Daily mean vapour pressure: ANUClimate 1.1, 0.01 degree, Australian Coverage, 1970-2014

Abstract

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.