antFOCE Seawater Carbonate Chemistry collected at Casey Station in the 2014/2015 season.

Carbonate chemistry data for the antFOCE seawater samples. The download file contains an Excel spreadsheet with a number of worksheets detailing the samples collected from O'Brien Bay, Casey Station. The dataset includes information on oxygen levels, pH levels, temperature and salinity levels, as well as the concentrations of various elements (dissolved inorganic carbon, phosphate, nitrate, nitrite, silicate).Free-ocean CO2 enrichment (FOCE) experiments have been deployed in marine ecosystems to manipulate carbonate system conditions to those predicted in future oceans. We investigated whether the pH/carbonate chemistry of extremely cold polar waters can be manipulated in an ecologically relevant way, to represent conditions under future atmospheric CO2 levels, in an in-situ FOCE experiment in Antarctica. We examined spatial and temporal variation in local ambient carbonate chemistry at hourly intervals at two sites between December and February and compared these with experimental conditions. We successfully maintained a mean pH offset in acidified benthic chambers of -0.38 (plus or minus 0.07) from ambient for approximately 8 weeks. Local diel and seasonal fluctuations in ambient pH were duplicated in the FOCE system. Large temporal variability in acidified chambers resulted from system stoppages. The mean pH, Ωarag and fCO2 values in the acidified chambers were 7.688 plus or minus 0.079, 0.62 plus or minus 0.13 and 912 plus or minus 150 micro-atm respectively. Variation in ambient pH appeared to be mainly driven by salinity and biological production and ranged from 8.019 to 8.192 with significant spatio-temporal variation. This experiment demonstrates the utility of FOCE systems to create conditions expected in future oceans that represent ecologically relevant variation, even under polar conditions.

antFOCE海水样品的碳酸盐化学数据。
下载文件包含一份Excel电子表格，内含多张工作表，详细记录了从凯西站奥布莱恩湾采集的样品相关信息。本数据集涵盖溶氧浓度、pH值、温度及盐度数据，同时包含多种元素的浓度信息，即溶解无机碳（dissolved inorganic carbon）、磷酸盐（phosphate）、硝酸盐（nitrate）、亚硝酸盐（nitrite）与硅酸盐（silicate）。
游离海洋CO₂富集（Free-ocean CO₂ enrichment, FOCE）实验已被应用于海洋生态系统，用于调控碳酸盐系统条件，使其匹配未来海洋的预测状态。我们借助南极的原位FOCE实验，探究了极寒极地海水的pH值与碳酸盐化学特征能否以符合生态相关性的方式进行调控，以模拟未来大气CO₂浓度下的海洋环境。我们于12月至次年2月期间，在两个采样点以小时为间隔监测了当地原位碳酸盐化学特征的时空变化，并将其与实验条件进行对比。我们成功在酸化底栖舱内维持了约8周的平均pH偏移量，即较原位环境低0.38±0.07。FOCE系统成功复现了原位环境pH的昼夜与季节波动。酸化舱内出现的大幅时间变异源于实验系统的停机事件。酸化舱内的平均pH值、文石饱和指数（Ωarag）及CO₂分压（fCO₂）分别为7.688±0.079、0.62±0.13及912±150 μatm。原位pH的变化范围为8.019至8.192，且存在显著的时空变异，其变化主要受盐度与生物生产活动调控。本实验证明，即便在极地环境下，FOCE系统仍可用于构建符合未来海洋预期状态且具备生态相关性的实验环境。