Size fractionated primary productivity rate measurements through 14C radioisotope incorporation rates from a KOSMOS mesocosm experiment carried out in the frame work of the Ocean Artificial Upwelling project. The experiment was performed in the North-East Atlantic Ocean off the coast of Gran Canaria in autumn 2018 and lasted for 39 days. In this study we investigated the effect of different intensities of artificial upwelling combined with two upwelling modes (recurring additions versus one singular addition) on the phytoplankton community. Data shown includes production rates of dissolved organic carbon, particulate organic carbon in 3 size fractions (0.2-2 µm, 2-20 µm, >20 µm) and total organic carbon.