Despite cold fronts being the predominate meteorological feature in the mid-lattitudes, little work has been done to determine how they are affected by boundary layer turbulence, the diurnal cycle or differential diabatic heating. The interaction of fronts with coastlines is especially important in the Southern Hemisphere as observations show frontogenesis is strongest on the western sides of the Southern Hemisphere continents. In Australia, cold fronts form in the southern ocean and are swept onshore in the southern half of the continent. This interaction with the sea-breeze can affect the timing and strength of cold fronts as they cross the coastline. In the work presented a confluent deformation model is used to examine how cold fronts are affected by sharp heating gradients associated with coastlines. The confluent deformation model is formulated in sigma co-ordinates on an f-plane and moist processes are neglected for simplicty. The boundary layer turbulence is parametrised with the Mellor-Yamada 2.25 scheme. The work examines the strength and timing of cold fronts in three cases: frontogenesis above a homogenous land surface; frontogenesis above a homogenous ocean surface; and the dynamics of a cold front as it crosses a coastline and interacts with the sea-breeze.Pages: 1857-185
