Passive tracer tracking

Author

Fulton, Beth (Environment, Hobart)

Published

May 22, 2018

We have added a flag into the trunk code so that the SED tracer will be read into the model even if the model is not estuarine. This should allow for a passive tracer to be tracked. You might want to do this when checking to see if the model transports correctly capture hydrodynamic exchanges and currents.

To use this option

  1. In run.prm add

flagpassivetracer     1    # Flag indicating whether a passive tracer is needed for tracking tranpsorts or not (1 = yes, 0 = no)

  1. In the in.nc file you need to add the tracer. In the header (text section at the start of the file) add the following

double SED(t, b, z) ;

SED:bmtype = “tracer” ;

SED:units = “mg N m-3” ;

SED:long_name = “Passive tracer” ;

SED:sumtype = 1 ;

SED:dtype = 0 ;

SED:inwc = 1 ;

SED:insed = 1 ;

SED:dissol = 0 ;

SED:decay = 0. ;

SED:partic = 1 ;

SED:passive = 1 ;

SED:svel = 0. ;

SED:xvel = 0. ;

SED:psize = 1.e-06 ;

SED:b_dens = 1000000000. ;

SED:i_conc = 200000000. ;

SED:f_conc = 200000000. ;

SED:isabs = 0 ;

SED:iscontam = 0 ;

SED:_FillValue = 0. ;

Then in the data section of the file you need to add

SED =

N, , ;

Where N is the tracer doping you want to use if you want it to be there at the start of the model. You could also introduce it later on as a point source. Let me know if you want to do that (its like adding a river inputs so really straight forward).

As to the _ you need as many data entries in total as there are layers (water column + sediment layers) * number of boxes in the model (lets call that value “LxB”. Now the N needs one entry so the total number of _ you need is (LxB -1)

So for a model with 3 layers in 4 boxes where N is entering in box 1 you would have

SED =

, , _,

N, , ,

, , _,

, , _ ;

At present it really only makes sense to dope one location at a time with the N otherwise you won’t know where things have come from as you can’t have more than one SED variable at a time. If you need multiple tracers for some reason please contact us for an alternative solution.


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