高级搜索

山东省雷暴大风天气学分型与物理诊断量统计特征

Synoptic classification and statistical characteristics of physical diagnoses for thunderstorm gale in Shandong Province

  • 摘要: 使用MICAPS地面气象观测资料和探空资料,对山东省2009—2016年4—9月产生的雷暴大风以500 hPa天气系统为主进行分型,并以低层(850 hPa)中尺度天气系统和地面天气系统为辅对各型雷暴大风进行分类。然后,采用百分位数法统计分析各型雷暴大风发生时的物理诊断量,并给出各物理诊断量的临界值。结果表明:(1)基于500 hPa天气影响系统配置,山东省雷暴大风分为槽前型、槽后型和副高边缘型,再根据雷暴大风落区与850 hPa天气系统的位置关系,又分为切变线辐合类、偏南气流辐合类和偏北气流辐合类3种类型,而根据海平面气压场中天气系统与雷暴大风的位置关系,则将产生雷暴大风的地面天气系统主要归纳为6种类型。(2)将山东省划分为内陆地区和半岛地区,4—6月内陆地区雷暴大风的适用物理诊断量为850 hPa与500 hPa温差(ΔT850-500)、500 hPa与850 hPa风速差(ΔV500-850)、风暴强度指数(SSI)和大风指数(WI),半岛地区代表大气热力和动力综合特征的物理诊断量SSIWI对雷暴大风的指示性较好。(3)7—8月山东全省,代表大气热力不稳定的物理诊断量即对流有效位能(CAPE)、K指数、抬升指数(LI)、700 hPa与850 hPa假相当位温差(Δθse700-850)、强天气威胁指数(SWEAT),对雷暴大风有较好的指示性。(4)9月山东省雷暴大风主要发生在半岛地区,Δθse700-850SSISWEAT和ΔV500-850对雷暴大风具有较好的指示性。

     

    Abstract: In this study, we divide the region covering Shandong Province into inland and peninsula area. By using the surface meteorological observation and sounding data from the MICAPS, we have conducted a classification to the thunderstorm gale events occurred between April and September from 2009 to 2016 in Shandong Province primarily based on the 500 hPa synoptic systems. In addition, based on the mesoscale weather systems in the 850 hPa and at the surface, the different patterns of thunderstorm gale events are classified. Then the physical diagnose of each pattern of thunderstorm gale event is statistically analyzed by using the percentile method, and the critical values of these physical diagnoses are given. The results show that (1) based on the configuration of the 500 hPa weather influence systems, the thunderstorm gales in Shandong can be divided into pre-trough pattern, post-trough pattern and around subtropical high pattern. Additionally, according to the relation between the falling area of thunderstorm strong wind and the 850 hPa weather systems, they can also be divided into three types, i.e. shear line convergence, southerly airflow convergence and northerly airflow convergence. Furthermore, according to the position relationship between the weather system and the thunderstorm gale in the sea-level pressure field, the surface weather systems that generate thunderstorms high winds can be mainly divided six types. (2) The suitable physical diagnoses of thunderstorm gales between April and June in the inland area of Shandong are temperature difference (ΔT850-500) between 850 hPa and 500 hPa, velocity difference (ΔV500-850) between 500 hPa and 850 hPa, Storm Strength Index (SSI) and Wind Index (WI), while in the peninsula area of Shandong, the physical diagnoses SSI and WI, which can represent the comprehensive characteristics of atmospheric thermodynamics and dynamics, show a good indication to thunderstorm gales in this area. (3) The physical diagnoses Convective Available Potential Energy (CAPE), K index, Lift Index (LI), pseudo-equivalent potential temperature difference (Δθse700-850) between 700 hPa and 850 hPa and severe weather threat index (SWEAT), representing atmospheric thermal instability, have good indicative signification to the thunderstorm gales between July and August in Shandong province. (4) Δθse700-850, SSI, SWEAT and ΔV500-850 have good indication to the thunderstorm gales occurred in the peninsula area of Shandong in September.

     

/

返回文章
返回