The development of a sea‐breeze circulation into a sea‐breeze front in often observed late in the afternoon. Measurements of horizontal temperature and humidity profiles in a number of sea‐breeze circulation, made using an instrumented light aircraft, are presented. On each of the four days for which data are presented an initial weak horizontal temperature gradient, extending over a distance of 5 to 10 kilometres, developed later in the into a sharp front only a few hundred metres across. The data are discussed in terms of simple gravity‐current frontogenesis models applied to the development of sharp sea‐breeze front from an initial diffuse transition between the air over the land sea. Examination of the equations for frontogenesis, and the result of some previous laboratory experiments on gravity‐current frontogenesis, lead to the proposal that, given sufficient contrast between land and sea temperatures, the formation of a sea‐breeze front depends on the balance between convergent horizontal winds which act to generate a front, and turbulent convective mixing over the land which tends to prevent its formation. the differences in driving force, wind convergence and turbulent intensity are discussed for each day on which data are available and are shown to be consistent with the theory proposed.
|Number of pages||16|
|Journal||Quarterly Journal of the Royal Meteorological Society|
|State||Published - 1993|