Hydrochemistry measured on water bottle samples during the cruise Hai Yang Di Zhi Shi Hao in South China Sea in September 2018

During the cruise H10-2018 on board the Chinese R/V Hai Yang Di Zhi Shi Hao, we collected water with a CTD SBE911 rosette system in 64 stations distributed along the shelf, shelf edge and deep-sea of the northern South China Sea. We aimed to study the nutrients availability and primary production distribution under the influence of the strong typhoon Mangkhut, in September 2018. The influence of the Mangkhut typhoon over the upper 100 m of the water column was accessed before and after its passage. The physical oceanography during the survey is available at PANGAEA (Waniek et al., 2021).

Brief description of the methodology used: - Nitrate, nitrite, phosphate and silicate were measured by continuous flow analysis. - Oxygen was measured on one sample at each station by potentiometric Winkler titration. - DOC and DN were measured by catalytic oxidation after filtered with GF/F-filters. - POC and PON were measured by means of an elemental analyser after filtered with pre-combusted GF/F-filters. - Suspended particulate material (SPM) was determined gravimetrically after pre-combusted and weighted GF/F-filters filtration. - Chlorophyll a and phaeopigments were measured using a fluorometer after ethanol extraction of the GF/F-filters.

More information regarding the methodology used can be seen in Kuss et al. (in review).