This is the homepage for information and updates relating to the BARRA version 2 (BARRA2) atmospheric reanalysis data for use by the Australian research community.

• FAQs
• Known Issues
• BARRA2 Parameter Descriptions
• Fact sheet

Introduction

BARRA2 is the new version of the regional atmospheric reanalysis over Australia and surrounding regions, spanning 1979-present day time period. When completed, it replaces the first version of BARRA (Su et al., 2019), completed in June 2019, which provided a shorter 1990-2019 February reanalysis.

A reanalysis differs from a climate simulation such as CMIP6, CORDEX or BARPA. It uses data assimilation techniques to produce an observation-constrained model estimate of the past atmospheric states. They draw short-term model states towards observations from multiple, disparate sources. A physically realistic model provides the means to infer atmospheric states at locations without observations from the limited collection of irregularly distributed observations. 

BARRA2 consists of two systems:

• BARRA-R2/RE2 is a moderate-scale reanalysis system, where BARRA-R2 is the deterministic reanalysis on a horizontal grid spacing of 0.11 degrees (around 12 km) and BARRA-RE2 is the ensemble on a horizontal grid spacing of 0.22 degrees (around 24 km). The modelling domain covers 87.27 to 208.6 degrees in longitude and -59.18 to 14.19 degrees in latitude. When the modelling output are post-processed to Level 1, the data is cropped over 88.48 to 207.39 degrees in longitude and -57.97 to 12.98 degrees in latitude, to remove boundary artefacts. More details in Su et al., (2022) Bureau Research Report 067.
• BARRA-C2 is a convective-scale downscaling system based on a horizontal grid spacing of 0.04 degrees (around 4.4 km). The modelling domain covers 107.02 to 160.90 degrees in longitude and -46.69 to -4.01 degrees in longitude. More details in Su et al., (2024) Bureau Research Report 097.

Production

BARRA-R2/RE2 and BARRA-C2 historical runs for 1979-2024 have completed. Some re-runs may be required to resolve issues. It is being updated to present, 3-4 months behind present day.

Data Access

You can browse the full BARRA2 holdings in the NCI Data Catalogue.

NCI users: To access the BARRA2 data from either NCI's Gadi, or via the ARE interface, you must first register with the project ob53 containing the BARRA2 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 BARRA2 data via the NCI THREDDS Data Server, linked from the NCI Data Catalogue.

Licensing, terms and conditions

BARRA2 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.

From the development team:

• Su, C.-H., Rennie, S., Torrance, J., Howard, E., Stassen, C., Lipson, M., Warren, R., Pepler, A., Dharssi, I., Franklin, C. (2024), BARRA-C2: Development of the kilometre-scale downscaled atmospheric reanalysis over Australia, Bureau Research Report 097, accessed online http://www.bom.gov.au/research/publications/researchreports/BRR-097.pdf
• Su, C.-H., Torrance, J., Rennie, S., Dharssi, I., Tian, S., Howard, E., Pepler, A., Stassen, C., Steinle, P. (2023), Preliminary assessment of regional moderate-resolution atmospheric reanalysis for Australia, Bureau Research Report 084, accessed online http://www.bom.gov.au/research/publications/researchreports/BRR-084.pdf
• Su, C.-H., Rennie, S., Dharssi, I., Torrance, J., Smith, A., Le, T., Steinle, P., Stassen, C., Warren, R. A., Wang, C., and Le Marshall, J. (2022), BARRA2: Development of the next-generation Australian regional atmospheric reanalysis, Bureau Research Report 067, accessed online http://www.bom.gov.au/research/publications/researchreports/BRR-067.pdf

Others:

• Palmer, G., Dargaville, R., Su, C.-H., Wang, C., Hoadley, A., Honnery, D. (2025) Validation of BARRA2 and comparison with MERRA-2 and ERA5 using historical wind power generation. Journal of Southern Hemisphere Earth Systems Science 75, ES24028, https://doi.org/10.1071/ES24028

Acknowledgements

The production of BARRA2 was supported with funding from the Australian Climate Service.

The availability of BARRA2 data at NCI has been made possible through the Australian Climate Service, and support of NCI.