6.5. model_environment.nml

This file sets the model environment options e.g. whether JULES is coupled to the UM or run in a standalone environment. It contains one namelist called JULES_MODEL_ENVIRONMENT.

There are many JULES science options that are in shared namelists, so they can be read both by standalone and by a model driving JULES e.g. the UM. However some options either make no scientific sense or the necessary input data are not available to the environment in which JULES is being driven as the plumbing has not yet been done. This causes problems for example when creating standalone apps from UM configurations. This namelist allows the environment in which JULES is being run to be specified so that options that are unavailable can be made inaccessible via the metadata and thus will not appear in the gui. Warnings can also be issued if options are inappropriately set.

This namelist also describes the flavour of the land surface model being used. CABLE is in the process of being incorporated into JULES and other flavours of JULES is in development e.g. a standalone rivers app.

6.5.1. JULES_MODEL_ENVIRONMENT namelist members


Switch to identify the environment in which JULES is being run. The switch should only be used to allow science options, which are not available in the specified model environment, to be trigger ignored and checked that they are set appropriately at run-time.

0 JULES is being run standalone.
Any options that are only available to the parent model (e.g. the UM) will be trigger ignored.
1 JULES is being run coupled to the UM.
Options not available to the UM are trigger-ignored.


No science code should be associated with this switch, only what science options are available.


The metadata of the parent model only actually allows the appropriate option to be specified i.e. in standalone only 0 is permitted and in the UM only 1 is permitted. Any other parent models are listed here for information only. It is not appropriate to include a list of the unavailable options here. However, information for namelists that have been consolidated will appear in the following checking routines as they are completed.


Switch for land surface model flavour.

1 JULES land surface model
2 CABLE land surface model


The CABLE model has not yet been implemented within the JULES repository.