Seasonal full-depth dissolved inorganic carbon (DIC), total alkalinity (TA), pH, and aragonite saturation state (Ωarag) at nine stations across the Florida Straits at 27°N from 2002 to 2018 (NCEI Accession 0244859)

This dataset contains full-depth carbonate chemistry profile data at the seasonal frequency of ship-based hydrographic surveys for the Florida Straits at 27°N from 2002 to 2018. We firstly developed an algorithm to estimate subsurface (~50 m) dissolved inorganic carbon (DIC) using measured data from carbonate chemistry-focused research cruise surveys across the Florida Straits at 27°N. This algorithm was then applied to the long-term non-carbonate chemistry time-series dataset to generate a DIC record. Total alkalinity of the full water column was estimated from a linear relationship with salinity based on measured data from carbonate chemistry focused research cruise surveys across the Florida Straits at 27°N. Furthermore, subsurface pH and aragonite saturation state (Ωarag) were calculated from DIC and TA using CO2SYS (Van Heuven et al., 2009) with the first and second carbonic acid dissociation constants K1 and K2 from Lueker et al. (2000), the acidity constant of the ion HSO4- from Dickson (1990), and borate-to-salinity ratio from Lee et al. (2010). For surface mixed layer (<50 m), DIC, pH, and (Ωarag) were calculated from TA and fCO2, where the latter was calculated using algorithms provided by Wanninkhof et al. (2020) based on the observational data from the Atlantic Oceanographic and Meteorological Laboratory (AOML) Ship of Opportunity-CO2 (SOOP-CO2) program from Royal Caribbean international cruise ships.

本数据集涵盖2002年至2018年间，北纬27°佛罗里达海峡的船舶水文调查以季节频次获取的全深度碳酸盐化学剖面数据。本研究首先开发了一种算法，基于北纬27°佛罗里达海峡碳酸盐化学专项科考航次的实测数据，估算次表层（约50米深度）的溶解无机碳（dissolved inorganic carbon, DIC）。随后将该算法应用于长期非碳酸盐化学时间序列数据集，以生成DIC记录。基于北纬27°佛罗里达海峡碳酸盐化学专项科考航次的实测数据，通过与盐度的线性关系估算全水柱总碱度（total alkalinity, TA）。此外，次表层pH及文石饱和状态（aragonite saturation state, Ωarag）通过CO2SYS软件（Van Heuven等，2009）计算得到，计算时采用了Lueker等（2000）提出的碳酸第一、二级解离常数K1和K2、Dickson（1990）给出的硫酸氢根离子（HSO₄⁻）酸度常数，以及Lee等（2010）的盐度-硼酸盐比值关系，输入参数为DIC与总碱度。对于表层混合层（深度<50米），其DIC、pH及Ωarag由总碱度与表层二氧化碳分压（fCO₂）计算得到；其中fCO₂基于皇家加勒比国际（Royal Caribbean International）邮轮的大西洋海洋与气象实验室（Atlantic Oceanographic and Meteorological Laboratory, AOML）船舶走航CO₂（Ship of Opportunity-CO2, SOOP-CO2）项目的观测数据，采用Wanninkhof等（2020）提供的算法计算得出。