With the aid of the Penn State-NCAR MM5 model, the initiation mechanism of meso-β scale convective systems (MCS) is investigated on the basis of simulation of the temporal and spatial thermodynamic structure ...With the aid of the Penn State-NCAR MM5 model, the initiation mechanism of meso-β scale convective systems (MCS) is investigated on the basis of simulation of the temporal and spatial thermodynamic structure of the MCS that occurred in Wuhan, Hubei, China and its surrounding area on 21 July 1998. Using the PV inversion method, comparisons among the upper-, middle-, and low-level tropospheric potential vorticity (PV) perturbations, as well as their effects on the initiation of MCS, indicate that the low-level tropospheric PV perturbations play an important role in the triggering of MCS. Further analysis reveals that the interaction between the southwest low-level jet and the gravity-inertia wave indeed initiates MCS in the conditionally unstable ambient atmosphere.展开更多
Numerical simulation and diagnosis show that the amplified rainstorm from Typhoon Poily is related to the development/migration of meso-α gravity waves, inhomoseneous stratification distribution andcumulus convection...Numerical simulation and diagnosis show that the amplified rainstorm from Typhoon Poily is related to the development/migration of meso-α gravity waves, inhomoseneous stratification distribution andcumulus convection latent heating feedback in the storm; such waves at a large scale are excited bylarge-scale nonlinear advection; substantially amplified ageostrophic wind perturbation resulting fromthe latent heating gives rise to intensified wave amplitude, leading to enhanced rising and thus torrentialrainfall; as the waves migrate towards reduced stability, wave energy is most likely to increase.展开更多
基金The authors are very grateful to Prof. Tan Zhemin, Dr, Fang Juan, Dr. Xiang Jie, and Dr.Wang Chunming for their beneficial discussions, We are deeply indebted to the reviewers for their helpful comments and criticism on an earlier manuscript.This work was sponsored by the Nanjing University Postdoctoral Foundation,the Science Foundation of Jiangsu Province Education Bureau (00KJB170001)NSF of Jiangsu(BK99020),the State Key Basic Program: CHERES, and the National Natural Science Foundation of China under Grant No.4007501l.
文摘With the aid of the Penn State-NCAR MM5 model, the initiation mechanism of meso-β scale convective systems (MCS) is investigated on the basis of simulation of the temporal and spatial thermodynamic structure of the MCS that occurred in Wuhan, Hubei, China and its surrounding area on 21 July 1998. Using the PV inversion method, comparisons among the upper-, middle-, and low-level tropospheric potential vorticity (PV) perturbations, as well as their effects on the initiation of MCS, indicate that the low-level tropospheric PV perturbations play an important role in the triggering of MCS. Further analysis reveals that the interaction between the southwest low-level jet and the gravity-inertia wave indeed initiates MCS in the conditionally unstable ambient atmosphere.
文摘Numerical simulation and diagnosis show that the amplified rainstorm from Typhoon Poily is related to the development/migration of meso-α gravity waves, inhomoseneous stratification distribution andcumulus convection latent heating feedback in the storm; such waves at a large scale are excited bylarge-scale nonlinear advection; substantially amplified ageostrophic wind perturbation resulting fromthe latent heating gives rise to intensified wave amplitude, leading to enhanced rising and thus torrentialrainfall; as the waves migrate towards reduced stability, wave energy is most likely to increase.
