Effects of Snow and Remineralization Processes on Nutrient Distributions in Multi-Year Antarctic Landfast Sea Ice

We elucidated the effects of snow and remineralization processes on nutrient distributions in multi-year landfast sea ice (fast ice) in Lutzow-Holm Bay, East Antarctica. Based on sea-ice salinity, oxygen isotopic ratios, and thin section analyses, we found that the multi-year fast ice grew upward due to the year-by-year accumulation of snow. Compared to ice of seawater origin, nutrient concentrations in shallow fast ice were low due to replacement by clean and fresh snow. In deeper ice of seawater origin (the lower half of the multi-year fast ice column), remineralization was dominated by the degradation of organic matter. By comparison between first- and muti-year ice, the biological uptake and the remineralization were dominated in relatively young ice and older ice, respectively, under the physical process of brine drainage.

Automated summary

This study investigated the effects of snow and remineralization processes on nutrient distributions in multi-year landfast sea ice in Lutzow-Holm Bay, East Antarctica. It was found that the upward growth of the multi-year fast ice was attributed to the accumulation of snow over the years. Nutrient concentrations were lower in the shallow ice due to the replacement by clean and fresh snow, while remineralization dominated in the deeper ice from seawater origin. Additionally, the biological uptake was more dominant in relatively young ice, whereas older ice was more prone to remineralization under the physical process of brine drainage.