AWRA collection

Modelled daily average canopy conductance (mm per second, averaged over a day) using the Australian Water Resources Assessment model via assimilation of satellite soil moisture products: 97.5th percentile of the ensemble of model estimates. Note that the data represents the mean of an ensemble of 100 modelled estimates for each data derived via perturbed meteorological forcing. Resolution of the output data is 0.05-degree for the whole country.

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).

Precipitation of warmest quarter for the Australian continent. Warmest quarter is the set of 3 consecutive months for which the mean temperature over the selected period is higher than any other set of 3 consecutive months. Modelled using eMAST-R-Package 2.0

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.

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.

Mean temperature of warmest quarter for the Australian continent. Warmest quarter is the set of 3 consecutive months for which the mean temperature over the selected period is higher than any other set of 3 consecutive months. Modelled using eMAST-R-Package 2.0

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.