About the atmospheric reanalysis
The Bureau's atmospheric high-resolution regional reanalysis for Australia (BARRA):
- helps us understand the weather over Australia
- supports better planning and management, to reduce risks to communities and businesses.
Taking all available observations of past weather, we use a complex weather model to fill in fine detail.
BARRA offers higher resolution in space and time than existing global reanalyses. It's designed specifically for Australia.
Data and parameters
This research involves really big data:
- hourly grids every day
- a 12 km grid covering the Australian continent and the surrounding region
- Australian domains at kilometre-scale resolution
- 70 levels up into the atmosphere (the top is at 80 km)
- nearly 100 meteorological parameters archived hourly and some at sub-hourly time intervals.
These parameters include information about surface conditions such as:
- temperature
- precipitation
- wind speed and direction
- humidity
- evaporation
- soil moisture
- solar radiation and cloud cover information.
Using the ACCESS model
We're using the Australian Community Climate Earth-System Simulator (ACCESS) for this work.
We collaborate with the United Kingdom Meteorological Office to develop the ACCESS set of models. This is part of the Momentum Partnership.
Generations of BARRA
There are now 2 generations of BARRA:
Video: Watch a cloud simulation using BARRA
How reanalysis datasets are used
Fighting fires
Fire agencies are using our reanalysis dataset to better understand bushfires in Australia.
The high spatial and temporal resolution for selected sub-regions:
- allows much more detailed understanding of historic major fire events
- improves understanding of vulnerability and the threat of loss in large events
- can be used to build resilience to future impacts.
Understanding severe weather events
Reanalysis data is used in studies of impactful weather events over Australia. For example:
- tropical cyclones
- east coast lows
- heatwaves.
It provides detailed information on wind, rainfall, temperature and pressure.
Reanalysis data provides a consistent record over time. This can be used to better understand weather behaviour. It helps us develop more accurate forecasts for these events.
Delivering energy
Reanalysis datasets can offer information such as:
- best locations for renewable energy generation
- detailed examination of past extreme weather events over Australia that have affected the energy market.
Supporting agriculture
Reanalysis datasets have fine spatial and temporal scale. They enable detailed study of weather events that impact the agricultural industry. For example, frost, flood and hail.
This can lead to a greater understanding of and preparedness for extreme weather.
Australia's first atmospheric reanalysis – BARRA1
The first version of BARRA covered:
- all of Australia at 12 km resolution
- smaller sub-domains in the mid-latitudes, at higher resolution.
It uses ERA Interim – a global atmospheric reanalysis from 1979, updated in real time – to provide information at the region boundaries.
See available BARRA data for the BARRA1 reanalysis.
Improved reanalysis and projections – BARRA2 and BARPA
Reanalysis and projections of climate hazards
Past climate data are the main source of information on past and present hazards. We use climate projections to assess future hazards.
Funding
The Australian Climate Service is funding:
- the improved regional reanalysis (BARRA2)
- the Bureau's atmospheric regional projections for Australia (BARPA). These use the same models as BARRA2.
Reanalysis data is a crucial reference for improving and understanding climate projections.
Improvements
BARRA2 improves on our first version in several ways. It:
- uses offline land-surface model runs
- assimilates satellite soil moisture observations
- uses an updated global atmospheric reanalysis for boundary conditions – ERA5
- expands the coverage of kilometre-scale information to Australia-wide
- includes an ensemble system for the national (12 km-scale) reanalysis. This produces multiple reanalyses of conditions. It helps us understand the range of possibilities, given uncertainties in the data.
This will improve:
- the land surface conditions in BARRA2
- estimates of near-surface temperature extremes
- ability to use the reanalysis for risk-based assessments
- forcing at the domain boundaries, since ERA5 offers a better spatial and temporal resolution
- ability to use the reanalysis for understanding key hazards driven by local or convective processes.
We'll update BARRA2 over time to give up-to-date information about recent hazards.
Research partners
For BARRA1, we worked on the reanalysis with:
- emergency service agencies
- research institutions including the Antarctic Cooperative Research Centre and University of Tasmania.
The Tasmanian and Australian Governments provided funding for this work. This included through the Tasmanian Bushfire Mitigation Grants Program.
For BARRA2, we continue to work with these agencies to analyse weather during and leading up to historical extreme events.
We also work closely with:
Available BARRA data
BARRA1 data
BARRA1 datasets from 1 January 1990 to 28 February 2019 are available for the Australian domain and sub-domains:
- BARRA-R – 12 km resolution over Australia, New Zealand and the maritime continent
- BARRA-AD – 1.5 km resolution over South Australia
- BARRA-PH – 1.5 km resolution over southwest Western Australia
- BARRA-SY – 1.5 km resolution over eastern New South Wales
- BARRA-TA – 1.5 km resolution over Tasmania.
BARRA2 data
BARRA2 datasets from 1 January 1979 to present day are available for the Australian domains:
- BARRA-R2 – 12 km resolution over Australia, New Zealand and the maritime continent
- BARRA-RE2 – 24 km resolution ensemble over Australia, New Zealand and the maritime continent
- BARRA-C2 – 4.4 km resolution over Australia.
BARRA2 data will be available through NCI after production and post-processing. Like BARRA1 data, it will be provided under a Creative Commons licence.