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JULES v4.2 details

Release Notes

JULES version 4.2 is the first release where all development has taken place in the Met Office collaboration repository. On the whole, this has been a success, with module leaders beginning to use the Trac system to track and approve developments in their areas.

The JULES vn4.2 release consists of 35 tickets from 13 authors across 39 commits.

Science changes

  • TRIP and RFM river routing (see jules_rivers.nml)
  • Incorporation of widely used fire risk indices (see fire.nml)
  • New soil thermal conductivity model that is more appropriate for organic soils (see soilhc_method)
  • Addition of “bedrock” column beneath the soil column, in which only thermal diffusion occurs (see l_bedrock)
  • New canopy radiation scheme in which the nitrogen follows an exponential decay (see can_rad_mod)
  • Updates to trait PFTs (see l_trait_phys) to ensure that the dynamic and equilibrium solutions for vegetation fraction are equivalent
  • Crop model now conserves carbon

Technical changes

  • Added flag to force the model grid to be 1D (see force_1d_grid)
  • Several new diagnostics added (see JULES Output variables)
  • New rose-stem regression tests added
  • All rose-stem tests migrated to use NetCDF and nccmp
  • Retirement of several include files
  • Removal of logging namelist - output location should now be controlled using pipes (i.e. 1>/my/file 2>&1) or features of your mpiexec or mpirun program
  • Additional consolidation of shared (i.e. standalone and UM) control and initialisation routines
  • Optimisation of sf_stom and leaf_limits, resulting in ~20% speedup for can_rad_mod = 4

Bugs fixed

  • Bug in calculation of n_leaf and n_stem in sf_stom
  • Memory overwriting bug in TRIFFID
  • Differing error message lengths in UM
  • hcons now passed to the snow scheme instead of hcon(:,0)
  • Several bug fixes for IMOGEN
  • Patch to enable collective access for parallel NetCDF in NetCDF 4.2 onwards
  • soil_hyd now declares ksz correctly (i.e. ksz(npnts,0:nshyd) instead of ksz(npnts,nshyd)) - this only affects runs where the soil properties vary for each layer
  • Correction to the accumulation of g_leaf_phen in-between calls to TRIFFID

Full details of the tickets committed for JULES vn4.2 can be found on the collaboration repository Trac system.


Building and running JULES v4.2 is described in the JULES User Guide.

Technical documentation is provided by the model description papers referenced in the Publications section of this website.

Source code

The JULES source code is available as a tarball: jules-vn4.2.tar.gz (requires account)

Developers should use the collaboration repository - contact Matt Pryor for access ().