Coupled 3D physical and biological modelling of the mesoscale variability observed in North-East Atlantic in spring 1997: biological processes

• Published in: Deep-sea research. Part I, Oceanographic research papers Vol. 49; no. 10; pp. 1741 - 1768
• Main Authors: Popova, E.E, Lozano, C.J, Srokosz, M.A, Fasham, M.J.R, Haley, P.J, Robinson, A.R
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-10-2002; Elsevier; Pergamon Press Inc
• Subjects: Computer based modeling; Data assimilation; Earth, ocean, space; Ecosystems; Exact sciences and technology; External geophysics; Mesoscale processes; Modelling; Oceanography; Physical and chemical properties of sea water; Physics of the oceans; East Atlantic; Atlantic Ocean; North Atlantic; Modelling; Mesoscale processes; Ecosystems; Data assimilation; Ship observation; Three dimensional model; Mesoscale; Plankton; Spring(season); Coupling; Biological activity
• ISSN: 0967-0637; 1879-0119
• DOI: 10.1016/S0967-0637(02)00091-2

A limited area, eddy resolving coupled physical and biological model and data assimilation are used to reproduce and analyse the ecosystem variability observed in the North-East Atlantic in April–May 1997 on
Discovery cruise 227. The ecosystem was in a post-bloom grazing controlled regime. The combination of the deep mixing in the upper layer during the cruise and a deeper than average winter convection led to high-nutrient–low-chlorophyll type conditions, which are unusual for this location. These conditions and lack of strong mesoscale physical features led to low spatial variability of phyto- and zooplankton yet strong sensitivity to the variations in the vertical mixing (storm event). Modelling results show that plankton patchiness formation under these conditions was dominated by biological mechanisms (mainly predator–prey oscillations). Furthermore, this mechanism, together with mixing and stirring, are responsible in this order for the observed scales and variability of patchiness from homogeneous low winter concentrations of phyto- and zooplankton.