Multi-tracer study on Arctic Ocean Acidification

我们观测了加拿大盆地碳酸钙饱和态的分布。表层和次表层均存在不饱和水。地表不饱和水的分布主要受稀释、增温/降温和光合作用的影响。对于次表层不饱和水(太平洋冬季水)，我们测量了SF6浓度，以估算水团年龄。结果表明，加拿大盆地的PWW的平均年龄为~10年，较新的PWW通过3条路径输送到盆地。我们还开发了一种根据盐度、温度和氧气数据重建碳酸钙饱和状态的方法。重建值与观测值吻合较好。将这种方法应用于历史观测，可以绘制出整个北冰洋的碳酸钙饱和状态图。此外，我们还利用系泊水样采样器成功地采集了全年的海水样本。

We have observed distribution of calcium carbonate saturation state in the Canada Basin. Undersaturated waters were found at the surface and subsurface layers. The distributions of surface undersaturated water were mainly determined by dilution, warming/cooling and photosynthesis. For the subsurface undersaturated water (Pacific Winter Water), we have measured SF6 concentrations in order to estimate water mass ages. Results revealed that mean age of PWW in the Canada Basin is ~10 years and newer PWW is transported in to the basen by 3 pathways. We also developed a method to reconstruct calcium carbonate saturation state from salinity, temperature and oxygen data. Reconstructed values well agreed with observed values. By applying this method to historical observations, we could make a map of calcium carbonate saturation state for the entire Arctic Ocean.Furthermore, we have successfully collected seawater samples throughout the year, by using moored water samplers.