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 total class A pan evaporation for the Australian continent between 1976-2005. Class A pan evaporation is useful for estimating evaporation rates and water need and use. Modelled by fitting trivariate thin plate smoothing spline functions of longitude, latitude and vertically exaggerated elevation to the square roots of observed and estimated monthly 1976-2005 pan evaporation means at 444 Bureau of Meteorology stations. Quality controls were applied to the regression and the surface fitting processes to remove poor quality data. Thus, of 468 stations with at least 5 years of record, 19 stations had poor regressions with long term stations and a further 5 stations had extreme studentised residuals from initial spline analyses. 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. Missing monthly values were estimated by regression with the long term station that provided the monthly 1976-2005 means with with the least standard error. The mean absolute error of individual cross validation residuals provided by the spline analysis at 107 stations with near complete records, of at least 28 years, is 16.5 mm (11% of the mean).

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.

Monthly mean daily minimum temperature for the Australian continent between 1976-2005. Daily minimum 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 minimum 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 minimum temperature grids is in preparation.

Daily maximum temperature for the Australian continent between 1970-2014. Daily maximum temperature regulates rates of plant growth and crop yield. Modelled by expressing each daily value as a difference anomaly with respect to the gridded 1976-2005 monthly mean daily maximum temperatures as provided by ANUClimate_v1-0_temperature-max_monthly-mean_0-01deg_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 675 Bureau of Meteorology data points available for each day between 1970 and 2014. Automated quality assessment rejected on average 2.6 data values per day with extreme studentised residuals. These were commonly associated with days following missing observations. Cross validation residuals for all accepted data points had a mean absolute value of 0.76 degrees Celsius and a root mean square value of 1.06 degrees Celsius. A comprehensive assessment of the analysis and the factors contributing to the quality of the final interpolated daily maximum temperature grids is in preparation.

Monthly total precipitation of each month, for the Australian continent between 1970-2016. Monthly rainfall totals are useful for estimation of soil moisture for plant growth and surface runoff via soil water balance modelling. Modelled by expressing each monthly value as a normalised anomaly with respect to the gridded 1976-2005 mean for each month as provided by ANUClimate_v1-0_rainfall_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. 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. Monthly data values were calculated from Bureau of Meteorology daily data at stations where there were no missing observations and any accumulated records were wholly within the month, giving an average of 6410 data points per month between 1970 and 2016. Automated quality assessment rejected on average 16 data values per month (0.2%) with extreme studentised residuals. The mean absolute value of all individual cross validation residuals provided by the spline analysis is 10.9 mm (18% of the overall mean). A comprehensive assessment of the analysis and the factors contributing to the quality of the final interpolated monthly rainfall grids is in preparation.

Daily total precipitation for Australian continent between 1970-2014. Daily rainfall totals are useful for estimation of soil moisture for plant growth and surface runoff via soil water balance modelling. Modelled by expressing each daily value, including zero rainfall, as a normalised anomaly with respect to the gridded 1976-2005 mean for each month, as provided by ANUClimate_v1-0_rain_monthly-mean_0-01deg_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. 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_dem05_terrain_0-01deg. There was an average of 6384 Bureau of Meteorology data points per day between 1970 and 2014. The mean absolute value of all individual cross validation residuals provided by the spline analysis is 0.95 mm (50% of the overall mean). Extreme studentised residuals clearly identified data errors associated with unrecognised missing values, unrecognised accumulated values, and values recorded on the wrong (usually preceding) day. There were on average around 5 such extreme residuals per day. The rainfall occurrence of the individual cross validated days agrees with the rainfall occurrence of 91% of all days of record, where daily rainfall occurrence is defined as daily rainfall exceeding 0.2 mm. A comprehensive assessment of the analysis and the factors contributing to the quality of the final interpolated monthly rainfall grids is in preparation.

Mean daily maximum 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 maximum temperature for each month as provided by ANUClimate_v1-0_temperature-max_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.

Monthly mean daily vapour pressure of each month, for the Australian continent between 1970-2016. Daily vapour pressure regulates evaporation rates and water need and use. Modelled using ANUSPLIN Version 4.5.

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.