Release notes

These UKCA specific notes should be read in conjunction with the general release notes which are avaialable on the collaboration Twiki. These notes cover changes which have a significant impact on UKCA developers and cover these changes in more detail than the standard release notes

UM 8.5

The first of a series of changes to support the transition from the UMUI to Rose were made at this release. At present, most users should continue to use the UMUI at vn8.5 and vn8.6 but vn9.0 will retire the UMUI. The changes discussed below do not have a significant impact on most users but some are important for those developing new code, especially chemistry scheme which have not yet been lodged.

1. All ukca related input logicals are now read in from the run_ukca namelist including l_ukca, l_ukca_radaer, l_ukca_aie1, l_ukca_aie2 which were previously in nlstcatm.
2. All namelist variables are now given an initial value when declared. See ukca_option_mod.F90

Chemistry namelist changes

1. The namelists no longer contain a separate logical for each chemistry scheme e.g. l_ukca_trop, l_strat etc. These are all replaced by a single integer i_ukca_chem. The meaning of each value of i_ukca_chem is set up in the new module ukca_chem_schemes_mod.F90
2. The original logicals still exist inside the code and are set depending on the value of i_ukca_chem in the new subroutine ukca_setup_chem_mod.F90. It is planned to completely remove the chemistry scheme logicals and replace them with i_ukca_chem at a later date.
3. The number of reactions, number of tracers etc (jpctr, jpspec, jpbk, jptk, jppj, jphk, jpnr, jpdd, jpdw) have also been removed from the namelists and are set up in ukca_setup_chem_mod.F90
4. If adding a new chemistry scheme, simpler hand edits can now be used as there are fewer items to set, but developers must add a magic number for the new chemistry scheme in ukca_chem_schemes_mod.F90 and set the number of reactions etc in ukca_setup_chem_mod.F90

Photolysis namelist change

The separate logicals for the photolysis schemes have been retired and replaced with a single logical i_ukca_photol with magic numbers defined in ukca_photo_scheme_mod.F90

GLOMAP-mode namelist changes

A number of redundant items have been removed from the namelist which either could not be set from the UMUI or had no effect inside the code.