Near-Real Time Satellite Products to Drive Australia-Wide Land Surface Monitoring and Modelling of Surface Water and Energy Balance

Abstract

The Bureau of Meteorology continuously acquires low resolution multispectral image data, with continental coverage of Australia in near-real time, from both the Advanced Very High Resolution Radiometer (AVHRR) on the US National Oceanic and Atmospheric Administration (NOAA) polar orbiting satellites and from the geostationary imagers on Japan’s MTSAT-1R and China’s Fengyun-2C satellites. The Bureau routinely derives several products from these satellites which can serve as continuous data streams that can contribute to operational land surface monitoring, either directly or as inputs (drivers or constraints) to land surface models. Solar radiation, in the form of fields of integrated daily solar horizontal exposure, is produced daily from MTSAT-1R visible-band data. A 17-year climatology of daily solar radiation has recently been produced by processing archived satellite data from 1990 to 2006, and will find application in agriculture, solar energy planning, building design, and surface energy balance studies. The Bureau is implementing operational production of Normalised Difference Vegetation Index (NDVI) and land surface temperature (LST) from AVHRR data using the Common AVHRR Processing System (CAPS) software developed by CSIRO, for use in applications that require national monitoring of vegetation condition. All of these products are produced on a 0.05° national grid: at least once per day for LST, daily for solar exposure, and weekly for NDVI. The AVHRR data products and solar exposure can together serve as near-real time continental inputs to systems for the assessment of surface moisture status across Australia, based either on simple surface energy balance models or more complex land surface models. The Australian Water Availability Project, a collaboration between the Bureau of Rural Sciences, CSIRO and the Bureau of Meteorology, is using such an approach with the data streams described to establish national monitoring of land surface water availability.