Modeling the inter-annual variability of ocean circulation and marine ecosystem in the Canary upwelling system

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A three‐dimensional eco‐hydrodynamical model of high resolution is applied to simulate the seasonal and interannual variability of ocean circulation and marine ecosystems in the CentralEastern basin of the North Atlantic (CENA) including the Canarian upwelling system. Simulated temperature and salinity fields agree well with satellite and expeditionary observations in the period 1998–2006. According to model results and observations, in winter, “spots” of maximal phytoplankton biomass are often located in upwelling zones in the open ocean on the periphery of cyclonic eddies rather than in the coastal upwelling zones. In summer, when phytoplankton biomass reaches maximal values, maxima of phytoplankton are located in the coastal upwelling zones. Simulated surface phytoplankton distributions are in qualitative agreement with surface distributions of chlorophyll a derived from satellite data. Interannual changes in mean annual temperatures averaged over CENA region for the period from 2000 to 2006 amounted to 0.9°C and 1.0°C for the model and satellite data, respectively. Similar changes in primary production for the period from 1998 to 2006 amounted to +60, –100, and 50 mg C m–2 d–1 (+6, –13, and +12% of its mean annual values), respectively, according to the model results, satellite‐derived estimate based on the Epply version of standard evaluation method, and satellite‐derived estimate based on carbon method. Despite the existing quantitative divergences between model results and satellite data, the spatial distributions during the various periods of an annual cycle were similar. Results of sensitivity studies are also presented