A Simple Model of the Australian West Coast Trough

Abstract

The Australian west coast trough forms near the west coast in the easterly flow over Australia in the warmer months of the year. Its development and movement is the major synoptic influence on the weather in those months, particularly in the production of extreme maximum temperatures and subsequent ?cool changes.? This paper begins with a brief discussion of the climatology of the trough, followed by a case study. The main focus is on the development and interpretation of a simple dynamical model of the trough. The model is an adaptation of the linear diabatic equatorial ?-plane models of Matsuno and of Gill for the particular situation of the trough. The study leads to a new hypothesis on the role of the sea breeze in the dynamics of the trough.