Minutes of the code management group meeting 2024-03-25

Code management group minutes

Teleconference Details

Monday 25th March 2024, 10.00am - 11.30am GMT

Meeting via Zoom - details have been emailed

Met Office:

Cambridge:

Leeds:

NIWA:

Canterbury:

CSIRO:

Apologies:

Actions from this meeting

Actions from the Last Meeting (NLA)

Minutes of the code management group meeting 2024-01-15

(ongoing) NLA to put C_SPECIES definitions in the Redundant Code table (short-term), and switch to use M_SPECIES instead. Talk with JH about AQUM tests and requirements. Note that there will be problems with exoplanets and >100km top configs where M_air not constant. LA to make a branch and progress. May want to move to redundant code table at some point
(ongoing) GM/DG to update table on UKCA wiki documenting GLOMAP versions. DG/GM to consider the code and lodging process for GLOMAP developments and consider a suitable rose-stem test supported by NLA.
(ongoing) JH on update API document to UMvn13.4 release. NLA to provide feedback before it is be circulated.
(ongoing) ALL look at um:#6203 showing other unprotected rose-stem options and think about any code/settings they are interested in.
(ongoing) NLA, AJH to identify owner for TropChem item in the Desirable changes not Tested Table. AJH to arrange call with NLA to discuss this and creation of rose-stem jobs. Should also update the UKCA UMDP to reflect which configurations are supported/widely used.
(ongoing) DG and AJH to chat offline regarding bug #152 (correct bug in water_content_v)
(new) ALL to consider ordering of the Progress with Priorities table and highlight things that should be higher priority, and any other tasks that need to be included
(new)DG to take ownership of Priority #2
(new) NLA to remove the copy of the priorities table from future agendas, so we will instead use the linked table above
(new) NLA to send round a Doodle poll for mid-late March

Standing actions

(ongoing - standing item) CMG to monitor list of bugs and circulate between group for owners.
(ongoing - standing item) At CMG future meetings there should be included an appendix listing the open bugs. If a ticket is included it is not an open bug (as the owner of ticket is person doing lodging).
(ongoing - standing item) ALL with access to keep monitoring ukca_bugs email list.
(ongoing - standing item) ALL to think about if code changes will change KGO and let systems team know in good time, and remember to include the UKCA keywords to all UKCA tickets. This should be a standard part of our working practice. Note also the required keywords.
(ongoing - standing item) ALL to note, review, and remove obsolete/redundant code
(ongoing - standing item) ALL closed ticket owners to produce a summary of their change for the UKCA newsletter for special occasions, e.g. to coincide with Composition-Climate Meeting.
(ongoing - standing item) Code Owner to produce draft newsletter for CMG to approve.
(ongoing - standing item) ALL to consider other rose-stem tests that could be included.
(ongoing - standing item) ALL to email NLA with suggestions for next set of tutorials.

Tickets (NLA)

Tickets on MOSRS:

PLEASE REMEMBER TO USE THE UKCA KEYWORD FOR ALL UKCA CHANGES

NOTE: The UM requirement for LFric testing of all changes under UM:src/atmosphere, UKCA:src/science, and UKCA:src/control/core

Please also give any feedback on the UM release cycle to NLA to pass-back to UM Sys.

Message from UM Sys - please take care when considering keywords. It is important to get these correct for the Code Review process.

Progress with Priorities (NLA)

ACTION REQUEST FROM UKCA SCIENCE & MANAGEMENT BOARD: CMG to provide list of priorities & their status, with particular thought to UKESM2 changes that will be required.

Progress with Priorities table

Bugs/Bugfixes (NLA)

Open Bugs

#	Description	Ticket	Owner	Comments
124	H2 and N2 cannot be set for RCP and WMOA1 scenario routines	UM:#5620	Mohit Dalvi	Values are hard-wired in the code and cannot be changed without a branch Will be handled at UM11.8 At least for the next version Keep open Tested it quickly - N2 is used from namelist but not obvious, but H2 needs further testing
128	Bug in UKCA stratospheric chemistry diagnostics	UM:#5839	Luke Abraham	pre-UMvn10.0. The indexing/values of diagnostics m01s50i101-i104 are incorrect. Fixes provided for vn11.1 and vn11.7. May affect CMIP6 diagnostics May be best to lump #101. NLA to contact JM Should be fixed for UKESM2 Biggish ticket for 12.2 with bug fixes. See if can be done for 12.3 Nice to do ASAP, but if just diagnostics might be able to do at a later time.
143	Error in print statements from UKCA_TRACERS_COPY_FROM_UM			The final species listed in the diagnostic print statement seems to have very large concentrations (O(1E+08)) compared to others in the ppm-ppt range. Does not seem to affect model output. Reported by James Weber.
144	interchangeable use of specific humidity and water vapour mixing ratio	#6813		UKCA includes calculations of relative humidity, clear-sky relative humidity and saturation vapour pressure. Relative humidity calculations should be based on water vapour mass mixing ratio but are in part based on specific humidity. Also, the calculation of saturation vapour pressure is derived from saturation mixing ratio but uses a formula for deriving SVP from saturation specific humidity. This interchangeable use of specific humidity (ratio for moist air) and mixing ratio (ratio for dry air) in existing configurations introduces small numerical errors in UM and LFRic model runs. These bugs were identified at UM version vn12.2 and have been highlighted by comments in code lodged with UM ticket #6660 (in ukca_main1-ukca_main1.F90 and atmos_ukca_humidity_mod.F90). All UKCA configurations are affected. JH doesn’t think it’s complicated but not particularly trivial either.
145	all_ntp not explicitly dimensioned in UKCA_MAIN	Possible fix here		all_ntp not being dimensioned explicitly in ukca_main1-ukca_main1.F90. Highlighted in NCAS CMS ticket https://cms-helpdesk.ncas.ac.uk/t/nested-ukca-suite-on-archer2/604 raised by Paul Field. Grenville Lister has found the cause and implemented a possible fix https://code.metoffice.gov.uk/trac/um/changeset/110132/main/branches/dev/grenvillelister/vn12.0_all_ntp_fix
150	ukca_ddepctl bug for 27 tiles	ukca:#19		Will alter results of 27 tile ukesm1 runs. Fixed in Jules code by Garry, so no bug in UKESM2. Will affect any job where ice isn’t the last tile. Not that not all UKCA configurations use JULES - e.g. ACCESS May not fix in UKCA - will only fix in JULES repo. If it’s a small enough change, JM may sign off the fix. Will still be a while until CSIRO will use the latest UM versions. \|\| May not need a temporary logical.
152	correct bug in water_content_v	ukca:#130	Dan Grosvenor and Alan J Hewitt	The code appears to be different to the description in the text book Fundamentals of Atmospheric Modelling DG and AJH to chat offline regarding bug #152 (correct bug in water_content_v)

Redundant Code (NLA)

Code for deletion

PLEASE REMEMBER TO EDIT THE ORIGINAL REDUNDANT CODE TABLE AND NOT THIS PAGE

The NG-Composition Project Board has agreed to use the Redundant code table as the Technical Debt Log for UKCA as part of that project. This has highlighted the issue that some areas of code are not listed as being redundant, but are also not tested/used routinely and are not in any rose-stem tests, for example 2D photolysis and the TropIsop and Strat chemistry schemes. We have been asked to review this code and list untested code which is still desirable to be included for testing, and to ensure that other areas of code are listed for deletion.
It is noted that we may have more time to work on these once LFRic work is done, and most can't be retired as under rose-stem for GA7.

#	Description	Ticket	Remarks	Status	Timeframe	Owner	Comments from previous meetings
4	ukca_strat_update.F90 - relax_ozone	UM:#1505	None	PROPOSED	Medium-term	Luke Abraham
5	Backward Euler Standard Tropospheric Chemistry	UM:#1507	None	PROPOSED	Medium-term	Fiona O'Connor
6	Wet oxidation of SO2 in GLOMAP	UM:#4475	None	PROPOSED	Medium-term	Colin Johnson	JM to look at this re: UKESM1 c.f. offline GLOMAP. JM to take ownership. Still needed for CTM. Relevance for standalone code and later coupling to CTM.
7	Updraft velocity - l_conv_tke	UM:#3668	Proposed in December 2017. Approval being sought for GA series (likely GA8).	PROPOSED	Medium-term	Alan J Hewitt / Ian Boutle
8	All backward Euler chemistry schemes	None	Note that this is only for the “hard-coded” BE schemes. Quite a lot of work would be involved, but good as a longer-term aim. Note that problems for AQUM would need to be addressed first.	PROPOSED	Long-term	Luke Abraham
9	Deprecated UKCA netcdf attribute options	UM:#2513	'emission_type', string type attributes no longer recommeneded. Need some time for most new code to adopt these. Still used in AQUM files.	DEPRECATED	Medium-term	Nick Savage	AQUM are addressing the files. Have gone from operational jobs, have ticket to remove from rose-stem. LN to document. These have been removed from AQUM. AQUM work has been done. From AS: In the ancil ticket linked from #2513 (https://code.metoffice.gov.uk/trac/ancil/ticket/782) it says that GA7 depends on the old format files, and as far as I know this is still true. In the 3-step timeline suggested, we haven't reached step 2 unfortunately. That ticket was about ensuring GA8 did not use the old attributes. I believe that GA8 is due for release in the next few months (it has been a very long time coming), so UM vn11.5 may be the last version at which GA7 is supported. Do you mind waiting a bit longer? AJH to follow-up with LA
10	ASAD families chemistry	None	Families chemistry has not been used for many years (since at least UM6.1. It is likely that it no longer works if turned on, and it complicates the code making other developments harder	DEPRECATED	Short-term	Luke Abraham
11	Dry deposition 9 PFT option	None	The 13 PFT option has been adopted for UKESM1. The 9 PFT option is possibly not being used at all. Proposed in June 2018.	PROPOSED	Long-term	Alan J Hewitt	AJH may be able to remove 9 PFT option, but it might be better to do when removing other dry-dep temporary logicals.
12	Remove explicit `C_SPECIES` constants and calculate these from `M_SPECIES` and the mass of air	None	Will have wide-ranging rose-stem KGO breakages	PROPOSED	Short-term	Luke Abraham
13	Remove temporary logical l_fix_nacl_density Introduced at UM:#2405	UM:#3490	Requires AMIP testing and a GMED ticket Could be accepted to GA9	PROPOSED	Medium-term	Jane Mulcahy	See JM GMED action
15	Remove temporary logical l_fix_ukca_impscav Introduced at UM:#1421	UM:#4145	Approval being sought for GA series (likely GA9) GMED:#402	PROPOSED	Medium-term	Alan J Hewitt	See JM GMED action
16	Remove temporary logical l_fix_improve_drydep Introduced at UM:#1250	UM:#3997	Approval being sought for GA series (likely GA9) GMED:#393	PROPOSED	Medium-term	Alan J Hewitt	See JM GMED action
17	Remove temporary logical l_fix_ukca_h2dd_x Introduced at UM:#4157	UM:#4245	Approval being sought for GA series (likely GA9) GMED:#410	PROPOSED	Medium-term	Alan J Hewitt	See JM GMED action
18	Remove temporary logical l_fix_neg_pvol_wat Introduced at UM:#4383	UM:#4416	Approval being sought for GA series (likely GA9) GMED:#421	PROPOSED	Medium-term	Alan J Hewitt
21	Remove code behind L_use_stratclim from ukca_fastjx_mod Introduced prior to MOSRS	UM:#4854	This could either be properly included via a namelist or removed from the UM	PROPOSED	Medium-term	Alan J Hewitt	LA contact OW about progressing FastJX-RADAER work Ties in with API work. MD/NC to take a look, can be removed. Do as part of API. Relevant person take ownership as part of API work NC to take ownership as part of his work
24	Remove ability to use of Cambridge 2D model data from ukca_stratf.F90			PROPOSED		Neal Carr	Need to confirm from wider community for possible tropospheric configs and other choices for top-bdy
25	Change from using ukca_chem_master.F90 to a file-read for the chemical mechanism			PROPOSED	Short-term	Luke Abraham	Current chem_master module has compiler issues with that require changes to optimisation level on some compilers. A file read would be more flexible and would allow the mechanism to be more easily changed not requiring UM/UKCA code tickets.
26	highorder_scheme			PROPOSED		Mohit Dalvi	May need to test this in rose-stem
27	Stratospheric photolysis: Remove code for reading of JTABLE rates (calcjs_mod) and prescribed O3 ,temperature (initjtab_mod). The read methods do not seem to have ever been used in the UM as required values are required hardwired in respective modules. Necessary for Photolysis API and LFric porting			PROPOSED	Short term	Mohit Dalvi

Desirable Science not tested

PLEASE REMEMBER TO EDIT THE ORIGINAL SCIENCE NOT TESTED TABLE AND NOT THIS PAGE

See also the complete list of unprotected rose-stem options

#	Description	Remarks	Owner
1	Use of tropospheric (2D) look-up table photolysis	Still useful to compare against FastJX. May be used for a "fast" configuration. Will be doen as part of photolysis refactoring
2	TropIsop chemistry configuration	May be useful in a "fast" configuration & to drive GLOMAP-mode. Useful for low-top configurations.
3	Strat chemistry configuration	Useful for stratospheric studies, particularly with a high model top.	Luke Abraham

Round (virtual) Table of current activities, plans

Person	Activity