Minutes of the code management group meeting 2024-09-10

Code management group minutes

Teleconference Details

Tuesday 10th September 2024, 10.00am - 11.00am BST

Meeting via Zoom - see link in calendar invitation

Met Office: AJ MD MS PMJ CN JH AJH DG

Cambridge: NLA

Leeds:

Canterbury: CH

CSIRO:

Apologies: Many could not make at short notice.

Note that there are no longer any NIWA developers working on UKCA.

Actions from this meeting

(new) NLA to send round a Doodle Poll for early- to mid-November. We will fix the date for future UKCA CMG as well
(new) PMJ to look into a test to preserve functionality of NAME with UKCA. Functionality should still work after #170
(new) All to use correct keywords and milestones in tickets for UKCA , UM , LFRIC_APPS

Actions from the Last Meeting

(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. NLA 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 UM13.6 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) 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.
(ongoing) NLA to contact Jonny at NIWA regarding a Cylc 8 Box model configuration.
(ongoing) NLA to add PSCs and thread safe work to Priorities table.
(ongoing) MD to look at where to add photolysis API to Priorities table.
(ongoing) NLA to update working practices to highlight the need to check pressure-level versions of new diagnostics added.
(ongoing) NLA to tidy up redundant code table to take out people no longer working on UKCA.

Tickets

Tickets on MOSRS:

UKCA_repo

lfric_apps_repo

um_repo

PLEASE REMEMBER TO USE THE UKCA KEYWORD FOR ALL UKCA CHANGES (ESPECIALLY IMPORTANT FOR OTHER REPO TICKETS)

PLEASE REMEMBER TO USE THE LINKED:UM or LINKED:APPS KEYWORDS IN YOUR UKCA TICKET FOR LINKED CHANGES

PLEASE REMEMBER TO USE THE LINKED:UKCA KEYWORD IN YOUR LINKED UM and/or APPS TICKETS

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.

It was noted that the LFRic repository split will be happening soon into a core one and a science one. This should then be easier to develop for LFRic as usually only the science code will be changed.

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	Comments from this meeting
124	H2 and N2 cannot be set for RCP and WMOA1 scenario routines	UM:#5620	Mohit	Values are hard-wired in the code and cannot be changed without a branch
128	Bug in UKCA stratospheric chemistry diagnostics	UM:#5839	Luke	The indexing/values of diagnostics m01s50i101-i104 are incorrect. Fixes provided for vn11.1 and vn11.7. May affect CMIP6 diagnostics
143	Error in print statements from UKCA_TRACERS_COPY_FROM_UM	Not yet	???	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.
145	all_ntp not explicitly dimensioned in UKCA_MAIN	???	Not yet 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.
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)	Closed as fixed

Redundant Code (NLA)

Code for deletion

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

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