Hydrochemistry measured on water bottle samples in the northern Benguela during SONNE cruise SO283@en

We present data on distribution of inorganic nitrogen compounds i.e. nitrate, nitrite and ammonium, and also phosphate and silicate in the northern Benguela and the Angola-Benguela Front regions. The fieldwork took place during the cruise No. SO283 (March 19st - May 25st, 2021) onboard the R/V SONNE, which encompassed close-coastal and open ocean regions off Angola, Namibia and South Africa. All nutrient samples were retrieved with the ship's CTD rosette (SBE 9+). Immediately after sampling, a volume of about 40 ml of each sample was filtered through a disposable syringe filter (CA, 0.45 µm) and filled in a pre-rinsed 50 ml PE bottle. The bottles were securely closed and kept frozen at -20°C until further analysis. The concentrations of nutrients were determined colorimetrically after Grasshoff et al. (1999) using segmented flow analyzer (QuAAtro AutoAnalyzer, Seal Analytical) in the laboratory at IOW. For the quality control, a reference standard was also measured at regular intervals.本数据集提供了本格拉海盆北部以及安哥拉-本格拉锋面（Angola-Benguela Front）区域内无机氮化合物（即硝酸盐、亚硝酸盐与铵态氮）、磷酸盐及硅酸盐的分布数据。本次野外作业依托SONNE号科考调查船（R/V SONNE）的SO283号航次开展，作业时段为2021年3月19日至5月25日，覆盖安哥拉、纳米比亚及南非沿岸的近岸与远洋海域。所有营养盐样品均通过船载CTD采水器阵列（CTD rosette，型号SBE 9+）采集。采样完成后立即将每份约40 mL的样品经一次性针式过滤器（CA，0.45 μm）过滤，随后装入经预冲洗的50 mL聚乙烯（PE）样品瓶中。样品瓶密封后置于-20℃条件下冷冻保存，以待后续分析。营养盐浓度依照Grasshoff等（1999）提出的分析方法，采用分段流动分析仪（QuAAtro全自动化学分析仪，Seal Analytical生产），于基尔海洋研究所（IOW）实验室中通过比色法完成测定。为保障分析质量，实验过程中定期插入标准参考物质进行校准。