David, Thank you very much.
I follow your two suggestions and re-run my case.
Firstly, I just adjust the dynamics timestep(xndt_dyn), from default 3.0 to 6.0, and I run for one month, it has integrated past this problem. After that,I set the value back to 3.0. Is it ok to do so? one month is enough? Is it possible that I will continue to encounter this situation again?
Secondly,following your later suggestion,I reduce the thermodynamic timestep by changing the coupling frequency to 144 from the default 96, and also xndt_dyn from default 3.0 to 2(to keep the dynamics timestep unchanged).But now it has an error(as follows) about FV dycore timestep, and I changed some values(NSPLIT and NSPLTRAC) as suggested. I run again and now it looks ok(I just started to calculate, and now it is running, not finished). But whether is there any further problem?
Thanks.
the last lines of atm.log.140514-151753
=========================================
FV subcycling - nv, n2, nsplit, dt = 2 3 2 50.0000000000000
ERROR: Because of loop nesting, FV dycore can't use the specified namelist settings for subcycling
The original namelist settings were:
NSPLIT = 11
NSPLTRAC = 5
NSPLTVRM = 2
NSPLIT needs to be a multiple of NSPLTRAC
which in turn needs to be a multiple of NSPLTVRM.
Suggested settings would be:
NSPLIT = 12
NSPLTRAC = 6
NSPLTVRM = 2
============================================= zedong