Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia.
Sci Rep. 2013;3:2339. doi: 10.1038/srep02339.
Polar oceans are chemically sensitive to anthropogenic acidification due to their relatively low alkalinity and correspondingly weak carbonate buffering capacity. Here, we compare unique CO2 system observations covering complete annual cycles at an Arctic (Amundsen Gulf) and Antarctic site (Prydz Bay). The Arctic site experiences greater seasonal warming (10 vs 3°C), and freshening (3 vs 2), has lower alkalinity (2220 vs 2320 μmol/kg), and lower summer pH (8.15 vs 8.5), than the Antarctic site. Despite a larger uptake of inorganic carbon by summer photosynthesis, the Arctic carbon system exhibits smaller seasonal changes than the more alkaline Antarctic system. In addition, the excess surface nutrients in the Antarctic may allow mitigation of acidification, via CO2 removal by enhanced summer production driven by iron inputs from glacial and sea-ice melting. These differences suggest that the Arctic system is more vulnerable to anthropogenic change due to lower alkalinity, enhanced warming, and nutrient limitation.
极地海洋由于其相对较低的碱度和相应较弱的碳酸盐缓冲能力，对人为酸化非常敏感。在这里，我们比较了在北极（阿蒙森湾）和南极（普里兹湾）站点进行的独特的 CO2 系统观测，这些观测涵盖了完整的年周期。与南极站点相比，北极站点经历了更大的季节性升温（10 摄氏度对 3 摄氏度）和变咸（3 对 2），碱度更低（2220 对 2320 μmol/kg），夏季 pH 值更低（8.15 对 8.5）。尽管夏季光合作用吸收了更多的无机碳，但北极碳系统的季节性变化小于碱性更强的南极系统。此外，南极地区过剩的表面营养物质可能通过冰川和海冰融化带来的铁输入，促进夏季生产力的提高，从而去除 CO2，从而缓解酸化。这些差异表明，由于碱度较低、变暖加剧和营养限制，北极系统更容易受到人为变化的影响。
