Seasonal calcium carbonate undersaturation in shelf waters of the Western Arctic Ocean; how biological processes exacerbate the impact of ocean acidification
Seasonal calcium carbonate undersaturation in shelf waters of the Western Arctic Ocean; how biological processes exacerbate the impact of ocean acidification
复制标题
北冰洋西部陆架水域的季节性碳酸钙欠饱和；生物过程如何加剧海洋酸化的影响；
DOI：
10.5194/bgd-9-14255-2012
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发表时间：
2014
影响因子：
--
通讯作者：
J. Mathis
中科院分区：
文献类型：
--
作者：
N. Bates;M. Orchowska;R. Garley;J. Mathis
北冰洋仅占全球海洋面积的4%，但却对全球碳循环做出了重大贡献。最近对 2009 年至 2011 年北极西部陆架水域海水碳酸盐化学的观察表明，大面积的底栖生物暴露于碳酸钙 (CaCO 3 ) 矿物（特别是文石）季节性欠饱和的底部水域。我们的观察表明，北极西部地下的方解石 (Ω 方解石 ) 和霰石 (Ω 文石 ) 的饱和状态 ( Ω ) 分别随季节减少 0.9 和 0.6。这些数据表明，每年有 10 个月的时间里，北极西部陆架的底层水已经对生物和沉积 CaCO 3 具有潜在的腐蚀性。 Ω 的季节性变化是由多种因素造成的，例如浮游植物的光合作用、有机物的呼吸/再矿化以及 CO 2 的气海气体交换——这些过程的结合分别会增加或增强地表和地下水中的 Ω。这些季节性物理和生物过程还可以分别减轻或增强人类世海洋 15 酸化 (OA) 对地表和地下水中 Ω 的影响。未来对北极西部陆架的监测有必要评估海洋酸化和季节性生物/物理过程对北极海洋生态系统当前和未来对Ω值的影响。
The Arctic Ocean accounts for only 4 % of the global ocean area but it contributes significantly to the global carbon cycle. Recent observations of seawater carbonate chemistry in shelf waters of the Western Arctic from 2009 to 2011 indicate that extensive areas of the benthos are exposed to bottom waters that are seasonally undersatu- 5 rated with respect to calcium carbonate (CaCO 3 ) minerals, particularly aragonite. Our observations indicate seasonal reduction of saturation states ( Ω ) for calcite ( Ω calcite ) and aragonite ( Ω aragonite ) in the subsurface in the Western Arctic by as much as 0.9 and 0.6, respectively. Such data indicates that bottom waters of the Western Arctic shelves are already potentially corrosive for biogenic and sedimentary CaCO 3 for sev- 10 eral months each year. Seasonal changes in Ω are imparted by a variety of factors such as phytoplankton photosynthesis, respiration/remineralization of organic matter and air-sea gas exchange of CO 2 – combined these processes either increase or enhance Ω in surface and subsurface waters, respectively. These seasonal physical and biological processes also act to mitigate or enhance the impact of Anthropocene ocean 15 acidification (OA) on Ω in surface and subsurface waters, respectively. Future monitoring of the Western Arctic shelves is warranted to assess the present and future impact on Ω values from ocean acidification and seasonal biological/physical processes on Arctic marine ecosystems.