Difference between revisions of "Tips and Tricks"

(Unstable WRF simulation)
 
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If you notice that the WRF model has become unstable, you should consider making the following changes in the namelist.input file:
 
If you notice that the WRF model has become unstable, you should consider making the following changes in the namelist.input file:
  
(a) reduce the time-step; and/or
+
# reduce the time-step; and/or
 +
# set w_damping to 1; and/or
 +
# set epssm (0.1 by default) to a higher value (e.g. 0.3)
  
(b) set w_damping to 1; and/or
+
The changes above indeed improved the stabilities in our case.
  
(c) set epssm (0.1 by default) to a higher value (e.g. 0.3)
+
You can also explore the following ideas:
 
+
# reduce the total number of processors
The changes above indeed improved the stabilities in our case.
+
# change the decomposition through nproc_x and nproc_y options
 +
# reduce the level of optimisation via re-compilation
  
 
== Runtime segmentation error ==
 
== Runtime segmentation error ==

Latest revision as of 22:41, 11 December 2019

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Unstable WRF simulation

If you notice that the WRF model has become unstable, you should consider making the following changes in the namelist.input file:

  1. reduce the time-step; and/or
  2. set w_damping to 1; and/or
  3. set epssm (0.1 by default) to a higher value (e.g. 0.3)

The changes above indeed improved the stabilities in our case.

You can also explore the following ideas:

  1. reduce the total number of processors
  2. change the decomposition through nproc_x and nproc_y options
  3. reduce the level of optimisation via re-compilation

Runtime segmentation error

WRF will always crash with a segmentation error when compiled without debugging information.

But you should make sure, you always run WRF with an unlimited stacksize. This should be set in your run script.

For TCSH

limit stacksize unlimited

For BASH

ulimit -s unlimited (for BASH)

If you have some tricks that can help WRF users in our community and hope that they could be included on this page, please email cws_help@nci.org.au.