Polar and Marine Research Institute, Jimei University, Xiamen, 361000, China.
Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361000, China.
Mar Environ Res. 2023 Sep;190:106083. doi: 10.1016/j.marenvres.2023.106083. Epub 2023 Jul 5.
The carbonate chemistry of sea ice plays a critical role in global ocean carbon cycles, particularly in polar regions which are subject to significant climate change-induced sea ice variation. However, less is known about the interaction of carbonate system between sea ice and its adjacent seawaters due to sparse sampling and disparities in reported results. Here we provide an insight into this issue by collecting and measuring dissolved inorganic carbon (DIC) and associated environmental parameters in Arctic sea ice during a cruise in the summer of 2014. Our observations show that DIC in Arctic summer sea ice has a mean concentration of 463.3 ± 213.0 μmol/kg and appears to be controlled mainly by the fraction of brine water in the ice. The low Chl a and nutrients content in sea ice indicate minor contribution of biological uptake to sea-ice DIC in the western Arctic Ocean. The DIC concentration in surface water (<100 m depth) decreased from a mean of 2108.3 ± 45.4 μmol/kg in 1994 to a mean of 2052.4 ± 98.6 μmol/kg in 2014, due to the enhanced sea ice melting that dilutes the DIC concentrations of surrounding seawaters.
海冰的碳酸盐化学在全球海洋碳循环中起着至关重要的作用，特别是在极地地区，这些地区受到气候变化引起的海冰变化的显著影响。然而，由于采样稀疏和报告结果的差异，人们对海冰与其相邻海水之间的碳酸盐系统相互作用了解较少。在这里，我们通过在 2014 年夏季的一次航行中收集和测量北极海冰中的溶解无机碳（DIC）和相关环境参数，深入了解了这一问题。我们的观测结果表明，北极夏季海冰中的 DIC 平均浓度为 463.3±213.0 μmol/kg，似乎主要受冰中盐水部分的控制。海冰中低叶绿素 a 和营养物质含量表明，生物吸收对西北冰洋海冰 DIC 的贡献较小。由于海冰融化增强，周围海水的 DIC 浓度被稀释，1994 年至 2014 年间，<100 m 水深的表层海水的 DIC 浓度从平均 2108.3±45.4 μmol/kg 降至平均 2052.4±98.6 μmol/kg。
