Iron release from melting continental and sea ice is deemed important for phytoplankton, the growth of which is iron-limited in the Southern Ocean. Both sources are generally considered separately, yet their effects on the biological carbon pump could interact. Using a global ocean-sea-ice-biogeochemical model with a representation of both continental and sea ice iron sources, we find them to have an overall additive effect on phytoplankton activity, increasing carbon export by +13.9% of the Southern Ocean total, with continental ice contributing +4.5% and sea ice +8.0%. The +1.4% residual is due to a coupled fertilization effect: When the iron source from continental ice is activated, iron in sea ice increases by 16%, so does iron transport toward low production areas. Overall, this increases phytoplankton activity: Fertilization is more efficient where sea ice melts than at locations of initial iron release by continental ice.

中文翻译：

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大陆和海冰铁源协同滋养南大洋

融化的大陆和海冰释放的铁被认为对浮游植物很重要，浮游植物的生长在南大洋受到铁的限制。这两种来源通常单独考虑，但它们对生物碳泵的影响可能会相互作用。使用代表大陆和海冰铁源的全球海洋-海-冰-生物地球化学模型，我们发现它们对浮游植物活动具有整体叠加效应，使南大洋总量的碳出口增加 +13.9%，与大陆冰贡献 +4.5%，海冰 +8.0%。+1.4% 的残留是由于耦合施肥效应：当大陆冰中的铁源被激活时，海冰中的铁会增加 16%，铁向低产区的运输也会增加。总的来说，这会增加浮游植物的活动：