Land working group, meeting notes 2025

Land Surface Working Group
, ,
8

Meeting Minutes

Date: June 17, 2025
Attendees: 12

1. Workshop Planning Overview

Presented by: Lachlan Whyborn, Mathew Lipson

  • Workshop Schedule:

    • Monday: Start around midday. Includes:
      • Review of current status and work plan (short and long term).
      • Six science talks based on submitted abstracts.
      • Training session on land ancillaries and data generation.
    • Friday: Full-day session.
      • Revisit and revise the work plan based on workshop learnings.
      • Three 30-minute discussion sessions to determine focus areas for the next 6 months to 2 years. Discussion topics to be selected by the working group in advance.
      • Afternoon “working bee” sessions to make progress on discussed topics.
        • Feedback: it would be good to continue on last year’s work.

  • Additional Notes:

    • Consideration of attendance overlap between Monday and Friday.
    • ACCESS training scheduled for Tuesday to avoid conflicts.

2. Presentation 1: Australian PFTs in ACCESS and CABLE

Presenter: Alex Norton

  • Motivation: Improve representation of Australian vegetation in ACCESS and CABLE models by introducing more ecologically relevant PFTs.

  • New PFTs Introduced:

    • Australian Mesic Broadleaf Trees
    • Australian Xeric Broadleaf Trees

  • Methodology:

    • Use NVIS data to map current vegetation.
    • Apply LUH3 data to simulate land use change back to 1850.
    • Assign new parameters to the new PFTs using trait data from collaborators.

  • Findings:

    • Improved spatial representation of Australian vegetation.
    • Notable reduction in shrubland and bare ground areas.
    • Some discrepancies between LUH3-derived and NVIS pre-1750 maps, especially in mesic tree coverage.

  • Discussion Points:

    • Consideration of lakes and ephemeral water bodies. There is no inland lakes in the current ACCESS-ESM1.6 PFT distribution in Australia or this new distribution.
    • Limitations of LUH3 data accuracy in Australia.
    • Potential for future improvements and parameterization.

3. Presentation 2: PFT Representation in JULES

Presenter: Siyuan Tian

  • Objective: Assess impact of improved PFT fractions and LAI on JULES simulations.

  • Data Sources:

    • MODIS-derived FPC data.
    • NVIS for tree/shrub partitioning.
    • Geoscience Australia for urban and bare soil classification.

  • Experiments:

    • Compared IGBP, CCI, BOM climatology, and annually varying PFT fractions.
    • Evaluated against flux tower data, satellite ET, GRACE TWS, runoff gauges, and MODIS LST.

  • Key Results:

    • Improved latent and sensible heat fluxes with BOM-derived PFTs.
    • Better land surface temperature simulations.
    • Slight improvements in GPP and runoff, especially in arid regions.
    • Need for further evaluation using independent GPP datasets and OzFlux sites.

  • Discussion Points:

    • Importance of dynamic vegetation inputs for weather and hydrology applications considering the timescales for the variations used.
    • Considering the largest impact is on surface temperature, analysis of a coupled simulation would be interesting to do.
    • Urban area treatment in JULES and potential for refinement.
    • Future work to identify model weaknesses in hydrological processes.

Next Meeting

Date: July 1, 2025
Note: Good luck to all attending the AMOS conference next week!