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

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.