3D FlexSem model for Young Sound, NE Greenland [Software]

The FlexSem hydrostatic hydrodynamic model was configured for the Tyroler Fjord - Young Sound system and two-way coupled to a biogeochemical model. The unstructured computational mesh of orthogonal polygons was constructed using JigSaw. The horizontal resolution ranges from 230 m at the sill into the fjord to 450 m at the open boundary. In the vertical, the model has 54 layers: one 1.5 m surface layer which varies in thickness to accommodate the free surface, 5 layers of 0.5 m, 6 layers of 1.0 m, 10 layers of 2.0 m, 5 layers of 5.0 m, and the remaining 21 layers are 10 m thick. The model has a total of 181,324 computational cells. The applied biogeochemical model in the FlexSem framework is based on the ERGOM model modified to Greenland coastal waters. In the current version, 11 state variables describe concentrations of four dissolved nutrients (NO₃, NH₄, PO₄, SiO₂), two functional groups of phytoplankton (diatoms, flagellates), micro- and mesozooplankton, detritus (NP), detritus-silicon, and oxygen. The model currency is N using Redfield ratios to convert to P and Si. Chlorophyll a (Chl a) was estimated as the sum of the two phytoplankton groups. The model considers the processes of nutrient uptake, growth, grazing, egestion, respiration, recycling, mortality, and detritus sinking.