FAQ
This FAQ aims to provide basic explanations about the meaning of some model entries and to clarify scientific jargon. Please also take a look at the already uploaded model entry forms.
| Explanations and comments to the model entries | |
|---|---|
| What if I don’t know the answer to a question? | You can leave a question open if you don’t know the answer and we will help you; or you can contact us via aemonj.models@gmail.com |
| My answer is not among the options, or there is important information that is not in the questions. | We welcome you to put additional information in the comment section at the end of the entry form |
| What components does my model have? |
Hydrodynamics: Simulation of water motions, heat transfer and temperature Chemistry: Simulation of water quality – including oxygen and nutrients – or more specific chemical processes (e.g. methane ebullition) Biology: Simulation of at least one biological component, e.g. phytoplankton, zooplankton, or fish |
| How can I imagine the model structure? | |
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| How are the widths of each layer formulated? | Flexible grid: Model layers act as ‘control volumes’ and can modify their thickness (a.k.a. Lagrangian structure) Fixed grid: Thickness of each model layer is fixed (a.k.a. Eulerian structure) |
| What is a catchment model? | With catchment model is meant that the model exists of multiple cells that model the catchment, and therefore extend outside of a lake, reservoir or sea |
| What are the types of input variables? |
Obligatory: State variables that are crucial to run the model Optional: State variables that can be added to reduce model assumptions |
| What are these different file formats? |
ASCII: Standard code for electronic communcation, easily readable with a text editor .netcdf: Network common data format, written in binary and mostly used in scientific applications .csv: Comma-separated values, plain text, used to easily store tabular data .xls: Spreadsheet data from Microsoft Excel |
| What are these mathematical frameworks? |
ODE: Ordinary differential equations like dx/dt=x PDE: Partial differential equations like the heat equation du/dt – a ( d²u/dx² + d²u/dy² ) = 0 |
| What is the calibration step? | Fitting simulated data to observed data, mostly followed by a validation step in which the model fit is checked for a different simulated time period |
| What do you mean by shallow and deep? | Not clearly defined; for most applications a lake/reservoir with a mean depth below 10 m could be declared as shallow; whereas often shallow also means that the photic zone reaches to the bottom of the lake |
| What are the meanings of the trophic criteria? |
Oligotrophic: Low concentrations of nutrients and low primary production Mesotrophic Intermediate concentrations of nutrients and moderate primary productivity: Eutrophic: High concentrations of nutrients and high primary productivity causing oxygen depletion |
| What are the differences regarding accessibility? |
Open-source: Freely available access to source code Open-to-use: No access to source code |
| What are examples for the processing tools? |
Pre-processing: Aggregates automatically input and boundary conditions, e.g. Janet for grid and mesh generation Post-processing: Visualizes model results and computes additional parameters from model results, e.g. glmtools for GLM or LakeAnalyzer |
| What are internal waves? | Oscillating gravity waves that occur in stratified surface water bodies (see also seiches) |