Can artificial upwelling of nutrient-rich deep water help store more carbon dioxide in the ocean? This is the question addressed by the research project Test-artUp. As part of this project, mesocosm experiments were carried out to clarify

(1) whether repeated upwelling or the same amount of nutrients in one single pulse

(2) what ratio of surface to deep water (mixing ratio)

(3) what ratio of nitrate to silicate

is optimal for carbon export.

In addition, a wave-driven pump was deployed in the Atlantic Ocean south of the Canary Islands. Using only wave energy, the pump brought nutrient-rich water from 200 meters depth up to the sunlit surface layer, where they can be utilized by phytoplankton, microalgae that build the base of the oceanic food web. The test provides insights into the feasibility of using wave energy to bring deep water to the surface for the purpose of enhancing oceanic carbon dioxide uptake. In addition, an extensive measurement program accompanying the deployment is intended to provide information on the effects of artificial upwelling on marine life.

Unfortunately, the wave pump only functioned approximately 10 hours, too short to carry out the ambitious monitoring program.