1.4. JULES version 4.6 Release Notes

The JULES vn4.6 release consists of 43 tickets from 22 authors across 52 commits.

Full details of the tickets committed for JULES vn4.6 can be found on the JULES shared repository Trac system.

1.4.1. Science changes

• Multiple ice tiles in a gridbox to simulate snowpacks at different elevations - see l_elev_land_ice
• Modifications to snowpack physics to better represent deep, compact firn/snow on ice sheets - description at l_elev_land_ice
• Option to link whole-plant maintenance respiration to soil moisture stress - see l_scale_resp_pm
• Read clay content of soil for soil carbon decomposition model from ancillary file - see JULES_SOIL_PROPS
• Improved climate downscaling physics for ice elevation tiles
• Calculate FAO Penman-Monteith evapotranspiration for reference crop - see diagnostic fao_et0
• Diagnostic form drag for sea ice (UM only)
• Calculation of new sea ice variables required for CMIP6
• Implement a canopy clumping factor - see can_struct_a_io
• Allow for non-istropic scattering in plant canopies - see l_niso_direct
• Increased flexibility to represent soil moisture stress on vegetation - see fsmc_mod_io and fsmc_p0_io
• Improved parameterisation of crop leaf senescence
• New crop harvest diagnostics
• Lake model FLake beneath multi-layer snow (UM only)

1.4.2. Technical changes

• JULES-C-1p1 Regression Tests
• Remove the UM_FLAKE CPP macro
• Move sorp and n_inorg_turnover to namelist to enable user input.
• VM rose stem bug fixed.
• Add support for rose-stem on MONSooN
• Move some of the hard-wired crop parameters to JULES_CROPPARM
• Remove UM descent.h include file and put values into JULES module descent.F90
• Fix race conditions and improve OpenMP DEFAULTs
• Modularise and header refactor science/snow

1.4.3. Bugs fixed

• Fixed GC3 tstar_sice bug
• Corrected canopy nitrogen profiles - see l_leaf_n_resp_fix. This increases plant maintenance respiration.
• Reduced stem respiration with trait-based physiology
• Reinstated missing veg parms, for trait initialisation.
• Soil respiration bug resolved
• Corrected mistake in merging of crop PFT changes
• Fixed N diagnostic to avoid runtime crashes
• Fixed calculation of dust deposition exchange coefficient
• Fixed wetland emission of methane with TRIFFID on
• Fixed aerodynamic resistance diagnostic (UM diagnostic)

1.4.4. Documentation updates

Coding standards, and documentation can be viewed on the ‘github page <http://jules-lsm.github.io/>_’.