Feedbacks of CaCO3 dissolution effect on ocean carbon sink and seawater acidification: a model study
Feedbacks of CaCO3 dissolution effect on ocean carbon sink and seawater acidification: a model study
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DOI：
10.1088/2515-7620/aca9ac
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发表时间：
2022-12
影响因子：
2.9
通讯作者：
Han Zhang;Kuo Wang;Gaofeng Fan;Zhengquan Li;Zhenyan Yu;Jiu Jiang;Tao Lian;Guolin Feng
中科院分区：
文献类型：
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作者：
Han Zhang;Kuo Wang;Gaofeng Fan;Zhengquan Li;Zhenyan Yu;Jiu Jiang;Tao Lian;Guolin Feng
海洋对大气二氧化碳的吸收使海水酸化，从而加速钙化生物的碳酸钙溶解，这一过程被称为溶解效应。促进CaCO3溶解增加海水碱度，增强海洋碳汇，减缓海洋酸化。我们将CaCO3溶解和海洋酸化之间联系的不同参数纳入地球系统模型，以量化溶解效应对全球碳循环的反馈。在SRESA2二氧化碳排放情景及其在∼400年排放量为5000PGC的扩展情景下，在没有溶解效应的情况下，1800年至350年期间海洋CO2累积吸收为2041PGC。考虑溶解效应会使海洋碳汇增加195-858pGC(10%-42%)，并减缓表层pH下降0.04-0.17([H+](氢离子浓度)下降10%-48%)，具体取决于规定的参数化方案。在上层带，相对于弧-大西洋，太平洋-印度洋经历了更大的酸化，导致更大的溶解效应，从而对太平洋-印度洋的海洋碳汇和酸化产生更强的反馈。值得注意的是，溶解效应对海洋碳汇的反馈可以与CO2诱导的辐射增温反馈相当或更强。我们的研究突出了CaCO3溶解效应在海洋碳汇、全球碳循环和气候系统中潜在的关键作用。
The oceanic absorption of atmospheric CO2 acidifies seawater, which accelerates CaCO3 dissolution of calcifying organisms, a process termed dissolution effect. Promoted CaCO3 dissolution increases seawater ALK (alkalinity), enhancing ocean carbon sink and mitigating ocean acidification. We incorporate different parameterizations of the link between CaCO3 dissolution and ocean acidification into an Earth System Model, to quantify the feedback of the dissolution effect on the global carbon cycle. Under SRES A2 CO2 emission scenario and its extension with emissions of 5,000 PgC in ∼400 years, in the absence of the dissolution effect, accumulated ocean CO2 uptake between year 1800 and 3500 is 2,041 PgC. The consideration of the dissolution effect increases ocean carbon sink by 195–858 PgC (10%–42%), and mitigates the decrease in surface pH by 0.04–0.17 (a decrease of 10%–48% in [H+] (hydrogen ion concentration)), depending on the prescribed parameterization scheme. In the epipelagic zone, relative to the Arc-Atlantic Ocean, the Pacific-Indian Ocean experiences greater acidification, leading to greater dissolution effects and the resultant stronger feedbacks on ocean carbon sink and acidification in the Pacific-Indian Ocean. Noteworthy, the feedback of dissolution effect on ocean carbon sink can be comparable with or stronger than the feedback from CO2-induced radiative warming. Our study highlights the potentially critical role played by CaCO3 dissolution effect in the ocean carbon sink, global carbon cycle and climate system.