Versions of ACCESS-CM 2.0 with the atmosphere resolution reduced


A sample of converting an existing ACCESS-CM2 run to N48 resolution is u-bz408. This run was created from CSIRO run u-bm135, similar changes could be made to any of the ACCESS-CM 2.0 experiments to run them at N48 resolution (make sure the source run works on Gadi first).

Consult the diff on Trac for a full list of settings changes

Notable changes to the model are:

  • Land mask and land fraction re-generated by interpolating the ocean mask to the atmosphere grid
  • Orography remade using CAP
  • Enabled default rivstor and rivseq ancillaries
  • Other ancillary files regridded to N48
  • Oasis weight files replaced
  • suite.rc changes to warm starts to allow regridding from N96 runs

Science Changes (make these changes first in 'rose edit', they account for the majority of changes in app/um/rose-app.conf):

  • l_easyaerosol_{lw,sw,zonal} disabled
  • l_adjust_theta disabled
  • l_skeb2 disabled
  • l_ukca disabled

These changes are both for run speed and due to input data needing to be regridded, they can be re-enabled if desired. No other parameters have been changed to account for the difference in atmosphere resolution, checking the scientific stability of the model is recommended, CMS can only verify that it runs.

Ancillary data files were regridded with 'umtool regrid', available in Conda

Performance records are available at

With the default configuration (broadwell, ATM 8x14, OCN 8x12), the model runs at 7.5 model years per day, at a cost of 900 SU per model year

Model output is saved under /g/data/$PROJECT/$USER/archive/$RUNID

ACCESS-CM 2.0 Prototype N48

Rose ID: u-ba839

Science Contacts: Chen Li, Dietmar Dommenget

A prototype version of ACCESS-CM 2.0, with the atmosphere resolution reduced to N48L38

A list of changes from the prototype ACCESS-CM 2.0 run is available on MOSRS at

Data files needed to use the run are stored in $N48_DATA, by default this points to /short/w48/saw562/access2-n48-data