[MITgcm-support] tracers
Martin Losch
Martin.Losch at awi.de
Wed Sep 23 03:28:55 EDT 2009
Hi Alan,
I am not sure if I understand exactly, what you want to do exactly,
but (if you are using pkg/exf) there is a field called runoff (units
are m/s). All you need to do is add this to a ptracer-field, the best
place would be S/R PTRACERS_FORCING_SURF:
surfaceForcingPTr(i,j,bi,bj,iYourTracer) =
runoff(i,j,bi,bj)*_ra(i,j,bi,bj) * drF(ks)*_hFacC(i,j,ks,bi,bj)
(ks=1 in z-coordinates); because this is an absolute volume add it at
the end of the routine (to avoid the dilution of volume). Then you'd
have a volume of freshwater from runoff in m^3 in the ptracer
iYourTracer (the cell thickness is taken out again when
surfaceForcingPTr is applied in ptracers_forcing). The disadvantage is
that you can accumulate more fresh water from runoff in a grid cell
than the cell can hold which is kind of unsatifactory. Alternatively
you could add a tracer of some concentration (e.g. 1units/m^3) to the
run-off, but that appears to me more complicated: In this case I would
add the tracer at the beginning of the routine as
surfaceForcingPTr(i,j,bi,bj,iTrc) = runoff(i,j,bi,bj) * 1 (units/m^3)
Because this is a now a concentration, it should be diluted by
additional EmP (but not mR), so that you'd have to remove the runoff
from the EmPmR and PmEpR in the following lines of code.
Martin
On Sep 22, 2009, at 9:51 PM, Alan Condron wrote:
>
>
> Does anyone know if it possible to add a tracer directly to the
> model runoff
> field? For example, instead of adding a ptracer field in a grid cell
> that
> corresponds to a river mouth, I would like the freshwater that runs
> off into
> the model in this region to already have a tracer in it. In this
> way, I will
> know that I'm tagging only freshwater from this source. Is this
> possible to do?
>
> Many thanks,
> Alan
>
> ----------------------------------------------------------------
> This message was sent using IMP, the Internet Messaging Program.
>
> _______________________________________________
> MITgcm-support mailing list
> MITgcm-support at mitgcm.org
> http://mitgcm.org/mailman/listinfo/mitgcm-support
More information about the MITgcm-support
mailing list