Recycled iron fuels new production in the eastern equatorial Pacific Ocean.
Recycled iron fuels new production in the eastern equatorial Pacific Ocean.
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DOI：
10.1038/s41467-017-01219-7
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发表时间：
2017-10-24
影响因子：
16.6
通讯作者：
Mackey KRM
中科院分区：
文献类型：
--
作者：
Rafter PA;Sigman DM;Mackey KRM
硝酸盐持续存在于赤道东太平洋表层水域，因为硝酸盐（新产量）推动的浮游植物生长受到铁的限制。硝酸盐同位素测量为该区域表面硝酸盐浓度的控制提供了新的约束，并使我们能够量化硝酸盐消耗的程度和时间变化。在这里，我们表明，这些水域中硝酸盐的消耗不能仅仅通过外部向这些水域供应铁来推动，而铁是通过上升流和灰尘沉积而发生的。相反，相当一部分硝酸盐消耗必须由地表水中铁的回收来支持。考虑到合理的铁回收率，赤道内外硝酸盐浓度的季节性变化可以通过上升流速率来解释，较慢的上升流允许更多的铁再生和吸收循环。赤道太平洋铁循环的效率意味着生态系统层面的机制的演变，该机制将铁保留在限制生产力的表层海洋环境中。在赤道东太平洋，上升流提供的硝酸盐超过了浮游植物的需求量。在这里，作者使用硝酸盐同位素表明，地表水中的铁循环支持硝酸盐的消耗，降低了表面硝酸盐浓度并解释了其变化。
Nitrate persists in eastern equatorial Pacific surface waters because phytoplankton growth fueled by nitrate (new production) is limited by iron. Nitrate isotope measurements provide a new constraint on the controls of surface nitrate concentration in this region and allow us to quantify the degree and temporal variability of nitrate consumption. Here we show that nitrate consumption in these waters cannot be fueled solely by the external supply of iron to these waters, which occurs by upwelling and dust deposition. Rather, a substantial fraction of nitrate consumption must be supported by the recycling of iron within surface waters. Given plausible iron recycling rates, seasonal variability in nitrate concentration on and off the equator can be explained by upwelling rate, with slower upwelling allowing for more cycles of iron regeneration and uptake. The efficiency of iron recycling in the equatorial Pacific implies the evolution of ecosystem-level mechanisms for retaining iron in surface ocean settings where it limits productivity. In the eastern equatorial Pacific, upwelling supplies nitrate in excess of iron relative to phytoplankton requirements. Here, using nitrate isotopes, the authors show that iron recycling in surface waters supports nitrate consumption, lowering surface nitrate concentration and explaining its variation.
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影响因子：
64.8
作者：
Coale, KH;Johnson, KS;Kudela, R
通讯作者：
Kudela, R
影响因子：
64.8
作者：
Barbeau, K;Rue, EL;Butler, A
通讯作者：
Butler, A
DOI：
10.1016/s0967-0645(98)00012-5
发表时间：
1998-01-01
影响因子：
3
作者：
Gordon, RM;Johnson, KS;Coale, KH
通讯作者：
Coale, KH
DOI：
10.1016/j.dsr.2009.12.008
发表时间：
2010-04-01
影响因子：
2.4
作者：
Gorgues, Thomas;Menkes, C.;Moulin, C.
通讯作者：
Moulin, C.
影响因子：
4.5
作者：
Granger, J;Sigman, DM;Harrison, PJ
通讯作者：
Harrison, PJ