Numerical test of coastal frontogenesis

A two-dimensional mesoscale model is used to investigate the effect of background wind field and character of the underlying surface on the coastal frontogenesis along the east continental coast when cold air outbreak. The results of numerical experiments indicate that the coastal frontogenesis mainly appears near ground at night. When the background wind is easterly, it is favorable to coastal frontogenesis in the lower layer of the atmosphere. When the background wind is westerly, it is unfavorable to coastal frontogenesis in the lower layer of the atmosphere. The vertical shear of the background wind has important influence on the coastal frontogenesis. The coastal frontogenesis at lower layer at night is strengthened with increasing temperature difference between sea and air. The effect of coastal sloping terrain on the coastal frontogenesis is little when the topography sloping angle is lesser.
The analysis of the physical mechanism of frontogenesis shows that the main factor influencing the coastal frontogenesis is the deformation field of horizontal wind speed.