Vertical profiles of photochemically induced percent changes in dissolved organic matter in samples from SEATS and F2@en

Two stations were visited in the western tropical Pacific Ocean: The South-East Asia Time-series Station (SEATS) in the northern South China Sea (SCS) and station F2 in the Philippine Sea, ~230 km to the northeast of the Luzon Strait. Water samples were taken aboard the R/V Dong-Fang-Hong 2 in July and August 2017 from 13 depths between 5 m and 3800 m at SEATS and 11 depths between 5 m and 3200 m at F2 using Niskin bottles mounted on a SeaBird 911 conductivity-temperature-depth (CTD) rosette sampler. The percentage change of different parameters was calculated as the ratio of the signal difference of property X before and after irradiation to that before irradiation.