BAMOS
Sept 2017
based on post-processed data from the ACCESS model, and
so far has been provided to New South Wales, Tasmania and
Western Australia. An Initial Analysis for South Australia is
currently underway. The Initial Analysis is produced for the
smaller sub-domains shown in Figure 1 and typically covers the
period 2011 to 2015. These data were provided as a proof-of-
concept and allows agencies to explore the use of this type of
information for their applications.
validating the necessity to undertake higher resolution
reanalyses. In other words, the 12-km suite BARRA-R provides
better initial conditions for the 1.5-km downscaling suite, than
ERA-Interim.
Evaluating the reanalysis Evaluation of the reanalysis data against gridded products such
as AWAP (raingauge-interpolated) rainfall data (Figure 3) shows
that BARRA-R—unlike AWAP—not only provides a complete
spatial coverage over the continent and the ocean but also
captures the large scale spatial characteristics with typically
comparative magnitudes.
Our evaluation results for the 12-km reanalysis suite include
a comparison against temperature at 2 m height from ERA-
Interim (Figure 2). ERA-Interim is a global atmospheric
reanalysis at approximately 80 km resolution produced by the
European Centre for Medium-Range Weather Forecasts. The 12-
km reanalysis is found to be more skilful than ERA-Interim (blue
curve) in terms of Root Mean Square Error (RMSE) and bias. This
result illustrates the importance of increasing spatial resolution
from 80 km to 12 km to better reflect surface conditions, While we are continuously monitoring the output we are
producing as part of the activities to derive the reanalysis
products, there is also a need to evaluate the reanalysis products
against observations to gain an understanding of how well
these products represent observed meteorological conditions
and where post-processing of data (e.g. bias correction) would
be appropriate. Cannon et al. (2015) for example present an
evaluation of wind speeds from Modern Era Retrospective-
Analysis for Research and Applications (MERRA) produced by
Figure 1. Region of Australian reanalysis product. The larger region shows the domain covered by the 12-km reanalysis
(BARRA-R) system with the smaller boxes showing the area of four 1.5 km downscaled subdomain, namely BARRA-PH,
BARRA-AD, BARRA-TA, and BARRA-SY (left to right). The exact extent for BARRA AD is yet to be finalised.
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