摘要:基于NCEP 6 h一次，0.5°（纬度）×0.5°（经度）水平分辨率的GFS（Global Forecasting System）再分析数据，利用数值模式WRF（Weather Research and Forecasting），对2014年11月上旬西北太平洋一次极端强度的爆发气旋事件进行了模拟。在成功复制爆发气旋主要特征的基础上，较详细的分析了本次爆发气旋快速发展的有利环境条件，并利用分片位涡反演的方法，对此次爆发气旋的快速发展过程进行了研究，主要结论如下：（1）本次爆发气旋的爆发性发展阶段维持了约27 h，其最大加深率约为3.98 Bergeron（气旋加深率单位），最低中心气压约为919.2 hPa。（2）爆发气旋的快速发展与对流层高层高空急流对热量的输送，对流层中层西风带短波槽槽前暖平流和正涡度平流的有利准地转强迫，以及对流层低层暖锋伴随的暖平流过程密切相关。（3）分片位涡反演的结果表明，对流层顶皱褶对应的平流层大值位涡下传和降水凝结潜热过程造成的正位涡异常是本次爆发气旋快速发展的主导因子，而对流层低层的斜压过程贡献相对较小。在气旋爆发期的前期和强盛期，降水凝结潜热释放是爆发气旋发展的最重要因子，而在爆发期后期，随着降水的减弱和爆发气旋的东北向移动，对流层顶皱褶作用所造成的正位涡异常成为维持气旋快速发展的最有利因子。
关键词:爆发气旋/
分片位涡反演
Abstract:On the basis of the 6-hourly NCEP GFS (Global Forecasting System) reanalysis data with a horizontal resolution of 0.5°, an extreme explosive cyclone event occurred in early November 2014 is simulated using the WRF (Weather Research and Forecasting) model. After the key features of this extreme event are well reproduced by the WRF model, this study analyzes the environmental conditions favorable for the rapid development of the cyclone, and investigates the mechanisms for the explosive development of the cyclone using the piecewise potential vorticity inversion method. Main results are as follows:(1) The explosive development of this cyclone lasted for 27 h with a maximum deepening rate of 3.98 Bergeron (unit of cyclone deeping rate), and a minimum central SLP (Sea Level Pressure) of 919.2 hPa. (2) The rapid development of the explosive cyclone was closely related to heat transport by the upper-level jet stream in the upper troposphere, the quasi-geostationary forcing (e.g., warm advection and cyclonic vorticity advection) ahead of a shortwave trough in the middle troposphere and the warm advection accompanied by the warm front in the lower troposphere. (3) The result of piecewise potential vorticity inversion shows that the tropopause-folding-related downward transport of large-value potential vorticity in the stratosphere and the precipitation-condensation-related diabatic heating governed the rapid development of this explosive cyclone, while the baroclinic process in the lower troposphere made the smallest contribution. In the early and middle stages of the explosive development period, the latent heat release is the most important factor for the cyclone's development. In contrast, in the late stage of the explosive development period, because the precipitation weakened and the cyclone entered a strong tropopause folding region, the tropopause folding became the most favorable factor for maintaining the rapid development of the cyclone.
Key words:Explosive cyclone/
Piecewise potential vorticity inversion
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