Surface influences on the Australian West Coast Trough

Summary  Three dimensional numerical simulations of the Australian West Coast Trough were conducted using a mesoscale model. These simulations represent the process of formation, development and disappearance of the trough and highlight the role of surface features in trough behaviour. Strong land surface heating strengthens the trough whereas topography and sea surface temperatures are of marginal importance. Diurnal variations in surface heating between the land and ocean lead to the trough line oscillating around the coast whereas its more general eastward movement is synoptically controlled. The sea breeze circulation influences local trough orientation through maritime cooling. Received December 23, 1999 Revised November 7, 2000