Data Updates
Users should be aware that SILO data are constantly evolving:
Recent datasets grow rapidly as new observational data are added (while some stations report in real-time, it may be several months until data are received from all stations);
Older datasets may grow slowly as hand written (paper-based) records are digitised; and
All datasets may undergo minor changes as a result of error detection programs undertaken by SILO and the Bureau of Meteorology.
Clients requiring a static dataset for analysis should download and archive their own copy of the data.
Updates
Significant updates to SILO are listed below:
15 June 2022
All products were updated to incorporate revised data from the Bureau of Meteorology, similar to previous updates. Users may notice:
· some large changes: large differences typically arise when an erroneous value has been removed from the dataset used to construct an interpolated raster.
Data were updated over the entire period supported by SILO (1 Jan 1889 to present).
24 September 2020
The daily and monthly rainfall gridded surfaces were recomputed with improved scaling. The NetCDF files use scale and offset parameters to compress the data. The new values enable a wider range of rainfall values to be stored. This change only affects the NetCDF file format; the data used to compute the surfaces were not changed.
8 July 2020
All products were updated to incorporate revised data from the Bureau of Meteorology. The new datasets are similar to the previous datasets, however users may notice:
· some large changes: large differences typically arise when an erroneous value has been removed from the dataset used to construct an interpolated raster.
· many minor changes: small changes are expected because the long term means have been updated and the resolution has been improved in some variables (for example, the resolution of interpolated temperatures has changed from 0.5ᵒC to 0.1ᵒC).
Data were updated over the entire period supported by SILO (1 Jan 1889 to present).
25 September 2019
Interpolated rainfall datasets for the period 1 January 2017 to 24 September 2019 were replaced with new datasets. The original datasets were inaccurate due to an error in the software which generates SILO’s interpolated rainfall datasets.
April 2018
Parameters used for normalising monthly rainfall prior to interpolation were recomputed. For further information about the normalisation procedure, please refer to the SILO reference paper.
Modifications
Modifications to the observed data, station coordinates or algorithms affecting derived data are listed below:
November 2023:
Decline in the number of observing stations means that the previous cloud oktas/sunshine hours methodology is no longer viable and solar radiation estimates are becoming increasingly biased relative to high quality radiometers.
Solar radiation data after 1990 is now BoM sourced satellite radiation data. Missing data has been infilled with the previous interpolated radiation data which is calculated from cloud oktas and sunshine hours. Negative satellite radiation estimates and values less than 1MJ/day set to 1MJ.
New data code introduced to outputs (42) signifying the use of BoM satellite radiation estimate.
This affects all previous radiation data after 1990 and those derived variables (e.g., potential evaporation) that use solar radiation in their calculation.
