Sea-breezes and waves: the ‘Kalgoorlie sea-breeze’ and the ‘Goondiwindi breeze’

The Pielke numerical model has been used to investigate the wind surge often seen in summer on Kalgoorlie (350 km inland) anemograms at about 2300 h. The evidence provided by the model shows conclusively that the Kalgoorlie surge is activated by the sea-breeze, but that by the time it reaches Kalgoorlie it has degenerated to an internal long wave propagating on the nocturnal inversion. It cannot be deduced from the model whether the long wave develops undulations near its leading edge, but such structures are likely to be a fruitful source of solitary wave trains in the continental interior. The model has proved successful in determining the origin of a summertime evening northeasterly wind surge often noticed at Goondiwindi, Queensland (315 km inland behind a range of mountains). It transpires that the sea-breeze front cannot be detected ascending the ranges. A surge starts near and to the lee of the top of the ranges in the early afternoon. It is this surge which reaches Goondiwindi at about 2100 h. By this time, however, sea air has actually penetrated inland as far as Goondiwindi. Three-dimensional modelling with orography shows that a surge line parallel to the coast reaches Goondiwindi at about 2100 h. It is a gravity current at this stage, but it also is evidently destined to degenerate, after midnight, to a long wave of elevation with solitary waves.