Mean daily vapour pressure for the Australian continent between 1970-2014. Daily vapour pressure regulates evaporation rates and water need and use. Modelled by expressing each daily value as a difference anomaly with respect to the gridded 1976-2005 monthly mean daily vapour pressures as provided by eMAST_ANUClimate_mmn_vp_v1m0_1976_2005. The daily anomalies were interpolated by trivariate thin plate smoothing spline functions of longitude, latitude and vertically exaggerated elevation using ANUSPLIN Version 4.5. There was an average of 382 Bureau of Meteorology data points available for each day between 1970 and 2014. Automated quality assessment rejected on average 4 data values per day with extreme studentised residuals. Cross validation residuals for all accepted data points had a mean absolute value of 0.51 HPa and a root mean square value of 1.02 HPa. These corresponded to relative errors of around 7% and 11% respectively. A comprehensive assessment of the analysis and the factors contributing to the quality of the final interpolated daily vapour pressure grids is in preparation.

Monthly mean total precipitation for the Australian continent between 1976-2005. Modelled by fitting a trivariate thin plate smoothing spline function of longitude, latitude and vertically exaggerated elevation to the square roots of observed and estimated monthly 1976-2005 rainfall means at 11,697 Bureau of Meteorology stations. Missing monthly precipitation values were estimated by regression with the long term station that provided estimates of the 1976-2005 monthly means with with the least standard error. This was applied to each station with at least 10 years of record between 1931 and 2012. Automated quality controls were applied to the regression process to remove poor quality data. Thus, an average of 66 values per month were removed, giving an average of 11631 data points for each month. These were commonly associated with stations with an old or short period of record, or with an imprecise location. Station elevations were 0.05 degree local averages of grid values from the GEODATA 9 second DEM version 3 as provided by eMAST_ANUClimate_fx_el05_v1m0. The mean absolute error of individual cross validation residuals provided by the spline analysis at 3518 stations with near complete records, of at least 28 years, is 3.9 mm (6.6% of the mean). A comprehensive assessment of the analysis and the factors contributing to the quality of the final interpolated monthly mean precipitation grids is in preparation.

Annual radiation of warmest month for the Australian continent. Modelled by using ANUSPLIN Version 4.5 to fit trivariate thin plate smoothing spline functions of longitude, latitude and vertically exaggerated elevation. Station elevations were 0.05 degree local averages of grid values from the GEODATA 9 second DEM version 3 as provided by eMAST_ANUClimate_fx_el05_v1m0.

Proportion of days in each month with precipitation above 0.2 mm for the Australian continent between 1970-2014. The proportion of wet days per month is useful for estimating evaporation rates and water need and use, and also for estimating solar radiation. Modelled by using ANUSPLIN Version 4.5 to fit trivariate thin plate smoothing spline functions of longitude, latitude and vertically exaggerated elevation. Station elevations were 0.05 degree local averages of grid values from the GEODATA 9 second DEM version 3 as provided by ANUClimate_v1-0_digital-elevation-model-05deg-average_terrain_0-01deg. Anomaly based interpolation was not used because it gave no improvement over direct interpolation, due to the extensive daily precipitation network and the strong spatial coherence of daily rainfall occurrence. Monthly data values were obtained from Bureau of Meteorology daily rainfall data at stations where there were at least 25 days of record and no accumulated days of record, giving an average of 6320 data points per month between 1970 and 2014. Automated quality assessment rejected on average 35 data values per month (0.006%) with extreme studentised residuals. The root mean square of all individual cross validation residuals provided by the spline analysis is 0.060, corresponding to a root men square error in estimating the number of wet days of around 1.8 days per month. A comprehensive assessment of the analysis of the final interpolated grids is in preparation.

Digital Elevation Model (DEM) locally averaged to 0.05 degree resolution and resampled to 0.01 degree resolution. This is used to support spatial modelling of precipitation and related surface processes that have a coarser resolution interaction with surface topography (Sharples et al. 2005). Derived by calculating a 0.05 degree DEM consisting of 0.05 degree local averages of values from the GEODATA 9 second DEM version 3 (Hutchinson et al. 2008). These 0.05 degree grid values were then smoothly resampled to 0.01 degree resolution using biquadratic spline interpolation.

Mean daily incident solar radiation of each month, for the Australian continent between 1970-2016. Monthly solar radiation regulates rates of plant growth. Modelled by expressing observed monthly solar radiation as normalised anomalies with respect to a standard Angstrom equation that expresses monthly solar radiation in terms of astonomically determined parameters and relative sunshine duration, as described in Hutchinson et al. (1984). The monthly anomalies were interpolated by trivariate thin plate smoothing spline functions of longitude, latitude and the proportion of wet days in the month using ANUSPLIN Version 4.5. This anomaly method provided a more direct, and more statistically robust, representation of the impact of precipitation on solar radiation than the method described in Hutchinson et al. (1984). The proportion of wet days, as provided by ANUClimate_v1-0_rainfall-proportion-greater-than-threshold_monthly_0-01deg_1970-2016, acted as simple surrogate for relative sunshine duration. There were on average 645 observed solar radiation totals for each month between 1970 and 1996 at 64 stations across Australia obtained from the Bureau of Meteorology. Automated quality assessment rejected on average 9 data values per month with extreme studentised residuals. The root mean square of all individual cross validation residuals provided by the spline analysis is 1.15 MJ m-2 day-1 (6% of the mean). A comprehensive assessment of the analysis and the factors contributing to the quality of the final interpolated monthly solar radiation grids is in preparation.

Mean daily minimum temperature of each month, for the Australian continent between 1970-2016. Daily temperature regulates rates of plant growth and determines critical conditions such as frost on flowering and fruiting. Modelled by expressing each monthly value as a difference anomaly with respect to the gridded 1976-2005 mean daily minimum temperature for each month as provided by ANUClimate_v1-0_temperature-min_monthly-mean_0-01deg_1976-2005. The monthly anomalies were interpolated by trivariate thin plate smoothing spline functions of longitude, latitude and vertically exaggerated elevation using ANUSPLIN Version 4.5. Monthly data values were calculated from Bureau of Meteorology daily data at stations where there were at least 25 days of record, giving an average of 634 data points per month between 1970 and 2016. Automated quality assessment rejected on average 2 data values per month with extreme studentised residuals. The root mean square of all individual cross validation residuals provided by the spline analysis is 0.73 degrees Centigrade. A comprehensive assessment of the analysis and the factors contributing to the quality of the final interpolated grids is in preparation.

Daily solar radiation for the Australian continent between 1970-2014. Daily solar radiation regulates rates of plant growth and crop yield. Modelled by expressing each daily value as a ratio of the external to the atmosphere value and then modelling this ratio as a function of longitude, latitude, normalised daily temperature range and daily rainfall using ANUSPLIN Version 4.5. Daily solar radiation data between 1970 and 1996 for 39 Bureau of Meteorology stations were used for the analysis after rejecting stations with short records or with many missing records. Cross validation residuals for all accepted data points had a mean absolute value of 2.3 MJ per square metre per day and a root mean square value of 3.3 MJ per square metre per day. These corresponded to relative errors of around 12% and 17% respectively. A comprehensive assessment of the analysis and the factors contributing to the quality of the final interpolated solar radiation grids is in preparation.

Annual radiation of wettest month for the Australian continent. Modelled by using ANUSPLIN Version 4.5 to fit trivariate thin plate smoothing spline functions of longitude, latitude and vertically exaggerated elevation. Station elevations were 0.05 degree local averages of grid values from the GEODATA 9 second DEM version 3 as provided by eMAST_ANUClimate_fx_el05_v1m0.

Monthly mean daily maximum temperature for the Australian continent between 1976-2005. Daily maximum temperature regulates rates of plant growth. Modelled by fitting trivariate thin plate smoothing spline functions of longitude, latitude and vertically exaggerated elevation to observed and estimated monthly 1976-2005 daily maximum temperature means at 1541 Bureau of Meteorology stations. Missing monthly temperature values were estimated by regression with the long term station that provided estimates of the 1976-2005 monthly means with with the least standard error. This was applied to each station with at least 5 years of record between 1921 and 2012. Quality controls were applied to the regression and the surface fitting processes to remove poor quality data. Thus, of 1597 stations with at least 5 years of record, 38 stations had poor regressions with long term stations and a further 18 stations had extreme studentised residuals from initial spline analyses. These were commonly stations with an old or short period of record, or with an imprecise location. The spline analysis also incorporated the impact of distance from the coast as provided by eMAST_ANUClimate_fx_dist_v1m0. The root mean square error of individual cross validation residuals provided by the spline analysis at 225 stations with near complete records, of at least 28 years, is 0.47 degrees Celsius. The incorporation of distance from the coast reduced overall cross validation errors by around 10%. A comprehensive assessment of the analysis and the factors contributing to the quality of the final interpolated monthly mean daily maximum temperature grids is in preparation.