nECS OA_Figshare.xlsx

Measurements were taken during four seasonal cruises of the R/V <i>Onnuri</i> in spring (May 15–21) 2017, summer (August 16–23) 2016, autumn (November 6–15) 2015, and winter (February 8–14) 2017. Depth profiles of temperature and salinity were measured using a calibrated conductivity–temperature–depth/pressure (CTD) recorder (SBE 911; Sea-Bird Electronics Inc., Bellevue, WA, USA). Seawater samples were collected using a rosette sampler with 10 L Niskin bottles mounted onto the CTD assembly at eight depths (0, 10, 20, 30, 50, 75, 100, and 150 m) for each station in both transects F (33 °N) and H (32 °N). We could not conduct winter survey in H transect. Dissolved Inorganic Carbon (DIC), total alkalinity (TA), and nutrients (phosphate and silicate) were analyzed under laboratory conditions. Bottom seawater samples were collected 5 m above the bottom at stations where the depth was less than 100 m.The DIC was measured by acid extraction with infrared CO₂ detection (AS-C3, Apollo SciTech Inc., USA), and the TA was determined by open-cell Gran acidimetric titration (AS-ALK2, Apollo SciTech Inc., USA). The uncertainties of measurements were evaluated daily using certified reference materials for seawater provided by the Scripps Institution of Oceanography (San Diego, USA). The DIC and TA measurements had precisions of approximately ±1.5 and ±2 μmol kg^–¹, respectively. The seawater CaCO₃ saturation state for aragonite (Ωarag) was calculated with CO2SYS program version 2.1 using salinity, temperature, depth, phosphate, silicate, TA, and DIC data. The carbonic acid dissociation constants of Mehrbach et al. (1973), as refit by Dickson and Millero (1987), were used to determine Ωarag. The uncertainty in the estimation of Ωarag was approximately ±0.02.<br>本数据集的测量数据采集自“Onnuri”号调查船的4个季节航次：2017年春季（5月15日—21日）、2016年夏季（8月16日—23日）、2015年秋季（11月6日—15日）以及2017年冬季（2月8日—14日）。采用经过校准的温盐深/压力（conductivity-temperature-depth/pressure, CTD）记录仪（型号SBE 911，产自美国华盛顿州贝尔维尤市海鸟电子公司（Sea-Bird Electronics Inc.））测定温度和盐度的垂直剖面数据。借助安装于CTD组件上的10升尼斯金（Niskin）采水瓶组成的多瓶采水器架，在F断面（33°N）和H断面（32°N）的每个站位的8个深度层（0、10、20、30、50、75、100和150米）采集海水样品。但H断面未开展冬季航次调查。溶解无机碳（Dissolved Inorganic Carbon, DIC）、总碱度（Total Alkalinity, TA）以及营养盐（磷酸盐和硅酸盐）均在实验室环境下完成分析。对于水深不足100米的站位，在距海底5米处采集底层海水样品。溶解无机碳采用酸萃取-红外CO₂检测法（型号AS-C3，美国阿波罗科技公司（Apollo SciTech Inc.））测定，总碱度采用开放式池Gran酸滴定法（型号AS-ALK2，美国阿波罗科技公司）测定。每日采用美国圣迭戈斯克里普斯海洋研究所（Scripps Institution of Oceanography）提供的海水标准参考物质评估测量不确定度。溶解无机碳和总碱度的测量精密度分别约为±1.5 μmol·kg⁻¹和±2 μmol·kg⁻¹。利用盐度、温度、水深、磷酸盐、硅酸盐、总碱度及溶解无机碳数据，通过CO2SYS 2.1版本程序计算海水文石碳酸钙饱和状态（Ωarag）。计算过程中采用经Dickson与Millero（1987）修正的Mehrbach等（1973）碳酸解离常数，文石饱和状态估算的不确定度约为±0.02。