Bugfixes (new approach)


The aim of this page is to present the information on the new bug reporting system. All bugs should be reported to ukca_bugs@metoffice.gov.uk. More details of the approach to reporting and fixing bugs is contained in the document here .

Bug fixes table

This is a list of all reported bugs, with a link to tickets with more information on the issue and branches to fix it. Some of the bugs/ issues are described in more detail on an older bugfixes page. The UM versions listed are those where the bug is known to be present. Please note however, that bugs in versions before 8.2 are not reported here, although information on some of these can be found here.

# Description Ticket Affected
Branch with fix Remarks OPEN/CLOSED Owner
1 Improper construction of filename
for Background Aerosol data used for Fast-JX/ HetPSC
#4283 #439 8.2-8.3 MetO:
Lodged at UM8.3.
Note: Likely to clash with
some vn8.2 science branches.
2 SO3 missing from UKCA_CSPECIES
3 MODE diagnostics indexing issue
4 Correct the methane initialisation
when l_prescribe_ch4 option is selected
5 Logic for Heterogenous reactions under TropIsop Chem
6 String length differences in Strat+Trop
reaction rate definition array
7 Incorrect Loop control for a Fast-JX routine
8 Remove N2O from lumped N species for Stratospheric Chemistry
9 Fix an initialisation issue that caused
consecutive runs to give different results
10 Incorrect read-size for a Fast-JX lookup table
11 Minor write statement formatting issues
12 Minor variable/ array initialisation issues.
13 Missing initialisation of COS LowBC #4956 #651 8.2
Lodged at UM8.2 CLOSED -
14 UKCA Age-of-Air setup bug #5175 #636 8.2-8.5
Lodged at UM8.5 CLOSED -
15 Incorrect factors for MODE emiss diagnostics Part of
#636 8.4-8.5
MetO: Included in
Lodged at UM8.5 CLOSED -
16 Array Dimensioning/ Indexing issues
affecting ENDGAME
#5420 #636 8.4-8.5
Lodged at UM8.5 CLOSED -
17 Activate: Value underflow trap combined with debug-level Part of
#636 8.2-8.5
MetO: Included in
Lodged at UM8.5 CLOSED -
18 Errors in UKCA CheST+Het/PSC setup code #5465 #652 8.5

Lodged at UM8.5 CLOSED -
19 Change in UKCA results when
print/ debug level is changed
#5470 #636 8.2-8.6
Lodged at UM8.6 CLOSED -
20 Failures in asad_chem_diags when
Print-level=Diag and using UmPrint
as Asad debug output exceeds buffer size
Part of #5470 #650 8.6 MetO: Included in
Lodged at UM8.6 CLOSED -
21 Incorrect calculation of some ASAD 3-D diags #5922 #636 8.2-8.6 MetO:
Lodged at UM8.6 CLOSED -
22 Indexing bug - sin_v_latitude Part of
#636 8.5
MetO: Included in
Lodged at UM8.5 CLOSED -
23 Bug in Fast-JX mass calculation #5404 #565
Also #636


Seems to mostly affect
Low-top or hi-res runs.
Lodged at vn9.0
24 Erroneous 50% reduction factor in
aerosol sedimentation velocity calc
Part of #6105 Part of #647 8.2:
MetO:Included in


Lodged at vn9.0 CLOSED -
25 ACTIVATE uses saturation mix ratio instead
of saturation vap pressure
Part of #6105 #636 8.2:


Puma: Included in
Lodged at vn9.0 CLOSED -
26 TropChem: uses mmr instead of vmr for Q Part of #6105 #636 8.2:

Puma: fcm:um_br/dev/mdalvi/vn8.4_ukca_fixes_from_vn86
Lodged at vn9.0 CLOSED -
27 Erroneous reaction rate for OH+MGLY reaction Part of #6105 #636 8.2: MetO: For StratTrop/CheST

for TropIsop Included in:

Puma: For StratTrop/CheST

For TropIsop/CheT: Included in

Lodged at vn9.0 (StratTrop only) CLOSED -
28 Indexing bug - all_tracers array
in Plume Scavenging branch
Part of #6105 None 8.4:
EG+Plume Scav
MetO: Included in
Lodged at vn9.0 CLOSED -
29 Indexing bug - asad_chemdiags%diag_type in asad_tendency_ste Part of #6105 #636 8.2: MetO: Included in

Puma: fcm:um_br/dev/mdalvi/vn8.4_ukca_fixes_from_vn86
Lodged at vn9.0 CLOSED -
30 Indexing bug - f3_at_u Part of #6105 #636 8.4:
MetO: Included in

Puma: fcm:um_br/dev/mdalvi/vn8.4_ukca_fixes_from_vn86
Lodged at vn9.0 CLOSED -
31 FP exceptions in asad_sparse_vars
or asad_spimjmp
#555 7.3:
Temporary Work-around.
May not work in
all cases
CLOSED as not seen any more. May re-open
CLOSED Nick Savage
32 ACTIVATE:uses cloud_liq_water (diagnostic) which is
not consistent with cloud fraction (prognostic)
Part of #6105 #636 7.3:

Lodged at vn9.0 CLOSED -
33 RADAERv2 in UMUI: Look-up table files linked to wrong Unit numbers None None 8.5-8.6 Enter _an_ files for accumulation mode
and _ac_ files for the
aitken/insol accum mode boxes
on the RADAER panel
No code change involved CLOSED -
34 ACTIVATE: Argument dimensions not compatible with ENDGame
(should specify 1:model_levels)
Part of #6105 #636 8.5:
MetO: Included in

Lodged at vn9.0 CLOSED -
35 Error in labelling: Surface resistance <--> stomatal resistance ? #6417
#653 7.3: None Will be folded into larger dry deposition work plan OPEN Fiona O'Connor
36 Error in calculation of Column Ozone diagnostic UM:#102
7.3: MetO:

Lodged at vn10.1 as part of the
UKCA bugfix package vn10.1_ukca_bugfix_package under ticket UM:#564
37 Mismatch in levels for UKCA non-transported prognostics/ chem_diags.
Dimensions not compatible with ENDGame
#6376 #649 9.1
Lodged at vn9.1 CLOSED -
38 Missing logical for volcanic so2 emissions. UM:#1350
#656 MOSRS:
Lodged at 10.6 CLOSED Mohit Dalvi
39 Fast-JX fails if .NOT. L_PC2 and .NOT. l_3d_cca #6443 #667 8.2-9.1 MetO:
Lodged at vn9.1 CLOSED -
40 UKCA fails if MODE switched Off
10m wind not in D1 but req for AeroChem
Part of
9.1 UKCA+AeroChem;
Lodged at vn10.0 CLOSED -
41 OC biomass burning emissions - incorrect
conversion. Assumes emissions as kg POM, but (new)
ancils are kg C
#6429 vn8.5: MetO:

The scaling up of OC to POM is now expected to be done when creating the ancils. In the netcdf system the units (i.e. OC or POM) will be explicitly given in the meta data to avoid this problem. CLOSED -
42 RADAER lookup table reading bug.
Input values not passed to RADAER
part of MOSRS UM:#112
Lodged at vn10.0 CLOSED -
43 Reconfiguration bug. L_UKCA used for
setting tr_levels before RUN_UKCA is read
vn8.3:vn9.0 UKCA with
Classic fully Off

Automatically fixed under STSHCOMP
rationalisation at vn8.6 (#5331)
44 Logicals set to default TRUE:
l_ukca_ibvoc: aborts if JULES copy is not set.
l_ukca_plume_scav: non-GLOMAP (e.g. Age-Air only) run crashes.
part of MOSRS UM:#112 vn9.2: UKCA MOSRS:
Lodged at vn10.0 CLOSED -
45 nlev is not passed to asad_impact in asad_cdrive UM:#252 All versions MOSRS:
See MOSRS ticket UM:#252. Lodged in vn10.0. EXBUG from NCI. CLOSED -
46 Inconsistent use of wet_levels and model_levels
in UKCA_AERO_CTL 1-D arrays
None All versions None Impact if wet_levels/= model_levels, but
this option has never been supported for New Dynamics or ENDGAME and
wet_levels is being retired by UM:#425 from 10.2.
47 Dimension mismatch: q_chem, t_chem not
considering extra level for ENDGame
UM:#379 ENDGame-UKCA Example fix here (MOSRS) Lodged at UM10.1 as
part of UM:#239
48 Bugs in RADAER - dimensions, asymmetry param UM:#380 UM:#564 All RADAER Example fix here (MOSRS) and here (MOSRS) Leads to div-by-zero error in rescale_phase_fnc.
Lodged at UM10.1 as part of the UKCA bugfix package
under ticket UM:#564
49 UKCA emissions: incorrect number,
un-initialised slots in all_emissions()
UM:#381 All UKCA Example fix here (MOSRS) Lodged at vn10.2 as
part of UM:#805
CLOSED Mohit Dalvi
50 ukca_solve_coagnucl failures UM:#319 UKCA-GLOMAP Example fix here (MOSRS) Mainly a workaround
To be lodged
CLOSED Mohit Dalvi/Graham Mann?
51 Units of wetland emissions UM:#571 All versions Example fix here (MOSRS) Wetland emissions misinterpreted as
gridbox mean rates rather than a land
fraction rate - Lodged at UM10.1 as part of the
UKCA bugfix_package under ticket UM:#564
52 PSC surface area set to zero? UM:#609, UM:#595 UKCA with l_het_psc Lodged at UM10.4
595 corrects GLOMAP aero surf area units,
609 corrects logic for using Clim/CLASSIC/GLOMAP aero surf area
CLOSED Mohit Dalvi/ Luke Abraham
53 UKCA RADAER namelists aren't read on the Cray UM:#577 RADAER, some platforms only Change to input files, not code
M. Richardson to share info on back porting'
Files have been edited after vn10.1 by Sytems Team : for older versions here is a Namelist workaround CLOSED -
54 Offline oxidants Chemistry:
Diagnostics not properly initialised
UM:#659 Offline Chem vn10.3.1_ukca_correct_oxidants Lodged at UM10.3 Closed
55 Use of trigonometric variables e.g. f3_at_u
not consistent with ENDGame
UM:#658 All UKCA vn10.2_ukca_bugfixes_package Lodged at UM10.2 as part of #805 CLOSED Mohit Dalvi
56 Array size issues with UKCA tracers when using EG limited area models UM:#682 ENDGAME UKCA LAMs MOSRS:
to be lodged at UM10.2 lodged at UM10.2 CLOSED -
57 Incorrect logic for DMS anciliaries required UM:#756 UKCA jobs not using
CLASSIC but without DMS in chemistry
Model stops with message about
missing input. Low priority - rare edge case with informative error message.
See UM:#2814.
CLOSED Nick Savage
58 Fastj-X runs on patches all in dark UM:#1360 UKCA jobs using FastJ-X None yet Optimisation not bug. Ticket stays open but does not belong here CLOSED Nick Savage
59 Mismatch in levels while reading
CDNC from D1 under ENDGame
UM:#704 EG-UKCA vn9.0+
with Indirect effects
MOSRS: vn10.0_fix_cdnc_lev Lodged at UM10.2 CLOSED Mohit Dalvi
60 Model failure with PrStatus_Diag UM:#784 UKCA on Cray MOSRS: vn10.2_ukca_prstat_diag_fixes Lodged at UM10.2 CLOSED Mohit Dalvi
61 MPI BCAST bug in NetCDF emiss code UM:#782 vn10.1 UKCA
with Netcdf emiss
MOSRS: vn10.2_ukca_netcdf_bcastbug Lodged at UM10.2 CLOSED Mohit Dalvi
62 Inconsistency in aero_surf area used in
heterogeneous reactions routine
UM:#778 UKCA+ het Fixed as part of #98 (non transported prognostics Closed
63 Inconsistency in timestep/ interval
calculation for BE-Offline scheme
UM:#774 All BE Offline vn10.2_ukca_repair_interval Lodged at vn10.2 CLOSED Colin Johnson
64 Very low cloud fraction values
can cause failures in Fastj/jx
UM:#757 Any Temporary fix:
Temporary workaround
lodged at vn10.2
65 qcl not correctly initialised
in ukca_calc_aqueous_6a
Part of UM:#805 UKCA run with
6A convection
MOSRS: vn10.2_ukca_bugfixes_package Lodged at UM10.2 CLOSED Mohit Dalvi
66 Crash in NetCDF emissions and oxidants routines
when using NetCDF-4 libraries
NA vn10.0-10.2 UKCA
+ NetCDF
MOSRS: vn10.2_ukca_readnc_offline_fix Automatically fixed as part of UM:#282 CLOSED -
67 Error in indexing of Radiative gases array.
Radiation sees MMR of the wrong ('next') species
UM:#1150 All EG-UKCA with
gas-radiative feeback
MOSRS: vn10.2_grgas_addr_fix Lodged at UM10.3 CLOSED Marc Stringer (UKESM)
68 HO2 heterogeneous loss rate 1st order(?) No ticket No ticket Strat-Trop and Tropisop with l_ukca_trophet=TRUE None This may be correct CLOSED Nick Savage
69 Inconsistency between aerosol size and mmr/Nd.
wetdp and drydp not recalculated after aerosol remoding
UM:#1089 ALL UKCA- GLOMAP. MOSRS UM10.2: vn10.2_ukca_wetdp_drydp_recalc_bug
[MOSRS UM10.3: vn10.3_ukca_wetdp_drydp_calc_fix
Leads to unphysical large spikes
in AOD. Believe UM7.3 jobs may be
unaffected but haven't checked.
Lodged at UM10.4
70 Age-of-air only configuration does not work at UM10.3 part of UM:#1171 UM10.3 Age-air-only MOSRS: vn10.3_ageair_and_minor_fixes Lodged at UM10.3 CLOSED Mohit Dalvi
71 Minor bugs flagged up by rigorous compilation flags:
dust_flux: array not allocated if L_dust=False, but passed regardless to ukca_new_emiss_ctl
soil_layer_moisture: first dimension=0 if no land on PE.
advt(): variable used in loop over total tracers when size is jpctr (=chem_tracers).
nldepx: out-of-bounds with Offline oxidants scheme. Size of array
should be 6+jpspec, based on information from ASAD developer.
UM:#1171 UKCA+NetCDF emiss MOSRS: vn10.3_ageair_and_minor_fixes Lodged at UM10.3 CLOSED Mohit Dalvi
72 UKCA Dry Deposition: Surface resistance values
not set for some species
UM:#1250 UM7.3+ MOSRS: vn11.0_surface_resistance Lodged at vn11.1
Follow-on ticket to remove temporary logical (l_fix_improve_drydep) UM:#3997
73 UKCA-GLOMAP: MDT< MDTMIN warnings from GA6+ runs UM:#1251 UM7.3+ None yet To be Lodged CLOSED - see UM ticket UM:#1332 Graham Mann
74 Bug in ukca_tropopause with definition of PV tropopause
Fix to be combined with Bug 75 below
New ticket UM:#1367
UM10.3 MOSRS: vn10.6_ukca_tropopause_amendment Scope extended to include modifications to print statement. To be Lodged, but isn't sufficient to fix STE flux diagnostics
Lodged at vn11.2
CLOSED Mohit Dalvi
75 Bug in STE fluxes UM:#1367 ENDGame? vn11.1_ukca_fix_o3_ste Lodged at vn11. CLOSED Mohit Dalvi
76 Scale Lightning emissions UM:#1310 UMvn7.3+ vn10.2_scale_lightning_nox works but scaling is to be added as namelist variable for lodging purposes Lodged at 10.5 CLOSED -
77 Bug in microphysics process rates used by GLOMAP which leads to process rates being ~O(10) times too low and hence too small aerosol removal. The aerosol removal has to be tuned in response to this bugfix bugfix: UM:#367 Tunings: UM:#854 GA4 + Configs [tunings applied in GA7 development +) Bugfix: vn10.2_mphys_bugs_improvements
Tunings: vn10.2_ukca_asnow_rfrac_tune

Bugfix and Tunings backported to PUMA br at UMvn8.4.
Bugfix: mdalvi/vn8.4_mphys_bugfix
Tuning: j.mollard/
[revision 20160]
Both Lodged from UM10.3 CLOSED Jonathan Wilkinson/Jane Mulcahy
78 GLOMAP dust bugs:
1. Mapping of bin->mode emissions
2. incorrect STASH options codes
UM:#1355 UM10.2:, GLOMAP
with dust
vn10.3_ukca_dust_diag_emis_fixes Lodged at UM10.3 Closed Stephanie Woodward
79 Aerosol Impaction scavenging bugs:
1. Incorrect use of Conv Frac (FC)
2. Total (conv+dyn) precip rate applied separately for convective as well as dynamic scavenging (double counting)
Retire logical at UM:#4145
vn7.3: GLOMAP vn10.3_ukca_impscav_fix
Lodged at UM10.3
Target UM11.2
Closed Stephanie Woodward
Alan J Hewitt
80 H2O feedback broken under ENDGAME UM:#1646 All EG jobs with H2O feedback? None In progress CLOSED Colin Johnson
81 Runs with segment/ restart interval < 5 days
fail due to NetCDF emiss update bug
UM:#948 but to be fixed under
UM10.2+ , NetCDF emissions Temporary workaround:
2. Use NetCDF emissions from /projects/ukca-meto/mdalvi/ancil/daily
Lodged at 10.6.1 CLOSED Alistair Sellar/ Mohit Dalvi
82 Incorrect arguments to ukca_calcminmaxndmdt.F90 UM:#1801 10.2 - 10.4 r21272 of vn10.4.1_ukca_refactorings Causes extra output from some PEs. Does not change results. to be lodged with other refactorings CLOSED -
83 error in the indexing of the tot_tracer array in the convective plume scavenging UM:#2036 ? - 10.5 r21272 of vn10.4.1_ukca_refactorings the number tracer for the first active mode will not be scavenged and there will be plume scavenging happening to the passive ozone or age of air tracer if using a chemistry scheme with l_ukca_advh2o TRUE. Fix lodged at 10.6 CLOSED Nick Savage
84 NetCDF error when using UKCA and Nudging: Model fails with 'EM_GET_VAR_INFO: Time dimension info not found, check if em_fopen was called with option l_ignore_time = .TRUE.' UM:#2095 10.2 onwards;
Includes other Nudging bug-fix and
new rose-stem app
Lodged at UM10.5 Closed Mohit Dalvi
85 Failure if using UKCA as Age-air-only
Error: "Type of solver (0) not recognised" (as this config does not use any chemical scheme)
UM:#2148 10.5 Age-air-only
e.g. GA7 w/o GLOMAP
vn10.5_ukca_ageair_fix Lodged as part of #1232 at 10.6.1 CLOSED Mohit Dalvi
86 Discontinuity in photolysis diagnostics UM:#2286 At least UMvn10.5 Fixed as a side effect of #1958 CLOSED Fiona O'Connor
87 Possible issues with YSTORE in UKCA_CHEMISTRY_CTL. This may mean than there is no H2SO4 because of this, with impacts on GLOMAP aerosols. Need to also select the correct products in chemistry_ctl UM:#3245 vn8.2+ Combination of two different bugs - see
Lodged at vn11.3 CLOSED Luke Abraham
88 Potential FastJX Scattering Bug UM:#3261 vn7.3 onwards vn10.6.1_fastjx_scattering_fix
Lodged at vn10.9 CLOSED David Wade/Luke Abraham
89 Sea Salt Density UM:#2405 vn7.3 onwards vn10.8_ukca_ss_density_correction
Lodged under a temporary logical at UM10.9 (so not on by default) "l_fix_nacl_density" in namelist:temp_fixes
UM:#3490 follow up ticket will review temp logical.
CLOSED Colin Johnson
90 Extremely high/low NOy concentrations UM:#3400
vn7.3 onwards (at least) vn10.8_ukca_nat_fixes Will be fixed for vn10.9. Runaway HNO3 values at the surface due to BL NAT sedimentation lead to global corrections during transport, leading to large stratospheric loss with knock-on impacts to O3 and ClONO2 etc. CLOSED Mohit Dalvi/Luke Abraham
91 N-R offline oxidants broken at UM10.9 and a missing k index UM:#3606 vn10.9 for break
and vn9.1 for k index
vn10.9_fix_offline_oxidants Lodged at UM10.9 CLOSED Marc Stringer
92 UMDP084 incorrectly labels 38-476 ("Liquid cloud fraction") with units "m-3". It is a pure fraction (in the range 0.0 to 1.0) and so has no unit. UM:#3025 Lodged at UM11.1 CLOSED -
93 Inconsistent surface resistance values for organic hydro-peroxide (rooh) UM:#1250 Unknown vn11.0_surface_resistance Lodged at vn11.1
Follow-on ticket to remove temporary logical (l_fix_improve_drydep) UM:#3997
94 Data corruption in Age-of-Air (and possibly Passive O3) diagnostic on pressure levels UM:#3718 vn10.2+ vn10.9_ukca_debug_ageair_on_plev
Lodged at UM11.0 CLOSED Mohit Dalvi
95 wet/dry deposition flags for ozone are not consistent This is a feature not a bug. CLOSED -
96 Output drydiam diagnostics where l_ukca_arg_act but not l_ukca_radaer UM:#3962 Unknown The beginnings of a solution are found in vn11.0_ukca_drydiam_act_wo_radaer. Closed as a feature.
This problem has been solved for the aerosol climatologies (see ticket UM:#3874) which use stash addressing rather than d1 addressing.
Work will begin after re-factoring of UKCA stash handling in UM:#4367
as feature
Alan J Hewitt
97 "magic" numbers incrementing imode (e.g. . imode+4 , imode-4 , imode+3 , imode-3 )
See e.g. src/atmosphere/UKCA/ukca_calc_coag_kernel.F90
UM:#4284 Unknown Not a bug:
"For the coarse soluble mode (imode=4) there is no larger soluble mode and also there is no larger insoluble mode. It is intended that, for that mode, there is no intra-modal coagulation with other modes."
98 Incorrect usage of npft integer when npft == 9 OR 13 UM:#4157 All versions with these options vn11.1_fix_npft Lodged at vn11.2
Follow-on ticket to remove temporary logical (l_fix_ukca_h2dd_x) UM:#4245
CLOSED Alan J Hewitt
99 UKCA dry deposition ukca_aerod.F90 HBr HOBr HCl HOCl UM:#4312 vn7.3+ vn11.1_dry_dep_species Lodged at vn11.2
Follow-on ticket to remove temporary logical (l_fix_improve_drydep) UM:#3997
CLOSED Alan J Hewitt
100 Negative concentrations of pvol_wat() UM:#4383 Unknown vn11.2_fix_neg_pvol_wat Lodged at vn11.2
Follow-on ticket to remove temporary logical (l_fix_neg_pvol_wat) UM:#4416
CLOSED Alan J Hewitt
101 Errors in reaction rates and diagnostics UM:#4466 Unknown NA OPEN Scott Archer-Nicolls
Luke Abraham
102 Error in RESHAPE (size 3rd dimension)
in ukca_main before
CALL lsp_qclear
UM:#4595 NA vn11.2_fix_ukca_reshape Not a bug
Testing indicates that KGO change owing to refactoring results from compiler optimisation
Closed Alan J Hewitt
103 Incorrect indexing of tmprc array: ASAD_SPIMPMJP UM:#4562 All versions Possible fix mentioned on ticket To be Lodged CLOSED Luke Abraham
104 Incorrect value for Rc for SO_2 deposition to open water ~~UM:#4635~~
vn vn11.0_Ocean_depo_tweaks To be Lodged Closed Catherine Hardacre
105 segmentation fault on ukca_plev_diags_mod.F90 UM:#4625 Unknown vn11.2_ukca_cce_87 Ticket lodged for UM vn11.3 Closed -
106 NaNs appearing when new UKCA science is turned on UM:#4397 Since vn11.1 vn11.3_ukca_exp_rose_stem Lodged at vn11.4 CLOSED Luke Abraham
107 Missing c_h2o conversion factor in offline_oxidants_be um:#4714
vn11.1_offline_ox_solver_investigation Code is zq(:)=RESHAPE(q(:,:,k),(/theta_field_size/)) rather than zq(:) = RESHAPE(q(:,:,k),(/theta_field_size/))/c_h2o Closed Luke Abraham
108 Incorrect stash processing of GLOMAP load*, conc* and plume_scav diagnostics UM:#4909 UM10.6.1+ None yet To be Lodged after 11.6 CLOSED Mohit Dalvi
109 Bug in dry deposition of CH4 for 13/17/27 tiles UM:#4913 UM10.4+ None yet To be Lodged after 10.6
Gerd noted unusual CH4 output in CMIP6 runs.
May need a rose stem test for H2 and CH4 drdydep code lodged at UM:#4157
OPEN Gerd Folberth
110 UKCA solar-cycle routine does not pass NRUN-CRUN test UM:#4828 UM10.8+ vn11.3_ukca_solcyc_nruncrun To be Lodged after 11.5 OPEN Luke Abraham
111 Cloud fraction array (cloud_frac) passed with wrong number of levels
Array passed as (row_length, rows, :), so offset by 1 level under ENDGame
Part of UM:#4822 All ENDGame versions vn11.3_ukca_fix_cloudfrac_dim To be Lodged for 11.5 Closed John Hemmings
112 delh2so4_chem is calculated incorrectly
Incorrectly "fixed" in UM:#3245 (Bug #87).
UM:#5076 All StratTrop+GLOMAP versions post vn8.2. Made worse post-vn11.4 if logical l_fix_ukca_h2so4_ystore is True. vn11.4_ukca_ystore_fix To be Lodged for 11.6 Closed Luke Abraham
113 Latitude bugs affecting LAM configurations UM:#5119 Unknown None yet To be lodged for 11.6 Closed John Hemmings
114 Bug in ukca_activate leading to droplet numbers being too high in the upper regions of continuous cloud columns um:#5233 r70341 Previously the number per m3 was replicated upwards from cloud base, but really this should be the number per kg of air to mimic what would happen in a rising air parcel (parcel expansion would lead to the number per m3 reducing with height as an air parcel rises, scaling with the air density). This is likely to make the largest difference for deep clouds where there are deep contiguous columns. Closed Dan Grosvenor
115 Some UKCA-related variables accessed in other parts of UM remain undefined in non-UKCA configurations
Was Suite that does not call GLOMAP mode setup
UM:#5151 Unknown None yet To be lodged for 11.6 Closed Mohit Dalvi
116 Problem with the "specific humidity change from UKCA" diagnostic (stashcode 50240) UM:#5164 UM:#3875 Unknown None yet See information in UM:#4819 Closed
117 Fix call to extract_seg and insert_seg in ukca_aero_ctl UM:#4954 10.7+ None yet See both scitech and code review of UM:#4739 Closed - not a bug
118 lam should be REAL in acsn2o5_mod.F90 UM:#5271 Unknown Fix is trivial Requires testing
will result in KGO change
119 Incorrect calculation for gridbox area - only affects GLOMAP-mode diagnostics um:#5506 ALL versions None yet Calculation of volume appears correct, but area is not. This calculation is missing the factor fv_cos_theta_latitude so will not cause area to tend towards zero at the poles. It also seems to use an unnecessary approximation to the latitude difference (based on sinv_latitude) which may break down at high latitudes. The calculation should perhaps be consistent with subsequent volume calculation but without the delta_r factor. This will likely only affect diagnostics calculated in ukca_emiss_diags_mode, where it is used to convert from kg/m2/s to mol/gridbox/s, although it is also printed out in ukca_aero_ctl. OPEN
120 nrsteps warning message - eg um_n48_ga_amip_exp UM:#5505 Unknown Perhaps this should have a clean fail rather than warning? There may be a lot of rose-meta and code changes to allow nr_steps to be set in niche cases. Closed Mohit Dalvi
121 Missing ']' in STASHmaster-meta.conf entry for new item `34871` UM:#5483 UM11.6 trivial Does not affect Rose/STASH working, but prints warning in terminal Closed Marc Stringer
122 O(1D) is calculated incorrectly as a steady-state species UM:#5525 UM11.6 trivial Only affects the diagnostic. Values are a factor of 3 too large Closed Luke Abraham
123 ACTIVATE scale-invariance problem UM:#5532 UM11.6 More of an issue for LAMs. Small effects for climate simulations. Closed Hamish Gordon
124 H2 and N2 cannot be set for RCP and WMOA1 scenario routines UM:#5620 All versions Values are hard-wired in the code and cannot be changed without a branch OPEN Mohit Dalvi
125 Technical/ Rose-stem : ignore-missing flag applied to all Strattrop/CRIstat rose stem tests (instead of just NRUN-CRUN ones). UM:#5752 UM10.9+ This is likely to have missed differences in the number of output fields under subsequent changes CLOSED Mohit Dalvi
126 Fast-JX: Double counting of earth-radius in calculation of spherical mass-weighting factors. (Routine fast-jx_sphere) UM:#5760 All versions Lodged at UM11.8 CLOSED Mohit Dalvi
127 GET_EMDIAG_STASH: Return value from function can remain unset Lodged as Part of UM:#5555 All NCDF emiss versions No value expected for aerosol emissions, but variable remains unset. CLOSED Mohit Dalvi
128 Bug in UKCA stratospheric chemistry diagnostics UM:#5839 pre-UMvn10.0 The indexing/values of diagnostics m01s50i101-i104 are incorrect. Fixes provided for vn11.1 and vn11.7. May affect CMIP6 diagnostics OPEN Luke Abraham
129 Warning messages in ukca_radaer_lut_in UM:#5918 All versions Code does not crash or clean fail
insetad runs until wallclock runs out
Easy to change to clean fail but need
to work out if all should be changed.
OPEN Alan J Hewitt
130 Bug in aerosol dry deposition when using 27 surface types in JULES Parially fixed using UM:#5622 All versions The bug exists because of an erroneous dependency on the array size NTYPE (from JULES_SURFACE_TYPES_MOD) in subroutines UKCA_DDEPAER and UKCA_DDEPAER_INCL_SEDI. This is not appropriate because most of the processing is not written to be dependent on the surface types being used in JULES. A surface type at each location is instead inferred (in UKCA_AERO_CTL) from the roughness length and its index is held in the array ILSCAT. The index values are intended to be interpreted with reference to the JULES 9 type scheme. Only the values 1, 3, 7 and 9 are used, corresponding to forest, grassland, water and ice respectively. The indices are used to access arrays YR, CR and ALPHA that are set up in these aerosol dry deposition routines. The arrays should therefore always be of size 9 with values based on the 9 type scheme, irrespective of the JULES NTYPE value. However, alternative, incompatible arrays are set up if NTYPE is 13, 17 or 27. These were presumably intended to be accessed using the type indices consistent with the other JULES schemes but are actually accessed with the 9-type scheme indices available in ILSCAT. Inappropriate values will therefore be obtained when NTYPE is not 9.
Note that Ticket UM:#5622 will fix the bug when interactive dry deposition is not used in the chemistry or when NTYPE in JULES is 13 or 17 but will not fix it when interactive dry deposition is selected (L_UKCA_INTDD = .TRUE.) and NTYPE is 27. Fixing it for NTYPE = 27 will change results so will require a separate bug fix ticket with appropriate testing and approval.
131 Invalid surface roughness input to aerosol dry deposition over land All versions In the UM, UKCA uses the roughness length with stash code 00026 to infer the surface type for aerosol dry deposition (and for the old non-interactive gas dry deposition scheme). However, this value is only valid over the sea. It seems to be set to 0.5 over the land from the UM data I’ve looked at. This seems to be simply a filler value with no scientific significance. As a consequence of the 0.5 value, the UKCA aerosol dry deposition routines categorise all land as forest in the UM runs (routine ukca_aero_ctl uses z0>0.1m for forest). This will interact with bug #130 in aerosol dry deposition (see above) that occurs when using any number of surface types in JULES other than 9. OPEN

Package branches table

For every supported version, the aim will be to have a package that fixes all bugs known to exist at that UM version. The package will be supported on both the NCAS and Met Office repositories (until a single repository is created)

UM Versions Ticket Package Branch
8.2 #4382 #439 Meto:
8.3 #1 #2
8.4 #1 #636 Puma:
8.6 #6105 and #5404 #647 Meto: