Eliminating fluxes by distance from the TC center

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A_Kowaleski

New member
Hello,

I am trying to modify module_sf_sfclayrev.F to eliminate surface fluxes based on distance from the tropical cyclone center. To find the TC center, I seek to use the minimum pressure in the domain (simple, but it should work for stronger storms, which I am simulating). I also want to find the location of maximum 10-meter wind speed, so that I can eliminate fluxes as a function of the radius of maximum winds.

How do I go about computing the min pressure/max wind over the entire domain? Although my modified module_sf_sfclayrev.F compiles correctly, I think that I am currently having difficulty because it computes min pressure/max wind over tiles, rather than the entire domain. For example, within SFCLAYREV:

PMIN_LOC)=MINLOC(PSFC)
WSPD_MAX=MAXVAL(WSPD10)

Is computing the min/max over the entire domain possible within module_sf_sfclayrev.F? If so, how? If not, what do you suggest?

Thank you

Hi,
Take a look at this section of our Users' Guide, which provides information on producing output diagnostics:
http://www2.mmm.ucar.edu/wrf/users/docs/user_guide_v4/v4.1/users_guide_chap5.html#output_diags
A couple of the options can calculate the maximum 10-m wind speed. You may be able to choose one and modify the code to do something similar for Pressure, as well. Doing it this way would require that you run the model to determine these values, and then if you were going to make modifications to the physics based on those calculations, I suppose you would have to run it again. This may not be ideal. However, perhaps you could follow the basic algorithms for the computations done in the diagnostics code to modify your code to do what you need, during run time?

Thank you for the assistance on this.

I know that module_sf_sfclayrev.F already uses 10-meter wind speed and surface pressure in its calculations, so getting those quantities shouldn't be an issue. However, I think the issue is that the domain is divided into tiles. Therefore, my modifications have succeeded (I think) in finding the location of minimum pressure and maximum wind in individual tiles, though not across the whole domain.

I may have found a workaround, though. Given that the TC center remains at/very near the nest center, I can compute distances based on (I,J) position relative to the center of the domain. This won't work for the outermost domain, but should work for the nested inner domains. I can then compute the radius of maximum winds from the unperturbed simulation and use that to estimate RMW-relative distances.