Bluelink: ROAM (2002-Current)

For more information about ROAM, see the Bluelink website

ROAM (Relocatable Ocean and Atmospheric Model) is a suite of regional ocean, atmosphere, wave and littoral zone modelling systems that enable high resolution forecasts in user-configured subdomains that are nested within the global model outputs.

There are a number of scientific and engineering challenges in the design and implementation of ROAM.

ROAM is intended to deliver forecasts on a first-time-every-time basis; i.e. model instability and optimisation of model parameters via iterative simulations cannot be accepted. This makes the automated parameterisation a challenge; the model must be robust enough to deliver a stable simulation, but accurate enough to provide meaningful results. The open boundaries of regional domains are particularly challenging in this regard. Furthermore, the system is operated by non-specialist users on a web interface. This makes intuitive interface design a key part of the project.

ROAM has been successfully implemented on numerous domains within the Australasian region (Figure 1). The added skill of ROAM-Ocean in comparison to the global model is illustrated in Figures 2 and 3, where most of the added value is due to the inclusion of the tide in this case. The higher resolution used in ROAM-Ocean results in the added spatial detail illustrated in Figure 4.

 

Some regions ROAM has been applied to.
Figure 1: Some regions ROAM has been applied to.

 

Surface currents and salinity comparison between OFAM and ROAM for the south-east Australian coast. OFAM (an implementation of the MOM4 ocean code) is the underlying global ocean model used in BlueLINK.
Figure 2: Surface currents and salinity comparison between OFAM and ROAM-Ocean for the south-east Australian coast. OFAM is the underlying global ocean model used in Bluelink’s operational forecasts (OceanMAPS, delivered by the Bureau of Meteorology).

 

Detail of the surface salinity comparison between OFAM and ROAM on the south-east coast of Australia.
Figure 3: Detail of the surface salinity comparison between OFAM and ROAM-Ocean on the south-east coast of Australia.

 

Surface temperature comparison between OFAM and ROAM on the North West Shelf of Australia.
Figure 4: Surface temperature comparison between OFAM and ROAM-Ocean on the North West Shelf of Australia.
For more information about ROAM, see the Bluelink website