Improved historical solar radiation gridded data for Australia

An improved blended data method was developed for preparation and generation of solar radiation gridded datasets for SILO; Queensland Government database containing point and gridded daily climate data for Australia from 1890 till present designed for crop and pasture modelling. The new blended data method incorporates three sources of solar radiation data: radiometer measurements, sunshine duration, and cloud-cover observations. The new method converts all data sources to the percentage extra-terrestrial radiation using new conversion equations derived from the experimental data and thus the conversion tables previously used are now redundant. Comparison with satellite derived estimates shows that the blended data method has reduced bias compared to the previous method. The blended data method addresses the need for historical pre-satellite solar radiation gridded datasets for climate and agricultural modelling, model calibration, and computation of synthetic evaporation rates.