BARPA:  Bureau of Meteorology Atmospheric Regional Projections for Australia


This is the homepage for information and updates relating to the BARPA (BARPA) regional climate projections data for use by the Australian research community.

Introduction

BARPA provides the Bureau's higher resolution climate simulations and projections over Australia and its surrounding regions.  This involves downscaling the global projections and global reanalysis (ERA5) using ACCESS as a limited-area dynamical coupled atmosphere-land model - Unified Model (UM) and JULES.

BARPA consists of two systems:

  • BARPA-R is a moderate-scale climate downscaling system based on a horizontal grid spacing of 0.154 degrees (around 17 km). The model is nested inside a global climate model simulation or a global reanalysis. The modelling domain covers 86.336 to 209.4725 degrees in longitude and -55.275 to 15.3315 degrees in latitude. When the modelling output are post-processed to Level 1, the data is cropped over 88.0355 to 207.9275 degrees in longitude and -53.5755 to 13.632 degrees in latitude, to remove boundary artefacts. The model is forced by the sub-daily atmospheric circulation and sea surface temperature from the global climate models (or global reanalyses). The forcing can be engineered as lateral boundary forcing and relaxation to the global model's large-scale atmospheric state (i.e., nudging). More details in Su et al. (2022), Bureau Research Report 069.
  • BARPA-C is a convective-scale climate downscaling system based on a horizontal grid spacing of 0.04 degrees (around 4.4 km). The model is nested inside BARPA-R simulation. The modelling domain covers 107.02 to 160.90 degrees in longitude and -46.69 to -4.01 degrees in longitude. More details in Bureau Research Report 114.

BARPA-R Regional Projections

A set of 7 priority climate models have been selected from the CMIP6 multi-model ensemble for BARPA-R downscaling. These have been selected based on model performance, data availability, and representation the overall spread of climate-model based projections of Australian rainfall and temperatures (Grose et al., (2023)). The models selected are:

  • ACCESS-CM2
  • ACCESS-ESM1-5
  • NorESM2-MM
  • EC-Earth3
  • CESM2
  • CMCC-ESM2
  • MPI-ESM1-2-HR

for SSP3-7.0 (Scenario 3 'regional rivalry' from CMIP6 with 7.0 W/m2 of radiative forcing by 2100), and SSP1-2.6 (Scenario 1 'sustainability' from CMIP6 with 2.6 W/m2 of radiative forcing by 2100). 

Two models:

  • ACCESS-CM2
  • EC-Earth3

are also selected for downscaling for SSP5-8.5 (Scenario 5 'fossil-fueled development' from CMIP6 with 8.5 W/m2 of radiative forcing by 2100). They are chosen to allow intercomparison with CMIP5 experiments.

These may be expanded in the future.

The ERA5 evaluation run is produced for 1979-2022. 

BARPA-C Convective-Scale Projections

Modelling at finer spatial scales requires significant research and model development. The 2021-2024/25 phase of ACS funding supports creation of BARPA-C projections with a more limited scope than BARPA-R. These projections should be regarded as research runs, as the modelling system continues to improve and mature for future production.

Two climate models are selected for the initial tranche. BARPA-C projections are produced for,

  • ACCESS-ESM1-5, historical (1995-2004, 10 years) and SSP3-7.0 (2051-2060, 10 years) scenarios
  • EC-Earth3, historical (1995-2004) and SSP3-7.0 (2051-2060) scenarios

The GCMs are chosen to reflect the hot warm and wet futures.

The ERA5 evaluation run is produced for 2013-2022 (10 years). 

These may be expanded in the future.

Production

BARPA-R runs for historical, SSP3-7.0, SSP1-2.6, SSP5-8.5 have completed.

BARPA-C runs have completed for historical and SSP3-7.0, with data release expected in 2025. More details on CMIP6-CORDEX datasets - CMIP Community - Opus - NCI Confluence 

Data Access

You can browse the full BARPA holdings in the NCI Data Catalogue.

NCI users: To access the BARPA data from either NCI's Gadi, or via the ARE interface, you must first register with the project py18 containing the BARPA datasets. The registration link will direct you to MyNCI portal where you will be asked to agree to the licensing, terms and conditions.   

Non-NCI users: You may access the BARPA data via the NCI THREDDS Data Server, linked from the NCI Data Catalogue.

Licensing, terms and conditions

BARPA is licensed under Creative Commons Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/).

Conditions of Use: The data collection is considered a research product containing direct modelling outputs from the ACCESS (Australian Community Climate and Earth System Simulator) that has not been fully evaluated. Users are advised to refer to the Extended Documentation for the known issues and undertake evaluation of the data prior to use in their applications. 

The Bureau of Meteorology seeks user feedback on the quality and usage of the data, to help identify areas for improvements. 

The Bureau can also advise appropriate use of the data. 

Please refer feedback and questions on data use to help@nci.org.au.

Disclaimer: http://www.bom.gov.au/other/disclaimer.shtml 

Published Evaluation and Assessment

Please contact help@nci.org.au to add your relevant publications to this list.

Su, C.-H., Stassen, C., Howard, E., Ye, H., Bell, S. S., Pepler, A., Dowdy, A. J., Tucker, S. O., Franklin, C. (2022), BARPA: New development of ACCESS-based regional climate modelling for Australian Climate Service, Bureau Research Report 069, accessed online http://www.bom.gov.au/research/publications/researchreports/BRR-069.pdf

Stassen, C., Su, C.-H., Dowdy, A., Franklin, C., Howard, E., Steinle, P. (2023), Development and assessment of regional atmospheric nudging in ACCESS, Bureau Research Report 086, accessed online: http://www.bom.gov.au/research/publications/researchreports/BRR-086.pdf

Howard, E., Su, C.-H., Stassen, C., Naha, R., Ye, H., Pepler, A., Bell, S. S., Dowdy, A. J., Tucker, S. O., and Franklin, C.: Performance and process-based evaluation of the BARPA-R Australasian regional climate model version 1, Geosci. Model Dev., 17, 731–757, https://doi.org/10.5194/gmd-17-731-2024, 2024.

Howard E., Su, C.H., Stassen, C., Ye, H., Lipson, M., Narsey, S., Franklin, C. (2025) BARPA-C: Trialling of Convection Permitting Regional Climate Modelling for the Australian Climate Service. Bureau Research Reports, 114. ISBN: 978-1-925738-57-5, accessed online: BARPA-C: Trialling of Convection Permitting Regional Climate Modelling for the Australian Climate Service

Acknowledgements

The production of BARPA was supported with funding from the Australian Climate Service.

The availability of BARPA data at NCI has been made possible through the Australian Climate Service, and support of NCI.


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