Frontogenesis, Evolution and the Time Scale of Front Formation

Observational study shows that, in some cases, the frontal structure displays the features of gravitative flows. It seems shat the formation of discontinuity is an important problem in the study of the frontogenesis which is usually defined as an increasing of the scalar gradient. In this paper, the characteristic features of air flow with initial imbalance between the wind and the density fields are studied. Much attention is paid on the condition for the forma-tion of discontinuity and its time scale. It is found that the initial distribution of density plays an important role in the formation of the discontinuity which happens in short time duration.