ACCESS 2 Rescalable

ACCESS-CM 2.0, with a changeable atmosphere resolution


  • u-ce694: N216 Historical, based off of u-bm652 (CSIRO Gadi Historical)


The experiment hasn't yet been optimised for performance, please contact CMS before running the model so it can be optimised.

Disabling UKCA chemistry and EasyAerosol aerosols should improve performance at the cost of no longer matching N96 behaviour

Changing Resolutions

In the Rose editor:

  • In um->namelist->Reconfiguration and Ancillary Control->Output dump grid sizes set 'global_row_length' and 'global_rows' to 2*N and 3*N/2 respectively (e.g. for N216 values are 432, 324)
  • In regrid_coupling->namelist->regrid_cm2 set atmosphere_endgame_n to the resolution to use for this run
  • Make sure reconfiguration is enabled

Setting up new experiments

The 'regrid_coupling' task regrids any input files to the target resolution, placing the newly regridded files in 'output_dir'.

  • 'ancils' is UM format ancillary files (e.g. ozone)
  • 'netcdf_ancils' is NetCDF format files (e.g. UKCA emissions)
  • 'set_flexible_calendar' is needed if you get error messages that UKCA oxidant files have the wrong calendar set
  • 'easyaerosol_dir' is the directory with EasyAerosol files, as set in um->namelist->easy_aerosol

The directories for these files in the um section then needs to be changed to the 'output_dir' of 'regrid_coupling', by default this is '$WEIGHTS_DIR' (share/data/weights)

The Oasis file paths shouldn't need to be changed unless the ocean model grid changes

How it works

Task 'regrid_coupling' regrids the original N96 resolution data files to the target resolution, and creates the Oasis weights files for the model coupling

Task 'reconfiguration' regrids the UM astart dump to the target resolution, however it skips the CABLE fields

Task 'regrid_cable' takes the output of the reconfiguration and adds regridded CABLE fields from the original astart file.