Influence of glacial water and carbonate minerals on wintertime sea-ice biogeochemistry and the CO2 system in an Arctic fjord in Svalbard
Influence of glacial water and carbonate minerals on wintertime sea-ice biogeochemistry and the CO2 system in an Arctic fjord in Svalbard
复制标题
冰川水和碳酸盐矿物对斯瓦尔巴群岛北极峡湾冬季海冰生物地球化学和二氧化碳系统的影响
DOI：
10.1017/aog.2020.52
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发表时间：
2020
影响因子：
2.9
通讯作者：
Nehrke Gernot
中科院分区：
文献类型：
--
作者：
Fransson Agneta;Chierici Melissa;Nomura Daiki;Granskog Mats A.;Kristiansen Svein;Martma Tonu;Nehrke Gernot
淡水资源对冬季海冰CO2过程的影响进行了研究，从冰川前沿到斯瓦尔巴特群岛的Tempelfjorden，海冰，冰川冰，盐水和雪。2012年3月至4月天气温和，峡湾主要被流冰覆盖，而2013年4月天气较冷，观测到的快冰较厚。这导致海冰和冰下水的物理和化学性质不同。来自稳定氧同位素比率和盐度的数据显示，2012年4月冰川前沿的海冰平均含有54%的冰川融水。这比2013年4月高出五倍，当时冰是冻结的海水。2012年4月，海冰总碱度（AT）、碳酸根离子（[CO32−]）和碳酸氢根离子（[HCO3−]）相对于盐度的最大过量主要与富含矿物质的冰川水冻结过程中溶解的白云石和方解石有关。2013年4月，这些变量过多的主要原因是海冰过程导致的伊卡特溶解。白云岩溶解增加海冰的两倍多的ikaite和方解石溶解，这意味着不同的缓冲能力和潜力的海洋CO2吸收在不断变化的气候。
The effect of freshwater sources on wintertime sea-ice CO2 processes was studied from the glacier front to the outer Tempelfjorden, Svalbard, in sea ice, glacier ice, brine and snow. March–April 2012 was mild, and the fjord was mainly covered with drift ice, in contrast to the observed thicker fast ice in the colder April 2013. This resulted in different physical and chemical properties of the sea ice and under-ice water. Data from stable oxygen isotopic ratios and salinity showed that the sea ice at the glacier front in April 2012 contained on average 54% of frozen-in glacial meltwater. This was five times higher than in April 2013, where the ice was frozen seawater. In April 2012, the largest excess of sea-ice total alkalinity (AT), carbonate ion ([CO32−]) and bicarbonate ion concentrations ([HCO3−]) relative to salinity was mainly related to dissolved dolomite and calcite incorporated during freezing of mineral-enriched glacial water. In April 2013, the excess of these variables was mainly due to ikaite dissolution as a result of sea-ice processes. Dolomite dissolution increased sea-ice AT twice as much as ikaite and calcite dissolution, implying different buffering capacity and potential for ocean CO2 uptake in a changing climate.