- 期刊
武夷山地形對華南春季冷鋒結構影響之個案模擬研究
The Effect of Topography on the Structure of Spring-time Cold Front
摘要
The PSU/NCAR mesoscale model (MM5) was used to investigate the topographical effect on the structure of a Spring-time cold front passing East China during 17-22 March 1998. The observational analysis shows that the surface frontal system will be retarded and deformed by the topography, when the cold front moves southward to the Wu-I Mountain Range. The cold front experiences a frontolysis process when it climbs up the mountain, and becomes frontogenesis after the cold front passes the mountains climax. The lifting of the cold front by the mountains favors the moisture in the warm sector to reach saturation. Also, the baroclinicity of the cold front remains steady during and after the front passed the mountains. Both of these two conditions are all consistent with the conditional symmetric instability (CSI) theory. Through the analysis of the moist potential vorticity (MPV), saturation condition and vertical motion, the result shows that the suitable regions for CSI to develop are distributed over the warm side of frontal band. So, the topographical effect plays an important role in the formation and distribution of CSI in frontal band.
並列摘要
The PSU/NCAR mesoscale model (MM5) was used to investigate the topographical effect on the structure of a Spring-time cold front passing East China during 17-22 March 1998. The observational analysis shows that the surface frontal system will be retarded and deformed by the topography, when the cold front moves southward to the Wu-I Mountain Range. The cold front experiences a frontolysis process when it climbs up the mountain, and becomes frontogenesis after the cold front passes the mountains climax. The lifting of the cold front by the mountains favors the moisture in the warm sector to reach saturation. Also, the baroclinicity of the cold front remains steady during and after the front passed the mountains. Both of these two conditions are all consistent with the conditional symmetric instability (CSI) theory. Through the analysis of the moist potential vorticity (MPV), saturation condition and vertical motion, the result shows that the suitable regions for CSI to develop are distributed over the warm side of frontal band. So, the topographical effect plays an important role in the formation and distribution of CSI in frontal band.