Gradients 4 - TN397 - Inorganic and Organic Nutrients and Particulates

These Simons Collaboration on Ocean Processes and Ecology (SCOPE) data products were produced by the University of Hawaiʻi at Mānoa with support from the Simons Foundation.

This dataset was collected on the R/V Thompson during the Gradients 4 cruise which departed from San Diego, CA and ended in Honolulu, HI. A transect was performed on the 140 degree longitude line from roughly 16 degrees N to 4 degrees S before heading to Honolulu. All organic and inorganic nutrients are analyzed in unflitered seawater that is sampled aboard from the CTD rosette into HDPE or polypropylene bottles and immediately frozen. Silicate, phosphate and nitrate+nitrite are determined colormetrically on a SEAL Analytical Autoanalyzer (AA3 with HR detectors), with the exception of nitrate+nitrite that is <0.5umol/L, which is analyzed by chemiluminescence. Total dissolved phosphorus (TDP) and total dissolved nitrogen (TDN) are determined by analysis of phosphate and nitrate, respectively, after oxidation by high-intensity ultraviolet light. Dissolved organic phosphorus and dissolved organic nitrogen are determined by subtracting background PO4 and NO3+NO2+NH4 from TDP and TDN, respectively. Note, because samples are not filtered particulates may comprise a minor portion of totals. Time is in UTC. Details on the methods for particulates (PC, PN, PP, PATP) are available at: https://hahana.soest.hawaii.edu/hot/methods/results.html.

西蒙斯海洋过程与生态合作研究（Simons Collaboration on Ocean Processes and Ecology, SCOPE）的这批数据产品由夏威夷大学马诺阿分校制作，获得西蒙斯基金会资助。

本数据集采集自汤普森号科考船（R/V Thompson）执行的“梯度4号”（Gradients 4）科考航次，该航次从加利福尼亚州圣迭戈出发，最终抵达夏威夷州火奴鲁鲁。航次作业期间，科研团队先沿140°经线完成了从约16°N至4°S的断面观测，随后前往火奴鲁鲁。所有有机与无机营养盐样品均取自未过滤的海水：利用温盐深采水器（CTD rosette）采集海水至高密度聚乙烯（HDPE）或聚丙烯（polypropylene）瓶中，并立即进行冷冻保存。

硅酸盐、磷酸盐以及硝酸盐+亚硝酸盐采用比色法在SEAL Analytical Autoanalyzer（搭载高分辨率检测器的AA3型自动分析仪）上完成测定，其中浓度低于0.5 μmol/L的硝酸盐+亚硝酸盐样品采用化学发光法分析。总溶解磷（TDP）与总溶解氮（TDN）分别通过高强度紫外光氧化后，测定对应的磷酸盐与硝酸盐含量计算得到。溶解态有机磷（Dissolved organic phosphorus, DOP）与溶解态有机氮（Dissolved organic nitrogen, DON）则分别通过总溶解磷、总溶解氮扣除背景态的PO₄与NO₃+NO₂+NH₄含量推导得出。请注意，由于未对样品进行过滤，颗粒物可能会在总测定含量中占据微小比例。时间采用协调世界时（UTC）。颗粒物（PC、PN、PP、PATP）的分析方法细节可参见：https://hahana.soest.hawaii.edu/hot/methods/results.html。