Implementation of the initial ACCESS numerical weather prediction system

Abstract

The Australian Community Climate and Earth-System Simulator (ACCESS) is a coupled climate and earth system simulator being developed as a joint initiative of the Bureau of Meteorology and CSIRO in cooperation with the university community in Australia. The main aim of ACCESS is to develop a national approach to climate and weather prediction model development. Planning for ACCESS development commenced in 2005 and significant progress has been made subsequently. ACCESS-based numerical weather prediction (NWP) systems were implemented operationally by the Bureau in September 2009 and were marked by significantly increased forecast skill of close to one day for three-day forecasts over the previously operational systems. The fully-coupled ACCESS earth system model has been assembled and tested, and core runs have been completed and submitted for the Intergovernmental Panel for Climate Change (IPCC) Fifth Assessment Report. Significant progress has been made with ACCESS infrastructure including successful porting to both Solar and Vayu (National Computational Infrastructure (NCI)) machines and development of infrastructure to allow usage by university researchers. This paper provides a description of the NWP component of ACCESS and presents results from detailed verification of the system.

On the Sensitivity of Tropical Cyclone Intensification under Upper-Level Trough Forcing

“…At short term (0-24 h), the best results in intensity and position forecasts are from the two limitedarea models owing to vortex bogusing. This is consistent with recent statistics obtained over the Australian region using a sample of 22 forecasts of two major TCs (see Table 4 of Davidson et al 2014): the Australian Community Climate and Earth System Simulator (ACCESS-A; Puri et al 2013) showed an average mean absolute error of 11 hPa and 117 km at the initial time of the forecast, while the average error was reduced to 7 hPa and 30 km in the version of the model that uses vortex bogusing (ACCESS-TC; Davidson et al 2014). However, at longer ranges (48-72 h), ECMWF performs better thanks to a more coherent representation of the interaction between the storms and their large-scale environments.…”

The ACCESS coupled model: description, control climate and evaluation

“…As can be seen via comparison with Fig. 1 of Puri et al (2013), the ACCESS1.3 configuration is a key step on the way to attaining a full earth system model as laid out in the original ACCESS project plan. 5 GA1.0 comprises a suite of atmospheric model implementations sharing a common physics, and, of relevance here, includes the atmospheric component of the UK Met Office's HadGEM3(r1.1) coupled model (Arribas et al2011, Hewitt et al 2011 Though the component codes may be different, the ACCESS modelling program builds on a long history of weather and climate modelling in Australia.…”

“…All these uncertainties impact our ability to project climate change at the regional level and evaluate the potential impact on the Australian community, and to respond to the risks in an informed manner. Puri et al (2013) have outlined the development of a new Australian capacity in weather and climate simulation, the Australian Community Climate and Earth System Simulator (ACCESS). A major goal of ACCESS is to provide state-ofthe-art climate modelling capacity to support Australian research aimed at addressing uncertainties such as those above.…”

Validation of a Satellite-based Fog and Low Stratus Detection Algorithm Using Himawari-8 over Australia

“…For the Bureau's implementation of the algorithm, the NWP data are primarily derived from the Australian Community Climate and Earth-System Simulator (ACCESS) model [Puri et al, 2013]. In particular, the regional version (ACCESS-R) of the model is used [National Meteorological and Oceanographic Centre, 2013].…”