Geostrophic adjustment and frontogenesis are examined by means of the 2-D ARPS model. The simulation shows that.without the large-scale forcing,both the frontogenesis and frontolysis are observed during the geostrophi...Geostrophic adjustment and frontogenesis are examined by means of the 2-D ARPS model. The simulation shows that.without the large-scale forcing,both the frontogenesis and frontolysis are observed during the geostrophic adjustment process and the intensity of the front oscillates in the case of no discontinuity.The convergence (divergence) induced by the secondary circulation is the most important factor for frontogenesis (frontolysis) at the top and bottom boundaries.The amplitude and period of oscillation are dependent on the initial atmospheric stratification and the Coriolis frequency,and they are related to the inertio-gravity wave.展开更多
The development of symmetric disturbance superposed on the background field of Hoskins- Bretherton (1972) frontogenesis model is investigated by means of WKBJ approach,It is found that the forcing of large-scale defor...The development of symmetric disturbance superposed on the background field of Hoskins- Bretherton (1972) frontogenesis model is investigated by means of WKBJ approach,It is found that the forcing of large-scale deformation,the frontal circulation and the spatial-temporal variations of stability parameters (F^2,N^2,M^2) can bring about the development of symmetric disturbance, even though the frontal baroclinic flow is symmetric stable (F^2N^2-M^2=q>0),The frontogenetical process of deformation confluence zone and the ascending branch of frontal circulation are in favor of the development of symmetric disturbance,The actions of ageostrophic shear in frontal zone and the variation of stability parameters are dependent on the structure of disturbance.展开更多
基金This research was supported by the National Natural Science Foundation of China under Grants:49675259 and 49735180The National Key Basic Research Development Program:CHERES
文摘Geostrophic adjustment and frontogenesis are examined by means of the 2-D ARPS model. The simulation shows that.without the large-scale forcing,both the frontogenesis and frontolysis are observed during the geostrophic adjustment process and the intensity of the front oscillates in the case of no discontinuity.The convergence (divergence) induced by the secondary circulation is the most important factor for frontogenesis (frontolysis) at the top and bottom boundaries.The amplitude and period of oscillation are dependent on the initial atmospheric stratification and the Coriolis frequency,and they are related to the inertio-gravity wave.
基金It is supported by the National Natural Science Foundation of China.
文摘The development of symmetric disturbance superposed on the background field of Hoskins- Bretherton (1972) frontogenesis model is investigated by means of WKBJ approach,It is found that the forcing of large-scale deformation,the frontal circulation and the spatial-temporal variations of stability parameters (F^2,N^2,M^2) can bring about the development of symmetric disturbance, even though the frontal baroclinic flow is symmetric stable (F^2N^2-M^2=q>0),The frontogenetical process of deformation confluence zone and the ascending branch of frontal circulation are in favor of the development of symmetric disturbance,The actions of ageostrophic shear in frontal zone and the variation of stability parameters are dependent on the structure of disturbance.
