GENIE:FAQ

How do I work out a timestamp from the timestep?

 * E.g. I want to run a long simulation and need to break it into a series of short runs. To automate the process I need to work out what the timestamp of each final output restart file will be so that I can feed this file into the next execution. There is clearly a simple formula relating koverall_total, nyear, yearlen and maybe others to the timestamp/label that will be attached to the restart file. What is it?

How do I get daily / monthly / yearly / decadal output?
Ans (Bob Marsh): N.B. all of these frequencies are in ocean timesteps
 * I do not fully understand the parameters npstp, iwstp, itstp, ianav and what they control
 * npstp = frequency of 'health checks', written to screen or directed to file
 * iwstp = frequency of 'restart' datasets (ascii or netcdf format) containing all prognostic variables, written as a snapshot, usually at 'midnight Jan 1st'
 * itstp = frequency of 'time series' datasets (e.g., hemispheric mean temp, Atlantic overturning intensity), written in ascii format
 * ianav = frequency of 'annual average' datasets (ascii or netcdf format), averaged over an integer number of years

How do I reduce the timestep?
Ans (Bob Marsh):
 * I have encountered numerical instability and would like to reduce the timestep but keep e.g. yearly output
 * If using GENIE-1: Numerical instability is usually manifest in failure of the iterative procedure we use to solve for sea ice temperature. Try halving the timestep by either: (a) doubling the number of EMBM timesteps per ocean timestep (ea_10, from default 5 to 10); (b) doubling the number of ocean timesteps per year (remember to change go_9, ea_9 and gs_9 identically). To keep yearly output (in time series files), change itstp likewise (go_5, ea_5, gs_5).
 * If using GENIE-2: Consult IGCM people

How do I change the calling frequency of a component?

 * Help

How do I restart a GENIE model?

 * GENIE-1 (this seems to work)
 * data_genie
 * lrestart_genie=.TRUE.
 * data_EMBM, data_GOLD, data_SIC
 * ans=c
 * netin=y,
 * filenetin="goldstein_restart_1999_12_30.nc"
 * data_LAND
 * l_restart=.TRUE.
 * c_restart="land_rs_00500000.nc"


 * GENIE-2 (example config files are available)