WATER-VAPOR TRANSFER OVER THE AUSTRALIAN CONTINENT

Abstract

For the calendar year 1956, daily observations of wind and humidity at eight atmospheric levels extending from the earth's surface up to the 400-mb level are used to compute average annual and seasonal vertically integrated horizontal water-vapor transfers at seventeen serological stations on and near the Australian continent. Computations include both total and eddy transfer and as a by-product of the investigation the total water-vapor content (precipitable water) at each station is obtained. Results are presented in the form of annual and seasonal charts showing the fields of water-vapor content and transfer. The vertical structure of these fields is discussed by means of graphs showing the distribution of water-vapor content and transfer with height at selected individual stations. Integrated total water-vapor transfers are used to estimate the convergence (net inflow) of water vapor over the eastern part of the continent and, with due allowance for changes in atmospheric storage, this is compared with the excess of measured precipitation over estimated evapotranspiration. Annual figures show good agreement between these quantities but when corresponding monthly values are compared the agreement is less satisfactory. The various uncertainties occurring in the basic data and in the methods of computation are briefly discussed, it being found that the most significant uncertainty is that due to the frequent occurrence of open-circuit (motorboating) humidity values over much of the Australian region.