Seasonally different carbon flux changes in the Southern Ocean in response to the southern annular mode.
Seasonally different carbon flux changes in the Southern Ocean in response to the southern annular mode.
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DOI：
10.1002/2013gb004600
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发表时间：
2013-12
影响因子：
5.2
通讯作者：
Wolf-Gladrow, D. A.
中科院分区：
文献类型：
--
作者：
Hauck, J.;Voelker, C.;Wang, T.;Hoppema, M.;Losch, M.;Wolf-Gladrow, D. A.
平流层臭氧消耗和温室气体排放导致南环模（SAM）趋向于高指数极性。 SAM 正相位的特点是西风比平常更强，导致物理碳传输发生变化。通过耦合生态系统-总体环流模型和回归分析，探讨了南大洋上层 100 m 自然碳收支因 SAM 正相而发生的变化。以前被忽视的过程在正 SAM 期间对上层海洋碳预算很重要，即极锋 (PF) 北部的碳输出和向下输送与南部的上升流一样大。有限的微量营养素铁通过上升流带入表层，刺激浮游植物生长和出口生产，但仅限于夏季。这会减少碳排放，并减少夏季自然二氧化碳的排出（或更多吸收）。在冬季，生物机制不活跃，表层海洋通过释放二氧化碳与大气保持平衡。从年平均值来看，PF以南的上层海洋区域因额外的出口生产而损失的碳多于向大气中释放二氧化碳的损失，这凸显了生物碳泵在应对积极的SAM事件中的作用。
Stratospheric ozone depletion and emission of greenhouse gases lead to a trend of the southern annular mode (SAM) toward its high-index polarity. The positive phase of the SAM is characterized by stronger than usual westerly winds that induce changes in the physical carbon transport. Changes in the natural carbon budget of the upper 100 m of the Southern Ocean in response to a positive SAM phase are explored with a coupled ecosystem-general circulation model and regression analysis. Previously overlooked processes that are important for the upper ocean carbon budget during a positive SAM period are identified, namely, export production and downward transport of carbon north of the polar front (PF) as large as the upwelling in the south. The limiting micronutrient iron is brought into the surface layer by upwelling and stimulates phytoplankton growth and export production but only in summer. This leads to a drawdown of carbon and less summertime outgassing (or more uptake) of natural CO2. In winter, biological mechanisms are inactive, and the surface ocean equilibrates with the atmosphere by releasing CO2. In the annual mean, the upper ocean region south of the PF loses more carbon by additional export production than by the release of CO2 into the atmosphere, highlighting the role of the biological carbon pump in response to a positive SAM event.