Abstract
Severe dust storms frequently occur over northwestern China during spring. They are often associated with strong fronts. In this paper, numerical simulations are performed to examine the effect of dust radiative heating on surface frontogenesis.
The absorption and multiple scattering of the dust are included in an atmospheric radiation scheme. A two-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 temperature gradient reaches 6 K (100 km)−1, which is three times as large as that in the initial data. A direct vertical transverse circulation is established along the frontal zone. which is qualitatively similar to the observations.
The results show positive interaction between low-level frontogenesis and dust radiative heating. The adiabatic frontogenesis 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.
