers of nutrient supply, primary production and CO2 drawdown in the changing Arctic Ocean
Global and regional drivers of nutrient supply, primary production and CO2 drawdown in the changing Arctic Ocean
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DOI：
10.1016/j.pocean.2015.08.009
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发表时间：
2015-12
影响因子：
4.1
通讯作者：
J. Tremblay;L. Anderson;P. Matrai;P. Coupel;S. Bélanger;C. Michel;M. Reigstad
中科院分区：
文献类型：
--
作者：
J. Tremblay;L. Anderson;P. Matrai;P. Coupel;S. Bélanger;C. Michel;M. Reigstad
综述了北冰洋初级生产力空间格局、变异性和变化的主要环境因子。虽然瞬时PP率主要受影响光透过云、海冰和水的当地因素的影响，但年尺度的净PP（NPP）受影响养分供应和光可用性的远程和本地过程的层次结构的制约。养分供应设置空间差异实现或潜在的营养状态（即贫营养或富营养），而光的可用性调制PP在每个政权。通过大西洋和太平洋门户的水平营养供应明显不同，这是由于它们位于全球纬向翻转环流的两端以及太平洋部门的不平衡氮循环。河流的养分供应在当地很重要，但迄今为止似乎并不能维持整个泛北极净初级生产力的主要部分。水平营养物质输入到北冰洋表面最终转移到盐跃层通过冬季对流和分解沉降的有机物。随后重新注入这些营养物质的透光层不同的两个数量级跨部门，取决于垂直分层的强度和持久性。养分输送的这种差异与PP和NPP率的差异是相称的。地表水中广泛的氮缺乏促进了几个部门最大叶绿素（SCM）和浮游植物碳生物量次表层的出现和季节性持续。沃茨。这些层的NPP的贡献可能是在北极比在热分层的亚热带环流沃茨由于极端的驯化低光和浅nitracline在前者的组合。SCM层对地球化学通量的总体影响仍有待直接量化，无论是在区域范围内还是在泛北极尺度上。虽然北冰洋的CO2摄入量应积极响应减少海冰的范围，这有利于海气交换，温度上升和径流对CO2溶解度的负面影响可能会抵消季节性开放沃茨的PP适度增加的积极影响。总体而言，本次审查表明，海冰减少导致的光可用性的局部变化只是北冰洋PP和CO2drawdown的本地和远程驱动因素的复杂网络中的一个因素。了解和预测变化需要一个综合的生态地球化学方法，连接小北冰洋与邻近的，并充分解决垂直养分供应过程在区域和地方尺度。
The main environmental factors driving spatial patterns, variability and change in primary production (PP) in the Arctic Ocean are reviewed. While instantaneous PP rates are predominantly influenced by the local factors affecting light penetration through clouds, sea ice and water, net PP (NPP) at the annual scale is conditioned by a hierarchy of remote and local processes that affect nutrient supply and light availability in general. Nutrient supply sets spatial differences in realized or potential trophic status (i.e. oligotrophic or eutrophic), whereas light availability modulates PP within each regime. Horizontal nutrient supply through Atlantic and Pacific ocean gateways differ markedly, which is explained by their position at opposite ends of the global meridional overturning circulation and imbalanced nitrogen (N) cycling in the Pacific sector. Nutrient supply by rivers is locally important, but does not appear to sustain a major portion of overall pan-Arctic NPP so far. Horizontal nutrient inputs to the surface Arctic Ocean are eventually transferred to the halocline through winter convection and the decomposition of settling organic matter. The subsequent re-injection of these nutrients to the euphotic zone varies by two orders of magnitude across sectors, depending on the strength and persistence of the vertical stratification. Such differences in nutrient delivery are commensurate with those of PP and NPP rates. Widespread N deficiency in surface waters fosters the occurrence and seasonal persistence of subsurface layers of maximum chlorophylla(SCM) and phytoplankton carbon biomass in several sectors. The contribution of these layers to NPP is possibly higher in the Arctic than in thermally-stratified waters of the subtropical gyres due to a combination of extreme acclimation to low light and a shallow nitracline in the former. The overall impacts of SCM layers on biogeochemical fluxes remain to be quantified directly, both regionally and at the pan-Arctic scale. While CO2intake by the Arctic Ocean should respond positively to reduced sea-ice extent, which facilitates air-sea exchange, the negative influence of rising temperatures and runoff on CO2solubility might counteract the positive effect of modest PP increases in seasonally open waters. Overall, this review shows that local changes in light availability resulting from reduced sea-ice is only one factor in the intricate web of local and remote drivers of PP and CO2drawdown in the Arctic Ocean. Understanding and predicting change requires an integrated biogeochemical approach that connects the small Arctic Ocean to adjacent ones and adequately resolves vertical nutrient supply processes at regional and local scales.