Location and size of perturbation bubble in WRF ideal

[Dr_MRW]

Hi,

I have been toying with the initial perturbation bubble in the module_initialize_ideal.F file for the size and location of the initial perturbation bubble, but I can't seem to understand how the radius and the location change as I vary the parameters. I have have changed each variable many times and I can't seem to find a pattern. It is also a bit troublesome to do it this way because it requires that I recompile WRF each time I tweak the parameters.

the code i am trying to modify starts at line 1095 for the quarter_ss case and looks similar for the LES case. I have bolded which variables I have tried changing.

DO J = jts, min(jde-1,jte)
yrad = config_flags%dy*float(j-nyc)/10000.
! yrad = 0.
DO I = its, min(ide-1,ite)
xrad = config_flags%dx*float(i-nxc)/10000.
! xrad = 0.
DO K = 1, kte-1

! put in preturbation theta (bubble) and recalc density. note,
! the mass in the column is not changing, so when theta changes,
! we recompute density and geopotential

zrad = 0.5*(grid%ph_1(i,k,j)+grid%ph_1(i,k+1,j) &
+grid%phb(i,k,j)+grid%phb(i,k+1,j))/g
zrad = (zrad-1500.)/1500.
RAD=SQRT(xrad*xrad+yrad*yrad+zrad*zrad)
IF(RAD <= 1.) THEN
grid%t_1(i,k,j)=grid%t_1(i,k,j)+delt*COS(.5*PI*RAD)**2
grid%t_2(i,k,j)=grid%t_1(i,k,j)
qvf = 1. + rvovrd*moist(i,k,j,P_QV)
grid%alt(i,k,j) = (r_d/p1000mb)*(grid%t_1(i,k,j)+t0)*qvf* &
(((grid%p(i,k,j)+grid%pb(i,k,j))/p1000mb)**cvpm)
grid%al(i,k,j) = grid%alt(i,k,j) - grid%alb(i,k,j)
ENDIF
ENDDO

Does anyone know which parameters do what and the right order to try changing them?

Many thanks