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courant limit in aqua-planet

Hi Neale,
With actual planet I was finding the courant limit message and after listening from your end (above quoted) I did not worry for the same. But in the mean time I have to repeat the same experiment with the aqua-planet option and the model is blowing up after a few time steps.
I am trying to run CAM3.0 with Eulerian dynamical core in the T85 resolution, the default timestep for which is 600 seconds. While I run the model with 600 sec timestep size, I get the following error(in the out file) :


NSTEP = 28 9.365288304488823E-05 3.460147472381840E-05 253.956 9.84623E+04 2.450116512584044E+01 2.09 2.78
nstep, te 29 3335056539.95965433 5.32393053372700997 -0.531410799993233289E-03 98462.2625909176131
COURLIM: *** Courant limit exceeded at k,lat= 1100 (estimate = 1.338), solution has been truncated to wavenumber 63 ***
COURLIM: *** Courant limit exceeded at k,lat= 2100 (estimate = 1.328), solution has been truncated to wavenumber 63 ***


significant conservations error energy after vdiff count 2 nstep 30 chunk 1730 col 13
3402751082.34408236 3411794488.29973936 -9044887.03703641891 -122535.076653514130 -1481.08137938881737 0.265062918088194771E-02
significant conservations error water after vdiff count 3 nstep 30 chunk 1730 col 13
27.5074768764597799 30.6974479291840296 -3.19018436136459727 -0.213308641130876766E-03 -0.213308640348517834E-03 0.103915768305948356
CUBYDR: Departure point out of bounds: jcen,icount,nlon*plev= 102 6655 6656
ENDRUN: called without a message string



Then I reduced the time step size gradually up to 3 minutes at which the model ran successfully.

As many times it is seen that, the upper tropospheric jets limits the time step (courrant limit), but in my above experiment the underlying SST was the default condition "sst option one". I think with this SST the upper tropospheric jet should not be so strong to cause the above problem.

But, please note that SLD with T85,128X256 is runnig successfuly with 30 minutes (default) time step.

For my experiment I would like to run the model with T85 on 128x256 with 10 minutes time step size with Eulerian dynamical core. Any suggestions on this will be highly helpful.


Thanking you in Advance,
Saroj​
 
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