Inert Passive Tracer

[susonic]

Hi all
I'm trying to use inert passive tracer by ANA_PASSIVE.
But I don't know for sure how to use it. Is there anyone who can give me an
example file of ANA_PASSIVE so that I can reference it in my case.
Right now I'm going to use those tracers as a diffusion of oil spill.

! Logical switches (TRUE/FALSE) to activate writing of extra inert passive
! tracers other than biological and sediment tracers. An inert passive tracer
! is one that it is only advected and diffused. Other processes are ignored.
! These tracers include, for example, dyes, pollutants, oil spills, etc.
! NPT values are expected. However, these switches can be activated using
! compact parameter specification.

I read this in ocean.in file that we can apply these passive tracers above situation.
Any example would be great for me.
Thank you.

[kate]

You need to #define T_PASSIVE to get passive tracers. The flag ANA_PASSIVE determines whether or not the initial conditions are analytic (from ana_passive.h) or from the initial condition file. As for boundary conditions, all tracers have either analytic boundary conditions or they all come from the same boundary condition file. If you need to read values from a file, the field names are dye_01, dye_02, etc. I successfully set up a uniform dye_01 using ANA_PASSIVE with boundary conditions from a file. The boundary file has u,v,T,S for many times and (analytic) biological values for the beginning and end times. I have a script to read one biology value, change the attributes and the value to my uniform value, then write it into the boundary file with the name dye_01_west, etc. I then had to edit varinfo.dat to reflect that it's using bio_time rather than ocean_time. Let us know if you have more specific questions.

[susonic]

Hi Kate. Thank you so much for your information. It really helps me to understand more about passive tracer.
Would you mind if I request your file which has passive_tracer or matlab xxx.m file which is used
for making passive boundary or initial file?
Or your ana_passive.h file would be also great to me for understanding more about how to handle the passive tracer.
You can send me an email to ocean0510@gmail.com or if it's available you can upload the files
to here.
Thank you.
Regards,
-Peter

[kate]

I can do here. Note that set_inert_bc is actually an NCL script. Use:

Code: Select all

ncl set_inert_bc.ncl

after setting the filename, etc. inside. This sets a uniform value at two times, before and after the beginning and ending times of your run.

[susonic]

Thank you Kate. That's very nice of you to upload here so that anyone who
is wondering about the function can downdload and use it.
Well I need to analyze the script which you uploaded and I will apply in my case.
Thanks again. Have a great day!

Regards,
-Peter