{"last_commit_sha":"bcf99f4064006dd29d9f5e537c3c65c4d96b18ab","persisted":true,"title":"Tracer model","content":"[Home](Home) [[_TOC_]] A simple tracer model has been developed to run tracer models with inert or reactive tracers. This model has only one state variable (Tracer). The units are dimensionless (-), but can also be interpreted as concentrations (e.g. g m^-3). The tracer is only influenced by transport and a decay. The model can be run for one tracer at the time. [top](Tracer model) # Transport The tracer (Tracer) is transported by tidal currents. This transport is modeled as exchange rates between the neighboring compartments with the same formulation as in the NPZ model. It is assumed that the exchange rates are bi-directional, i.e. the exchange rate [m³ d^-1] from compartment $`i`$ to compartment $`j`$ is the same as the exchange rate from compartment $`j`$ to $`i`$. ```math Flux_{i,j} = \frac{Ex_{i,j}\cdot(Tracer_{j}-Tracer_{i})}{Vol_{i}} ``` Where $`Flux_{i,j}`$ is the increase in Tracer in compartment $`i`$ [d^-1] due to the water exchange between compartment $`i`$ and $`j`$. $`Ex_{i,j}`$ is the exchange rate between compartment $`i`$ and $`j`$ [m³ d^-1]. $`Tracer_{i}`$ and $`Tracer_{j}`$ are the Tracer fractions [-] in compartment $`i`$ and $`j`$, respectively. $`Vol_{i}`$ is the volume of compartment $`i`$ [m³]. [top](Tracer model) # Decay The decay of the tracer is described by an exponential function: ```math \frac{dTracer}{dt} = -r \cdot Tracer ``` where $`r`$ is the first-order decay rate of the tracer [d^-1]. In case the decay rate is 0, the tracer is inert. The tracer model with an inert tracer is used to calibrate the exchange rates between the model compartments. [top](Tracer model)","front_matter":{},"format":"markdown","uploads_path":"https://git.wur.nl/api/v4/projects/6346/wikis/attachments","slug":"Tracer-model","path":"/wijsm006/demo/-/wikis/Tracer-model","wiki_path":"/wijsm006/demo/-/wikis/home","help_path":"/help/user/project/wiki/index.md","markdown_help_path":"/help/user/markdown.md","markdown_preview_path":"/wijsm006/demo/-/wikis/Tracer-model/preview_markdown","create_path":"/wijsm006/demo/-/wikis"}