[MITgcm-support] dumpFreq & MNC package

[Martin Losch]

Laure,

I am not quite sure what the problem is, but the name dumpFreq is a  
bit misleading, it's really the time (in seconds) between "state"- 
dumps. In your data file, you start at t=0 and end at t=7200. seconds  
and you produce output at t=0,3600,7200 seconds, independent of you  
time step.

Does that help?

Martin

On 18 Jan 2007, at 17:19, Laure Grignon wrote:

> Hello,
>
> I'm using the MIT with the MNC package to get a netcdf output. I  
> appear to have the state generated more frequently than set in my  
> data file. It is not the case when the same snapshot is written  
> several times in the state file, because the snapshot is different  
> at each timestep.
> I tried setting dumpFreq to different values, and always get the  
> same problem, even for very short runs. I've checked on the screen  
> output that dumpFreq is actually read as set in the data file, and  
> it is (not only when the data file is first read, but also later  
> when all the parameters of the model are displayed with their  
> values, even the ones not in the data file).
>
> I also tried changing the timestep: no difference. The frequency at  
> which the snapshots are written is not even proportional to the  
> number of timesteps. (which rules out any confusion with the pickup  
> files frequency)
> Although, when I set dumpFreq to 0, only the initial and final  
> states are written, as it should be.
> The most surprising is that I managed to make it run properly  
> before, with some slight changes in the data file.
>
> Does anybody have any idea on where that might come from? Is there  
> a parameter I have neglected/ haven't set properly? Here is part of  
> my data file:
>
> # Time stepping parameters
>  &PARM03
>  nIter0=0,
>  startTime=0.0,
> # nTimeSteps=5040,
>  endTime=7200,
>  deltaT=120,
>  abEps=0.1,
> # create a pickup file each day
> # pChkpt: *permanent pickup file
>  pChkptFreq=86400.0,
> #alternating pickup file: each 1/6th day:
>  chkptFreq=14400.0,
>  dumpFreq=3600,
>  monitorFreq=0,
>  cAdjFreq=-1,
>  periodicExternalForcing=.TRUE.,
>  externForcingPeriod=86400,
>  externForcingCycle=10454400,
>  &
>
>
> Thanks for your help!
> Laure
>
>
>
> ***************************************************
> Laure Grignon
> PhD: Observing the ocean using sub-sea gliders
> Ocean Observation and Climate (566/13)
> School of Ocean and Earth Sciences
> National Oceanography Centre, Southampton
> University of Southampton, Waterfront Campus
> European Way
> Southampton
> SO14 3ZH
> United Kingdom
>
> Tel: +44 (0) 23 8059 9219
> lg804 at noc.soton.ac.uk
>
> ***************************************************
> National Oceanography Centre, Southampton: http://www.noc.soton.ac.uk
>
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