[关键词]
[摘要]
在2006年6月1日发生在东海的爆发性气旋的天气学分析基础上,进行数值模拟,以进一步认识其爆发性发展的物理机制。结果表明:这次东海气旋的地面系统来自台湾岛附近的海上倒槽,在浙北沿海遇到高空比较深厚的低槽,大尺度高空槽通过槽前正涡度输送和槽前后冷暖平流对斜压不稳定的加强作用为气旋发展和维持提供有利的环境。同时,高空急流也通过其出口区的辐散和暖平流为气旋发展和维持提供有利的环境。中低层在舟山海域的强涡度平流的抬升作用产生降水,并通过水汽凝结引起潜热释放,进一步造成地面气旋系统的发展,此时气旋和降水形成正反馈机制。潜热释放被高空槽前斜压不稳定和急流出口区右侧辐散共同引起的上升运动激发后,对气旋的发展起着重要作用。
[Key word]
[Abstract]
A synoptic analysis and numerical simulation are conducted on an explosive cyclone happened on the East China Sea on 1 June 2006, in order to further understand the physical mechanisms of the cyclone explosive development. The results show that: the main influencing system on the surface is an inverse trough from the sea area around Taiwan Islands, which encountered a strong upperlevel trough over the northern coastal area of Zhejiang. The largescale upperlevel trough provided a conducive environment for cyclone development and maintenance by positive vorticity transport before the trough and the strengthening role of cold and warm advection on baroclinic instability. At the same time, a highaltitude jet provided a favorable environment for the development and maintenance of the cyclone through divergence and warm advection around its exit. The uplifting role of strong vorticity advection in middle and lower levels induced precipitation, and the latent heat release produced by water vapor condensation strengthened the development of the ground cyclone system, during which cyclone and precipitation constituted a positive feedback mechanism. The latent heat release was excited by the uplifting movement caused by the baroclinic instability before the highaltitude trough and divergence around the exit of the jet on the right side, which played an important role in the cyclone development.
[中图分类号]
[基金项目]
浙江省气象局和舟山市科委课题“海上低压大风预报方法研究”资助