Key controls on the seasonal and interannual variations of the carbonate system and air-sea CO2 flux in the Northeast Atlantic (Bay of Biscay)
Key controls on the seasonal and interannual variations of the carbonate system and air-sea CO2 flux in the Northeast Atlantic (Bay of Biscay)
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DOI：
10.1002/jgrc.20087
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发表时间：
2013-02
期刊：
影响因子：
1.7
通讯作者：
Zong‐Pei Jiang;D. Hydes;T. Tyrrell;S. Hartman;M. Hartman;C. Dumousseaud;X. A. Padin;I. Skjelvan;C. González-Pola
中科院分区：
文献类型：
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作者：
Zong‐Pei Jiang;D. Hydes;T. Tyrrell;S. Hartman;M. Hartman;C. Dumousseaud;X. A. Padin;I. Skjelvan;C. González-Pola
[1]对东北大西洋(比斯开湾)地表水的生物地球化学变化进行了研究，采用高频在航测量和每月碳相关变量采样相结合的方法。通过区分生物过程和物理过程对溶解无机碳(DIC)和二氧化碳分压(PCO2)月变化的贡献，探讨了控制CO2季节变化的机制。DIC(47-81µm o l kg−1)的季节变化呈单峰型，冬季最大值主要由垂直混合驱动，夏季最低值主要由春季生物去除驱动。非红场C：N吸收在营养耗竭的夏季观察到，但在春季开花期间没有观察到。在北大西洋，二氧化碳的季节变化表现出纬向的转变：从温度主导的少营养副热带环流到亚极区，在那里二氧化碳由变化的DIC浓度主导。在中纬度的比斯开湾，二氧化碳的年周期(61-75微米)呈双峰分布。夏季CO2峰值主要受气温升高的影响，冬季峰值主要受地下水夹带作用的影响。DIC的年际变化在冬季更为明显，并且是由冬季混合强度的变化驱动的。当混合层深度较深时，冬季DIC的浓度和季节幅度较高，这似乎与北大西洋涛动的负相位有关。比斯开湾2008年至2010年的二氧化碳吸收(−0.97和−0.75molm−2年−1)较2002年至2004年(−1.47和−1.68molm−2年−1)有所下降。
[1] Biogeochemical variations of surface water in the Northeast Atlantic (Bay of Biscay) were examined using high-frequency underway measurements combined with monthly sampling of carbon-related variables. The mechanisms controlling seasonal CO2 variability were investigated by distinguishing the contributions of biological and physical processes to the monthly changes in dissolved inorganic carbon (DIC) and partial pressure of CO2 (pCO2). The seasonality of DIC (47–81 µmol kg−1) had a single peak with a winter maximum primarily driven by vertical mixing and a summer minimum driven by spring biological removal. Non-Redfield C:N uptake was observed in the nutrient-depleted summer but not during the spring bloom. In the North Atlantic, pCO2 seasonality shows a latitudinal transition: from the temperature-dominated oligotrophic subtropical gyre to the subpolar region where pCO2 is dominated by changing concentrations of DIC. In the midlatitude Bay of Biscay, the annual cycle of pCO2 (61–75 µatm) showed a double-peak distribution. The summer pCO2 peak was mainly driven by temperature increase, while the winter peak resulted from the dominant effect of entrainment of subsurface water. Interannual variations of DIC were more pronounced in winter and were driven by the changes in the strength of winter mixing. Higher wintertime concentrations and seasonal amplitudes of DIC were observed in cold years when the mixed-layer depths were deeper, which appears to be associated with negative phases of the North Atlantic Oscillation. The Bay of Biscay shows a decrease of CO2 uptake in 2008–2010 (−0.97 and −0.75 mol m−2 yr−1) compared to 2002–2004 (−1.47 and −1.68 mol m−2 yr−1).