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User's Guide to NCAR CCM3.6 Search Page


2. Using CCM3.6
    2.4 Example Namelists


2.4.5 Example 5 -- Branch Run

In the following example, a new case is begun by "branching" from a CCM3 control run. The branch run allows the user to change any namelist variables associated with the history files, while continuing from a chosen point in a previous run.  Other namelist variables should not be modified. A branch run must always start a new case, so the namelist variable CASEID must be changed.  In this example, some fields are excluded from the primary history file, and placed on two auxiliary history files, to be written every 18 timesteps. Note the use of NSREST=3 for a branch run, and the additional values assigned to NDENS, MFILT, and NHTFRQ for the auxiliary file. 


 &CCMEXP
 CASEID = 'run05'
 CTITLE = 'CCM3 branch run'
 NCDATA = 'SEP1.T42.0198.nc'
 BNDTVS = 'T42M5079.nc'
 BNDTVO = 'ozn.0596.r8.nc'
 NSREST = 3
 NSWRPS = 'mypass'
 IRT    = 365
 RIRT   = 365
 NREVSN = '/USERNAME/run01/ccm3/rest/ccmr_00000902_00000' 
 NHTFRQ = 72,18,18
 NDENS  = 2,2,2
 MFILT  = 10,30,30
 NNBDAT = 000901
 NNBSEC = 0
 NNDBAS = 0
 NNSBAS = 0
 NELAPSE = -30
 NINAVG = 'A','X','M'
 AUXF   = '1','PRECL','PRECC','CLOUD',
          '2','PRECL','PRECC','CLOUD'
 EXCLUDE = 'PRECL','PRECC','CLOUD'
 IYEAR_AD = 1950
 /

 &LSMEXP
 nrevsn = 'lsmr_00000902_00000' 
 /


CASEID
A branch run must always start a new case.
NSREST
NSREST=3 indicates a "branch" run, which starts from a specific set of restart datasets and creates a new case.
NREVSN
This run uses master restart file ccmr_00000902_00000 from example 1 to provide the initial dataset for starting this case.  USERNAME in this example refers to the users logid.  A branch run also requires
that NREVSN be set for the lsm, again we use the lsm restart file written by example 1.
NHTFRQ
History file write frequency will be every 72 timesteps (1 day) for the primary file, and every 18 timesteps (6 hours) for the two auxiliary files.
NDENS
 All primary and auxiliary history files will be packed 2 to 1.
MFILT
10 time samples will be written to each primary history file. 30 time samples will be written to each auxiliary history file.
NINAVG
NINAVG = 'A','X','M' specifies the field type in each history file. The primary history file will be averaged (daily averaged since NHTFRQ(1)=72). Fields on the first auxiliary history file will contain the maximum values of the PRECL, PRECC and CLOUD fields for the past 6 hours (18 timesteps), and fields on the second auxiliary history file will contain the minimum values of the same fields for the past 6 hours.
AUXF
This list specifies that two auxiliary history files will be written containing the fields shown. Up to five such files may be declared.
EXCLUDE
To save file storage space, the fields that will be written to the auxiliary history files above are excluded from the primary history file.


 
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$Name: ccm3_6_6_latest3 $ $Revision: 1.38.2.1 $ $Date: 1999/03/25 21:37:59 $ $Author: erik $