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Passive tracer initialization

MSdueon12

Member
Hi, there

I am working on using the passive tracer in a convective event. I saw a tread give a direction to add a tracer_opt = 2 in each domain, and also dan_em/module_initial_real.F has presented the a small example on the centre of the domain, is that all? I used three domain, how can I set them? I only want to use one tracer, is that correct I only use tr17_1? Meanwhile, I want to see where the tracer is going in the simulation, do I need any change in dyn_em/solve_EM.F? I found some idea from internet that add some sentence in solve_EM.F

also, please see the attached files I have changed.
In this setting, the tracer disappears at the lower level it is strange.
I changed module_initialize_real.F at the lines of 4236 and the solve_EM.F at the lines of 267

Thanks so much.
 

Attachments

  • solve_em.F
    253.4 KB · Views: 13
  • module_initialize_real.F
    384 KB · Views: 14
Hi,
The tracer option can be activated in all the domains, e.g., D01, D02, D03, by setting
tracer_opt= 2, 2, 2
However, when you initialize tracer, the tracers are initialized by:
IF (config_flags%tracer_opt .eq. 2) THEN
DO j = (jde + jds)/2 - 4, (jde + jds)/2 + 4, 1
DO i = (ide + ids)/2 - 4, (ide + ids)/2 + 4, 1
IF ( its .LE. i .and. ite .GE. i .and. jts .LE. j .and. jte .GE. j ) THEN
tracer(i, 1, j, P_tr17_1) = 1.
tracer(i, 1, j, P_tr17_2) = 1.
tracer(i, 1, j, P_tr17_3) = 1.
.......
END IF
END DO
END DO
END IF
This indicates that depending on the location of child domain, the tracer can be released at different areas of the outermost domain (D01).

if you don't want tracers to be released every time step, then you don't need to change solve_em.F. You only need to modify dyn_em/module_initialize_real.F to put initial tracers to your area of interests. It is correct that you can use tracer(i, 1, j, P_tr17_1) in your case.
Please see more details in this document: https://www2.mmm.ucar.edu/wrf/users/tutorial/presentation_pdfs/201707/registry.pdf
 
Last edited:
Hi,
The tracer option can be activated in all the domains, e.g., D01, D02, D03, by setting
traj_opt = 2, 2, 2
However, when you initialize tracer, the tracers are initialized by:
IF (config_flags%tracer_opt .eq. 2) THEN
DO j = (jde + jds)/2 - 4, (jde + jds)/2 + 4, 1
DO i = (ide + ids)/2 - 4, (ide + ids)/2 + 4, 1
IF ( its .LE. i .and. ite .GE. i .and. jts .LE. j .and. jte .GE. j ) THEN
tracer(i, 1, j, P_tr17_1) = 1.
tracer(i, 1, j, P_tr17_2) = 1.
tracer(i, 1, j, P_tr17_3) = 1.
.......
END IF
END DO
END DO
END IF
This indicates that depending on the location of child domain, the tracer can be released at different areas of the outermost domain (D01).

if you don't want tracers to be released every time step, then you don't need to change solve_em.F. You only need to modify dyn_em/module_initialize_real.F to put initial tracers to your area of interests. It is correct that you can use tracer(i, 1, j, P_tr17_1) in your case.
Please see more details in this document: https://www2.mmm.ucar.edu/wrf/users/tutorial/presentation_pdfs/201707/registry.pdf
Thanks so much for your help, I just look up WRF User Guide, and realise that tracer_opt is not described in this handbook, it looks that tracer_opt is a parameter in WRF-chem? Another question is from the https://www2.mmm.ucar.edu/wrf/users/tutorial/presentation_pdfs/201707/registry.pdf , in Registry_EM.F ,
package tracer_test3 tracer_opt==3 - Does it influence the result?

Thanks so much

 
Hello,
I have a question about tracer_opt.
I have six domains, at the moment I turn on the tracer using tracer_opt=2, for domain 01-06. I would like to turn off the tracer for domain 01-05, just turn on for domain 6.
Is it corrected like this tracer_opt=1,1,1,1,1,2? Or using 0 to turn it off?

Thanks!
Hi,
tracer_opt does work for RWWF-ARW.
In the document https://www2.mmm.ucar.edu/wrf/users/tutorial/presentation_pdfs/201707/registry.pdf, tracer_opt =3 is used to demonstrate how to add specific tracers. For your case, the available option tracer_opt==2 is sufficient.
 
Hello Dr. Chen,

I would like to consult a question about running WRF-LES, the tracer was set like below in the module_initialize_real.F file
IF (config_flags%tracer_opt .eq. 2) THEN
DO j = (jde + jds)/2 - 4, (jde + jds)/2 + 4, 1
DO i = (ide + ids)/2 - 4, (ide + ids)/2 + 4, 1
IF ( its .LE. i .and. ite .GE. i .and. jts .LE. j .and. jte .GE. j ) THEN
tracer(i, 1, j, P_tr17_1) = 1.
I am wondering what the unit of the tracer emission value 1 above is. Could you please kindly guide me a bit on the unit?

Thanks a lot,
Yunsong
 
Thank you Dr. Chen, not tracer_opt=0,0,0,0,0,2?
I am sorry for the typo, --- you are right that it should be
tracer_opt=0,0,0,0,0,2
Hello Dr. Chen,

I would like to consult a question about running WRF-LES, the tracer was set like below in the module_initialize_real.F file
IF (config_flags%tracer_opt .eq. 2) THEN
DO j = (jde + jds)/2 - 4, (jde + jds)/2 + 4, 1
DO i = (ide + ids)/2 - 4, (ide + ids)/2 + 4, 1
IF ( its .LE. i .and. ite .GE. i .and. jts .LE. j .and. jte .GE. j ) THEN
tracer(i, 1, j, P_tr17_1) = 1.
I am wondering what the unit of the tracer emission value 1 above is. Could you please kindly guide me a bit on the unit?

Thanks a lot,
Yunsong
Yunsong,
There is no unit attached to the tracer. But you can assume its unit is kg/kg (just like the water vapor mixing ratio).
 
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