 Climate Data Quality
How important is climate data quality?
- For some climate analysis, e.g. climate change detection,
additional quality control is required.
- Variations in instrument type over the years have
introduced inconsistencies in climate data records resulting
in non-climatic 'jumps' and artificial trends.
Other changes such as construction of nearby buildings
or growth of vegetation cause similar affects.
- These artificial changes are often of a size
comparable to natural climatic variations,
and so they make the detection of real climatic trends
very difficult.
A change in instrument shelter around the turn of the
century at many Australian sites was associated with
a sudden 'jump' in recorded temperatures.
An example of an inadvertent "change" in climate
is shown below.
When the Lord Howe Island site relocated about
500 metres closer to the coast in the early 1950s,
recorded daytime maximum temperatures suddenly fell
and overnight minimum temperatures increased causing
artificial trends in the historical records.
- Procedures to identify and adjust for these
non-climatic influences generally involve
- analysis of historical station information,
- visual examination of climate records for
potential problems, and
- application of statistical tests to provide
an estimate of artificial biases and confidence in
their detection.
- Steps are in place to ensure that consistent
climate observations are maintained with the
introduction of new instrumentation.
This is particularly important given the increase in
the number of Automatic Weather Stations (AWSs)
in the observation network.
- A Climate Data Quality Issues (CDQI) group has
been established to identify and address issues which
have the potential to cause deleterious impacts on
the homogeneity and continuity of the Australian
climate record.
These aims will be achieved through
- contributing to the maintenance of the Reference Climate
Station (RCS) network;
- monitoring observations, coding practices,
and data archiving policy so that the climate data
archive is suitable for climate monitoring and research;
- conducting studies into climate data quality
including homogeneity issues (which are primarily
caused by the effects of changes in site and
instrumentation)
particularly for the Reference Climate Station
(RCS)
network; and
- recommending comparison experiments between
different instrumentation to provide data for
homogeneity assessment.
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