NSFC Major Program
Principal Investigator: Minhan Dai
Duration: 2019-2023
Budget (10K）: 1984.9
Project Number：41890800
The oligotrophic ocean occupies about 30% of the ocean surface and has been conventionally regarded as ocean deserts. It is characterized by nutrient depletion in the surface waters and extremely low net biological production and hence, per unit area, contributes little to carbon export from surface to deep waters. Emerging evidence, most notably based on ocean time-series studies such as those at the Hawaiian Ocean Time-series station, has shown a wider than previously assumed dynamic range of nutrient inputs and biological responses in this oceanic system. This project selects the North Pacific Subtropical Gyre (NPSG), one of the world’s largest oligotrophic regimes, as the study site to examine carbon fixation and export, or the biological pump in general, regulated by differently sourced nutrients including macronutrients (i.e., N, P, Si) and micronutrients (e.g., Fe).
The major objectives of this project are (1) to determine the distribution of macro- and micro-nutrients, fingerprint their sources and estimate their fluxes into the NPSG, (2) to constrain the spatial-temporal variability of biological N2 fixation and its limiting factors in the NDL, (3) to quantify the carbon fixation and associated planktonic community structure, (4) to constrain the export production from both the NDL and NRL, and (5) to simulate the biological pump and carbon sinks in the NPSG. This project can substantially improve our understandings to fundamental biogeochemistry in these climatically and ecologically important oligotrophic ocean systems.
Web: http://Carbon-Fe.xmu.edu.cn
