Eulerian T85 of CAM3

[sandeep_sahany@indiatimes_com]

Dear CAM users,
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 :

COURLIM: *** Courant limit exceeded at k,lat= 1 20 (estimate = 1.196),
solution has been truncated to wavenumber 70 ***
COURLIM: *** Courant limit exceeded at k,lat= 2 18 (estimate = 1.007),
solution has been truncated to wavenumber 84 ***
*** Original Courant limit exceeded at k,lat= 1 20 (estimate = 1.196) ***
*** Original Courant limit exceeded at k,lat= 2 18 (estimate = 1.007) ***

The model doesn't blow up, but shows this error continuously, even when I run
it for 31 days. Please do let me know if I need to do anything about it, or it
is common with EUL T85, with DTIME = 600.

I have also run the model in the T85 resolution, with SLD dynamical core, with
the default timestep size (DTIME = 1800). This works fine without giving any
errors.

Any pointers in this regard would be of great help.

Thanks,
Saroj

 

[rneale]

This error is common with the Eulerian dynamical and some high wavenumbers are often truncated at high latitudes to satisify the courant limit for advection. It is ok to run with this message printing fairly regular for high latitude grid-points

 

[sandeep_sahany@indiatimes_com]

This error is common with the Eulerian dynamical and some high wavenumbers are often truncated at high latitudes to satisify the courant limit for advection. It is ok to run with this message printing fairly regular for high latitude grid-points

Dear Neale,
Thanks a lot for your zealously help.

regards,
Saroj

 

[san3@meteo_itb_ac_id]

Hi,

I have same problem with eulerian of CAM 3.1 using dataset T85. The running just stop, and give same massages.
:
....
....
COURLIM: *** Courant limit exceeded at k,lat= 5 19 (estimate = 1.354), solution has been truncated to wavenumber 62 ***
*** Original Courant limit exceeded at k,lat= 1 12 (estimate = 2.551) ***
*** Original Courant limit exceeded at k,lat= 2 16 (estimate = 2.112) ***
*** Original Courant limit exceeded at k,lat= 3 17 (estimate = 1.798) ***
*** Original Courant limit exceeded at k,lat= 4 18 (estimate = 1.641) ***
*** Original Courant limit exceeded at k,lat= 5 19 (estimate = 1.354) ***
NSTEP = 3 9.165542745800186E-05 2.842792681902457E-05 253.907 1.01333E+05 2.581399795185573E+01 2.55 2.43
nstep, te 4 3433971087.192234 -102.3013060357173
9.9213356355269369E-003 101333.1087304958
CUBYDR: Departure point out of bounds: jcen,icount,nlon*plev= 11
6652 6656
ENDRUN: called without a message string
Aborted


My namelist :
&camexp
absems_data = '/home/wcpl/work/model/CAMSystem/data/atm/cam/rad/abs_ems_factors_fastvx.c030508.nc'
aeroptics = '/home/wcpl/work/model/CAMSystem/data/atm/cam/rad/AerosolOptics_c040105.nc'
aqua_planet = .TRUE.
bnd_topo = '/home/wcpl/work/model/CAMSystem/data/atm/cam/topo/topo-from-cami_0000-09-01_128x256_L26_c040422.nc'
bndtvaer = '/home/wcpl/work/model/CAMSystem/data/atm/cam/rad/AerosolMass_V_128x256_clim_c031022.nc'
bndtvo = '/home/wcpl/work/model/CAMSystem/data/atm/cam/ozone/pcmdio3.r8.64x1_L60_clim_c970515.nc'
bndtvs = '/home/wcpl/work/model/CAMSystem/data/atm/cam/sst/sst_HadOIBl_bc_128x256_clim_c031031.nc'
caseid = 'camrun'
iyear_ad = 1950
ncdata = '/home/wcpl/work/model/CAMSystem/data/atm/cam/inic/gaus/cami_0000-09-01_128x256_L26_c040422.nc'
nelapse = -365
nsrest = 0
nhtfrq = -24
/
&clmexp
finidat = '/home/wcpl/work/model/CAMSystem/data/lnd/clm2/inidata_2.1/cam/clmi_0000-09-01_128x256_c040422.nc'
fpftcon = '/home/wcpl/work/model/CAMSystem/data/lnd/clm2/pftdata/pft-physiology'
fsurdat = '/home/wcpl/work/model/CAMSystem/data/lnd/clm2/srfdata/cam/clms_128x256_c031031.nc'
/

But I need the model result using data set T85. How could I still running the model?

Regards
San3

 

[san3@meteo_itb_ac_id]

For information I try running with dtime 1200, 600, 300 but the run still aborted. So what should I do to running for this case (aqua planet)?

 

[olson]

try setting divdampn = 1. in the namelist. This will turn on divergence damping for one day and maybe
get you past the initial model shocks.