Articles | Volume 8, issue 10
Development and technical paper
08 Oct 2015
Development and technical paper |  | 08 Oct 2015

S2P3-R (v1.0): a framework for efficient regional modelling of physical and biological structures and processes in shelf seas

R. Marsh, A. E. Hickman, and J. Sharples

Abstract. An established one-dimensional (1-D) model of Shelf Sea Physics and Primary Production (S2P3) is adapted for flexible use in selected regional settings over selected periods of time. This Regional adaptation of S2P3, the S2P3-R framework (v1.0), can be efficiently used to investigate physical and biological phenomena in shelf seas that are strongly controlled by vertical processes. These include spring blooms that follow the onset of stratification, tidal mixing fronts that seasonally develop at boundaries between mixed and stratified water, and sub-surface chlorophyll maxima that persist throughout summer. While not representing 3-D processes, S2P3-R reveals the horizontal variation of the key 1-D (vertical) processes. S2P3-R should therefore only be used in regions where horizontal processes – including mean flows, eddy fluxes and internal tides – are known to exert a weak influence in comparison with vertical processes. In such cases, S2P3-R may be used as a highly versatile research tool, alongside more complex and computationally expensive models. In undergraduate oceanography modules and research projects, the model serves as an effective practical tool for linking theory and field observations. Three different regional configurations of S2P3-R are described, illustrating a range of diagnostics, evaluated where practical with observations. The model can be forced with daily meteorological variables for any selected year in the reanalysis era (1948 onwards). Example simulations illustrate the considerable extent of synoptic-to-interannual variability in the physics and biology of shelf seas. In discussion, the present limitations of S2P3-R are emphasised, and future developments are outlined.

Short summary
Our relatively shallow shelf seas are warmed at the surface in spring and summer, while strong tidal currents act to mix away the surface warmth. These competing effects strongly influence the conditions for seasonal growth of the phytoplankton that support marine food webs. We have developed a versatile framework for fast computer modelling of shelf seas, to explore seasonal and year-to-year variations of warming and plankton productivity, tested against observations in different regions.