ERSEM 15.06: a generic model for marine biogeochemistry and the ecosystem dynamics of the lower trophic levels

Abstract

Abstract. The European Regional Seas Ecosystem Model (ERSEM) is one of the most established ecosystem models for the lower trophic levels of the marine food web in the scientific literature. Since its original development in the early nineties it has evolved significantly from a coastal ecosystem model for the North Sea to a generic tool for ecosystem simulations from shelf seas to the global ocean. The current model release contains all essential elements for the pelagic and benthic parts of the marine ecosystem, including the microbial food web, the carbonate system, and calcification. Its distribution is accompanied by a testing framework enabling the analysis of individual parts of the model. Here we provide a detailed mathematical description of all ERSEM components along with case studies of mesocosm-type simulations, water column implementations, and a brief example of a full-scale application for the north-western European shelf. Validation against in situ data demonstrates the capability of the model to represent the marine ecosystem in contrasting environments.

Bridging the Gap between Knowing and Modeling Viruses in Marine Systems—An Upcoming Frontier

“…Some models have a loss term loss of phytoplankton carbon due to nutrient stressed lysis caused by mechanical failure and viruses (Vichi et al, 2007;Mateus, 2012b;Petihakis et al, 2012;Hasumi and Nagata, 2014), frequently staying close to the approach proposed in early models such as the ERSEM model (BarettaBekker et al, 1997;Butenschön et al, 2016). In other cases viruses are assumed to be a minor phytoplankton loss mechanism (Stock et al, 2014), parameterized as weak density-dependent loss term on small phytoplankton, following early and simpler modeling approaches (Suttle, 1994).…”

An Exact Solution For Modeling Photoacclimation of the Carbon-to-Chlorophyll Ratio in Phytoplankton

“…But to estimate the impact that the exact solution might have on the calculated fields of carbon-to-chlorophyll ratio, we have to consider the time scales over which light is averaged, before carbon-to-chlorophyll ratio is computed in the models. For example, in the European Regional Seas Ecosystem Model (ERSEM), the instantaneous light field is used to compute θ at each time step of the model (Butenschön et al, 2016). The common time step for ERSEM is 15 min.…”

“…But the approximation used to derive the solution to the photoacclimation model (Geider et al, 1997) still limits the range of irradiance levels for which the solution holds. Some authors have addressed this problem by a numerical solution to the Geider et al (1997) model rather than the approximation (e.g., Li et al, 2010), while others have imposed a numerical upper limit on the C:Chl ratio (Butenschön et al, 2016) to constrain model output.…”

Net primary productivity estimates and environmental variables in the Arctic Ocean: An assessment of coupled physical-biogeochemical models

“…The CICE model [Hunke et al, 2013] has several interacting components: a thermodynamic submodel, an ice dynamics submodel, a vertical and a horizontal transport submodel. ERSEM is a lower trophic level biogeochemical cycling, carbon-based process model that uses the functional-group approach [Blackford et al, 2004;Butensch€ on et al, 2016]. The C, N, P, Si, and Fe cycles are explicitly resolved with variable stoichiometry.…”