Land working group, meeting notes 2025

Meeting Minutes

Attendees: Ian, Rachel, Lachlan, Mat

WG Project updates

Lachlan presented some initial outputs of the CABLE ancil workflow LCT (using CCI) compared with AM3 (using NCAR 0.5°) for n96.

Initial crosswalking decisions follow JULES logic. Some issues outstanding:

  • CCI missing barren area in North America, to check

  • C3 crops are set to 100% in any grid containing any fraction, following JULES logic of ice (corresponding tile number). Lachlan has applied fix.

  • Tundra locations incorrect. Lachlan aware, similar issue to above, Lachlan will fix.

  • In JULES if it is an ice point, must be 100% ice in JULES, but not CABLE, because of different way soil column is represented. Opportunity to explore in future.

  • Remember that any changes to landcover will affect soil (e.g. ice). However the JULES workflow ensures all ancils are created based on the landcover (it is a dependency in the suite, other tasks branch from it).

  • Have to be careful about bare soil. JULES will need more bare soil than CABLE because of the different way it deals with the canopy.

  • Issues of LSM, the current CCI shows odd large lakes, e.g. Lake Victoria
    This comes from the JULES workflow of CCI, which includes a pre-processing step. The pre-processing code here e.g. states:

Set Aral sea and lake Victoria as ocean (rather than in-land water). The motivation to be more closely aligned to the ocean landsea mask.

We will conform to ACCESS-CM land sea mask when available. Otherwise will need to decide whether to generate a new CCI source for the relocatable regional workflow that deals with lakes differently.

Meeting with another WG

Probably first like to meet either ESM or Atmosphere. Should decide on theme for each WG to focus on.

For ESM

In terms of theme could be:

  • CM3 vs AM3 comparison
  • Carbon cycle

However, they are still running ESM with JULES. Better to wait for production runs, idealised ESM1.6. Potentially 6 months?

Atmosphere

Not discussed (to consider next meeting discussion)

UM version

Currently:
AM: 13.1
CM: 13.0
rAM: 13.5

Decision on version numbers to be made by Andy H., Martin Dix, Claire Courage, Christian Jakob, Julie Arblaster, Matt Woodhouse etc.