Impact of sea-ice processes on the carbonate system and ocean acidification at the ice-water interface of the Amundsen Gulf, Arctic Ocean
Impact of sea-ice processes on the carbonate system and ocean acidification at the ice-water interface of the Amundsen Gulf, Arctic Ocean
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DOI：
10.1002/2013jc009164
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发表时间：
2013-12-01
影响因子：
3.6
通讯作者：
Papakyriakou, Tim N.
中科院分区：
文献类型：
--
作者：
Fransson, Agneta;Chierici, Melissa;Papakyriakou, Tim N.
从2007年11月海冰形成到2008年5月海冰开始融化，我们研究了北极海冰第一年的碳酸盐系统，重点研究了文石（Ar）和方解石（Ca）在冰-水界面（uw）的碳酸钙（CaCO3）饱和状态的影响。基于总无机碳（C-T）和总碱度（A(T)），以及推导出的pH、CO2、碳酸盐离子（[CO32-]）浓度，研究了海冰、盐水、霜花和uw中卤水排斥、CaCO3沉淀、细菌呼吸、初级生产和CO2-气体通量等主要驱动因素。我们估计海冰C-T在顶部、中部和底部的变化很大。3 - 5月，CaCO3和CO2-gas通量变化对整个冰芯C-T的影响较大，底部冰的细菌呼吸作用在所有月份都很重要，5月是主要生产季节。显然，海冰过程对uw的影响较大，导致碳酸盐系统的季节振幅相对于20 m以上增大了5倍。在冰形成过程中，[CO2]增加了30 mu mol kg(-1)， [CO32-]减少了50 mu mol kg(-1)， uw中的Ar降低了0.8。相反，在冰融化期间，uw的[CO32-]增加了90 mu mol kg(-1)， 3月至5月期间增加了1.4 mu mol kg(-1)，可能是由于CaCO3溶解和初级生产。我们估计，冰融化的增加将导致海洋对表层无机碳的吸收增加。
From sea-ice formation in November 2007 to onset of ice melt in May 2008, we studied the carbonate system in first-year Arctic sea ice, focusing on the impact of calcium-carbonate (CaCO3) saturation states of aragonite (Ar) and calcite (Ca) at the ice-water interface (UIW). Based on total inorganic carbon (C-T) and total alkalinity (A(T)), and derived pH, CO2, carbonate ion ([CO32-]) concentrations and , we investigated the major drivers such as brine rejection, CaCO3 precipitation, bacterial respiration, primary production and CO2-gas flux in sea ice, brine, frost flowers and UIW. We estimated large variability in sea-ice C-T at the top, mid, and bottom ice. Changes due to CaCO3 and CO2-gas flux had large impact on C-T in the whole ice core from March to May, bacterial respiration was important at the bottom ice during all months, and primary production in May. It was evident that the sea-ice processes had large impact on UIW, resulting in a five times larger seasonal amplitude of the carbonate system, relative to the upper 20 m. During ice formation, [CO2] increased by 30 mu mol kg(-1), [CO32-] decreased by 50 mu mol kg(-1), and the Ar decreased by 0.8 in the UIW due to CO2-enriched brine from solid CaCO3. Conversely, during ice melt, [CO32-] increased by 90 mu mol kg(-1) in the UIW, and increased by 1.4 between March and May, likely due to CaCO3 dissolution and primary production. We estimated that increased ice melt would lead to enhanced oceanic uptake of inorganic carbon to the surface layer.