How to model pollutant diffusion in a bay?

Discussion of how to use ROMS on different regional and basin scale applications.

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zhaoqian
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Joined: Tue Nov 11, 2008 5:45 pm
Location: National Marine Environmental Mornitoring Center

How to model pollutant diffusion in a bay?

#1 Post by zhaoqian » Mon Jan 11, 2010 4:15 pm

Hi all:
I want to model pollutants diffusion in a bay with one point source discharging about 1000 tons pollutants in one year into the sea. The initial concentration of the tracer is 1mg/L and the boundary concentration is set to be a constant(for example 1mg/L). How should I set the model? The following is my choice.
1) define T_PASSIVE in the cpp file
2) define ANA_PASSIVE, and modify the Functionals/ana_passive.h
3) define ANA_TOBC, modify the Functionals/ana_tobc.h
4) How to define the source?
Please give me some advices?Thank you!
Qian

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kate
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Re: How to model pollutant diffusion in a bay?

#2 Post by kate » Mon Jan 11, 2010 5:29 pm

ROMS has two kinds of sources and I've only ever used the one that happens along vertical walls (at u or v points) in the model. For that kind, set TS_PSOURCE and UV_PSOURCE. If the source is not at a vertical wall, try Q_PSOURCE. If your flux is fixed in time, the ANA_PSOURCE option should allow you to set its attributes.

zhaoqian
Posts: 45
Joined: Tue Nov 11, 2008 5:45 pm
Location: National Marine Environmental Mornitoring Center

Re: How to model pollutant diffusion in a bay?

#3 Post by zhaoqian » Tue Jan 12, 2010 1:42 am

Dear Kate and all:
I notice in your explaination and the cppdefs.h that there have three options (TS_PSOURCE, UV_PSOURCE, Q_PSOURCE) about sources.
I know that TS_PSOURCE is giving the value of T/S or the concentration of tracers, and notice that TS_PSOURCE and Q_PSOURCE are used in step3d_t.F while UV_PSOURCE are used in step3d_uv.F, but I don't know the difference between Q_PSOURCE and UV_PSOURCE. Furthermore, I found no obvious differences when activating Q_PSOURCE or UV_PSOURCE in ana_psource.h. I am so confused about these cpps!
Would you please explain the exact physical meaning to me. Thanks a lot for your help!
Qian

zhaoqian
Posts: 45
Joined: Tue Nov 11, 2008 5:45 pm
Location: National Marine Environmental Mornitoring Center

Re: How to model pollutant diffusion in a bay?

#4 Post by zhaoqian » Mon Jan 18, 2010 9:24 am

Hi all:
When I use Q_PSOURCE modeling transport and diffusion of pollutant discharging into the sea, and set Qbar and Qsrc positive, the concentration of the pollutant is negative, and when I set Qbar and Qsrc negative, the concentration becomes posivie. Why? Can anybody explain this for me?
Thanks for replying!
Qian

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