PISCES time step frequency

biogeochemistry
,
1

Hi,

I am assuming that the setting below found in the “namelist_pisces_ref” file containing parameters for PISCES is supposed to give the option to have a different time step (relative to the CROCO time step?) only for the biology model which would be very useful since PISCES slows down the simulation a lot, and biological processes are evolving slower than hydrodynamics so they don’t need such a fast time step. But when I try to set these value to an integer higher than 1 (e.g. 5) the run becomes slower. When I set it to a fraction of 1 (e.g. 0.2) I get an error message.

nrdttrc = 1 ! time step frequency for biology

Any ideas how to use this setting and if it is possible to have a different time step for PISCES than the CROCO time step?

Thanks
Konstantinos

2

hi,
Konstantinos_K
are you talking about MPI. it is not implemented yet. Yes, it will fix when PISCESman completes his work with v2. I can assure you, MPI only.

Alternatively, you can run it on a high memory node like FEM users do with applications such as ADCIRC. I still don’t think it will fix your issues.

3

Hi Konstantinos,

This is something I’ve also tried to adjust as you but same as you, I couldn’t seem to use this setting to make the PISCES timestep larger than the ROMS timestep. I have still been using CROCO version 1.3.1 though. Are you already using the newest version 2.0.0?

As for this issue though, hopefully we can also hear from someone in the PISCES development team for CROCO?

Best,
Lawrence

1 Like
4

Hi, thank you for your reply. No I am not referring to MPI, although MPI seems to work fine for me. I was talking about having a bigger timestep in PISCES comparing to CROCO.

1 Like
5

Hi Lawrence, thank you for your feedback. I am also still working with the 1.3.1 version like you, but I will try version 2.0 just in case it works.

Also, I was thinking if there is an option to run PISCES with a larger timestep offline, after the hydrodynamic simulation on CROCO is complete. There is something like this in ROMS and can be activated with:

define OFFLINE_BIOLOGY

I don’t know if something similar exists in CROCO. Do you know, or any of the developers can give us some feedback?

Regards
Konstantinos