Land working group, meeting minutes 2024

Here are the minutes from the Land modelling working group meeting. If we’ve missed anything you feel is important please feel free to add it below or edit this post (it’s a wiki post).

DATE: 20/02/2024
Attendees: 10

CABLE-JULES comparison
There is definitive interest in running some comparison of the 2 land models. The following runs could be used in this comparison:

  • ACCESS-AM3 runs with CABLE and JULES. These will be done as part of the development work for CMIP7. Currently, only the biophysics is coupled in AM3. There will be runs done for the March hackathon, but keep in mind the science in these early runs is flaky in the CABLE version. This should be seen as an exercise to identify where improvement is needed.

  • AB is going to run CABLE over Australia with AGCD and ERA5 at 0.25° with the NESP2pt5 branch. This includes POP. AU says it would be good to include in the comparison as CABLE-POP and standard CABLE have shown significant differences before.

  • CR’s team has run JULES with AGCD and ERA5 for 20 years at 5km. Focus on recent years.

  • RECCAP runs? Would these be useful? Maybe but CR points out run focusing on carbon don’t usually output runoff.

CR would like to have runoff outputs for comparison of hydrology. Could plug these through their river routing model.

AU: will the groundwater be available in these comparison runs.
RK: solved 3 bugs, testing to see if any other bugs left and to see if the fixed bugs have changed the behaviour during spin-up. All fluxnet sites run with debug option on with the bugs fixed. Then, we need to review changes to the code outside the groundwater to ensure agreement these are acceptable bug fixes.
CC: Timeline maybe in a month.

GA: will we leverage ilamb for the comparison? Does ilamb have the datasets we need?
A few Australia-specific high-resolution datasets exist that we may want to add to ilamb. Use the working group to create an agreed list of datasets we can then send to MED team.

CC: NRI land team can run ilamb on the runs outputs and make the results available to the community as we need to get more comfortable with ilamb.

Experiments with Working Group resources
CC: Need better reporting of the resource usage. Need to provide a list of proposed experiments to the SAC by mid-March for Q2 of 2024.

AU: can the experiments for the CABLE/JULES comparison use these resources?
CC: yes. It helps with planning the development of CABLE and JULES. And the scheme is not oversubscribed anyway.

Action: CC to provide a way to propose experiments.

Agenda items
CC: it would be good to have input from everyone for the agenda. What is the best way to collate ideas?
Possible solutions:

  • send email one week before to ask for items. Downside: the email will likely be sent to a lot more people than those interested in the working group.
  • could the Announce post be a wiki and people could populate the agenda directly? Possible but if the Announce topic is open, there is a risk people reply via emails and spam everyone.
  • create a forum topic with a list of potential subjects of discussion. People populate the list when they want. Co-chairs pick items from the list and other urgent items to create the agenda for the meeting. A link to the list and a call out for ideas is sent with all meeting announcements. chosen solution

Strategy paper
CR: meeting in a couple of weeks for interested parties.
RL: could we use the WG meeting in 2 weeks for that purpose?
IH: should we instead keep that meeting to discuss the land-focused evaluation we would want out of the Evaluation Hackathon?
RL: there will be time at the Hackathon itself for these discussions.
Decision: next WG meeting will be dedicated to the preparation of the strategy paper on “challenges and future directions of land surface models for hydrology - Australian community perspective”.

DATE: 19/03/2024
Attendees: 12

Mengyuan Mu’s presentation: How do land surface models behave as vapour pressure deficit increases?


  • ESMValTool could be very useful for science evaluation on the longer term but a very very steep learning curve.
  • need timeseries of grid cell at FLUXNET sites from the coupled run.
  • action items from the Hackathon: Issues · ACCESS-NRI/CMIP7-Hackathon · GitHub
  • Lauren Stevens has code from previous efforts here: umplot in branches/Users/lxs599 – cable
  • worth keeping an eye on UKMO’s porting auto-assess to ESMValTool.
  • pre-processors look potentially useful.

Here are the minutes from the Land modelling working group meeting. If we’ve missed anything you feel is important please feel free to add it below or edit this post (it’s a wiki post).

DATE: 02/04/2024
Attendees: 12

We discussed what global met forcing datasets are being used across the community to provide information to ILMF (mainly GSWP3, WATCH-WFDEI, ERA5, CRU-JRA). New/updated datasets are being developed that start around 1950, we discussed whether these are suited to carbon cycle studies needing spin-up from pre-industrial conditions.

Gab: Information we want to see for model evaluation and how we want this information to be presented. Showing a mock-up of how the analysis could be presented. With several levels of granularity: PLUMBER plots per tested configuration, window inserts for summative plots and for plots per variables (with a drop-down to choose the variable), plots per site (with timeseries, diurnal cycle etc.) and colour-coded information to quickly show at each site if the test branch is better.

Negin: Should we add urban sites?

  • should we add them from the start? Is the data ready? Globally there are sites that are ready to pull from. Mat can give some sites. We will discuss in a future meeting if different metrics need to be applied to urban models.

We are also not representing agriculture for now in benchcab.
Permanent ice is not represented. Lakes neither. We have sites at wetlands and some points that are frozen half of the year.

Anna: summary tables like in ILAMB. Gab, these already exist in Claire asked if these tables can be visually similar to ILAMB’s so it’s faster to interpret when switching between the 2 systems.

Beta testing: The system is a bit too clunky right now for generic use. Once we have something nicer to use, we are happy for people in the community to get involved with testing as they wish.

Ramzi: It might be good to have one overall grading “number” across sites, metrics and configurations.
Gab would like a system that gives the user a statement of what has significantly changed but that would be hard to do.