摘要
利用NCEP分辨率1°×1°的再分析、常规气象观测和FY-2E红外云图资料,对2013年11月24—25日引发黄渤海大风的入海气旋发生与发展的动力过程进行诊断分析。结果表明:此次黄渤海大风天气过程是在中高纬不稳定小槽东移加深发展及东亚大槽重建中发生的。高空槽前正涡度平流在气旋初始阶段具有重要作用,在气旋爆发性发展阶段,低层温度平流显著加强,冷锋锋区的斜压性增大;高层正位涡中心向对流层中下层延伸,与低层位涡大值区上下相接。黄渤海大风区上空有较强的超低空非地转气流,Q矢量的强辐合和辐散区集中在气旋的周围。高空急流出口的北侧辐散区叠加在低空急流的气旋性辐合区,这种高低空急流耦合结构是气旋爆发性发展的动力原因。气压梯度和变压梯度是造成地面大风的主要原因,动量下传对此次黄渤海大风有一定的贡献。
Based on NCEP 1°×1° reanalysis data, conventional data and FY-2E satellite data, dynamic processes of a cyclone induced strong wind over the Yellow and Bohai Seas on November 24-25,2013 were analyzed. The re- suits show that this event occurs during the period of east moving and development of unstable short-wave trough at mid-high latitude and rebuilding of East Asian major trough. Vorticity advection plays an important role during early growth of the cyclone. Lower level temperature advection obviously strengthens in the stage of outbreak de- velopment of the cyclone and the baroclinity near cold front is enhanced. The downward propagation of potential vorticity on the top of troposphere extends to the middle and lower troposphere where potential vorticity is high. Ageostrophic wind at super-low-level is strong over the Yellow and Bohai Seas where the gale occurs. Conver- gence and divergence of Q vector concentrate around the cyclone. Northern divergence zone of upper level jet is susposed on cyclonic convergence zone of lower level jet, and this coupling structure of upper and lower jet is a dynamical reason for outbreak of the cyclone. Pressure gradient and isallobaric gradient are the main reasons for strong wind at the Yellow and Bohai Seas, and downward propagation of upper level momentum also contributes to the gale.
出处
《气象与环境学报》
2015年第6期59-67,共9页
Journal of Meteorology and Environment
基金
中国气象局小型基建项目"北方海域海洋气象精细化监测预报系统的构建"
天津市气象局科研项目(201517)共同资助
关键词
爆发性气旋
诊断分析
涡度平流
温度平流
斜压性
Outbreak of cyclone
Diagnostic analysis
Vorticity advection
Temperature advection
Baroclinity
