Gotm Sopran Kickoff

8/12/2019 Gotm Sopran Kickoff

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Inga Hense & Hans Burchard

What is GOTM ?GOTM is a Public Domain water column model with alibrary of state-of-the-art turbulence closure models

GOTM has a module with biogeochemical models rangingfrom NPZ-type to complex ecosystem models such asERSEM and chemical models (IRON, ROLM)

GOTM turbulence and bio modules are integrated into 3Dcirculation models

GOTM has a large user community

GOTM has a website with source code, documentation andscenarios for download

GOTM has a graphical user interface (GOTM-GUI)


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Online since 1999, 50000 logins, mostly from Canada & US


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GOTM Physics

Prognostic equations for current velocity, salt,temperature, turbulent kinetic energy (TKE) and TKE

dissipation rate (or other length scale) Horizontal gradients neglected or parameterised

Surface forcing via standard bulk formulae

Simple bi-modal light absorption

Effects of surface wave breaking considered Good quantitative reproduction of field observations

of turbulence


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Surface dynamics in the Baltic Proper simulated with GOTM

Reissmann et al., 2007


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GOTM-turb module in 3D models

ROMS: generic model recoded from GOTM

MOM-4: turbulence module integrated

POLCOMS: turbulence module integrated FVCOM: turbulence module integrated

MOHID: turbulence module integrated

OPA: test implementations by different groups

BSH-model: implementation under work


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Biogeochemical models in GOTM

Implementation constraints: Large number of models possible

Easily extendable

Large choice for numerical solvers for r.h.s.

Integration into 3D models supported Implemented models

NPZD, Fasham, ERGOM, IRON, ROLM, ERSEM, Cyano LifeCycle, SPM, ...

New solvers for r.h.s. developed for GOTM-BIO Positive definite Modified Patankar solvers (Burchard et al.,

2003, 2005)

Positive definite Extended Modified Patankar solvers(Bruggeman et al., 2006)

See Burchard et al. (2006) for an overview


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Surface nutrient from NPZD model in Northern North Sea with different solvers

Explicit solver at long time steps (left) does not obey nutrient limitation. Stiff solver (right,Burchard et al. [2003, 2005]) is stable and accurate. Note the different scales.



GOTM-Bio in 3D models: GETM-BFM for the North Sea

GETM:3d-hydrodynamical model

BFM (


9/10Inga Hense & Hans BurchardSimulation and animation by Piet Ruardij (NIOZ)

Surface Chlorophyll in the North Sea from GETM-BFM



Bottom oxygen in late summer

Surface nitrate in summer

Surface nitrate before spring bloom

GETM-BFM for North Sea simulation

Results provided by Paul McCloghrie (CEFAS)

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Gotm Sopran Kickoff