THE EFFECT OF DUST RADIATIVE HEATING ON LOW-LEVEL FRONTOGENESIS

Severe dust storms frequently occur over northwestern China during spr ing. They are often associated with strong fronts. In this paper, nume rical simulations are performed to examine the effect of dust radiativ e heating on surface frontogenesis. The absorption and multiple scatte ring of the dust are included in an atmospheric radiation scheme. A tw o-dimensional primitive equation model with 20 levels in the vertical is used for idealized simulations. After a 12-h integration, a strong narrow front zone is created below 650 mb. The horizontal potential te mperature gradient reaches 6 K (100 km)(-1), which is three times as l arge as that in the initial data. A direct vertical transverse circula tion is established along the frontal zone, which is qualitatively sim ilar to the observations. The results show positive interaction betwee n low-level frontogenesis and dust radiative heating. The adiabatic fr ontogenesis forcing is enhanced by the feedback of the dust radiative heating. These results suggest that the dust heating can significantly affect mesoscale weather systems in arid and desert regions.