Moetasim <mashfaq@purdue.edu>

Hi Maryam,

Here are the steps for nesting :

1) rename original RegCM folder to some other name

2) extract regcm.tar.gz code! so now you have two RegCM: original & new 

3) follow the normal procedure for linking the files in
DATA folder (in new RegCM) with datalinker.x and 
link the output folder of your previos run in original RegCM to a link named RegCM from within the DATA folder. 
eg. ln -s ../../../RegCM_old/mysimulation/output RegCM

4) In domain.param ( of the new RegCM ofcourse) in addition to the routine steps
(ie selecting iy,jx ,ds, clat,clon etc.) choose DATTYP='FNEST'
then execute terrain.x 
Prompt will ask to input the original size of the ARAYS
JX_O, IY_O, KZ_O
Now say if iy=100 jx=90 kz =18 in your domain.param of
original Regcm then you should enter:
88,98,18 ! ie substracting 2 from iy and jx  
also note that the domain you have selected for the
new
 regcm should be completely inside the bigger
(original) domain and also for obvious reason time
span of simulation for further nested run should not
exceed that of original run.

Other step are same as for running normal simulation.
Make sure to select appropriate time step in regcm.in for high resolution run

Hope this help. Let me know if you find any difficultly

Jagaish