Ocean Acidification: Present Conditions and Future Changes in a High-CO2 World
Ocean Acidification: Present Conditions and Future Changes in a High-CO2 World
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DOI：
10.5670/oceanog.2009.95
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发表时间：
2009-12-01
期刊：
影响因子：
2.8
通讯作者：
Cooley, Sarah R.
中科院分区：
文献类型：
--
作者：
Feely, Richard A.;Doney, Scott C.;Cooley, Sarah R.
全球海洋对人为CO的吸收引起海水化学的根本变化，可能对上层海洋的生物生态系统产生巨大影响。根据政府间气候变化专门委员会（气专委）的“一切照旧”排放情景所作的估计表明，大气中的二氧化碳水平在世纪末可能接近百万分之800。相应的海洋生物地球化学模型表明，到本世纪末，地表水pH值将从工业化前的约8.2下降到IPCC A2情景中的约7.8，相对于工业时代的开始，海洋的酸度增加了约150%。在当代海水中，CO2浓度升高也将导致地表水碳酸盐离子浓度大幅降低，无论是绝对变化还是相对于工业化前水平的分数变化。对于大多数开放的海洋表面沃茨，文石欠饱和发生时，碳酸根离子浓度下降到约66 μ mol kg（-1）以下。模型预测表明，文石不饱和将于2020年左右开始出现在北冰洋，2050年在南大洋。到2050年，整个北极地区的文石都将不饱和，到2095年，整个南大洋和北太平洋的部分地区都将不饱和。对于方解石，当碳酸根离子浓度降到42 μ mol kg（-1）以下时，就会发生欠饱和。到2095年，北极的大部分地区以及白令海和楚科奇海的一些地区将出现方解石不饱和现象。然而，在大多数其他海洋盆地中，表面沃茨中的方解石仍将是饱和的，但其含量比目前大大降低。
The uptake of anthropogenic CO, by the global ocean induces fundamental changes in seawater chemistry that could have dramatic impacts on biological ecosystems in the upper ocean. Estimates based on the Intergovernmental Panel on Climate Change (IPCC) business-as-usual emission scenarios suggest that atmospheric CO2 levels could approach 800 ppm near the end of the century. Corresponding biogeochemical models for the ocean indicate that surface water pH will drop from a pre-industrial value of about 8.2 to about 7.8 in the IPCC A2 scenario by the end of this century, increasing the ocean's acidity by about 150% relative to the beginning of the industrial era. In contemporary ocean water, elevated CO2 will also cause substantial reductions in surface water carbonate ion concentrations, in terms of either absolute changes or fractional changes relative to pre-industrial levels. For most open-ocean surface waters, aragonite undersaturation occurs when carbonate ion concentrations drop below approximately 66 mu mol kg(-1). The model projections indicate that aragonite undersaturation will start to occur by about 2020 in the Arctic Ocean and 2050 in the Southern Ocean. By 2050, all of the Arctic will be undersaturated with respect to aragonite, and by 2095, all of the Southern Ocean and parts of the North Pacific will be undersaturated. For calcite, undersaturation occurs when carbonate ion concentration drops below 42 mu mol kg(-1). By 2095, most of the Arctic and some parts of the Bering and Chukchi seas will be undersaturated with respect to calcite. However, in most of the other ocean basins, the surface waters will still be saturated with respect to calcite, but at a level greatly reduced from the present.