IHOP试验关于对流风暴的触发和演变机制总结：观测和模式展望（一）  

Summary of Convective Storm Initiation and Evolution during IHOP：Observational and Modeling Perspective

作　　者：JamesW.Wilson RitaD.Roberts 官晓军[2] 陈汇[2] 

机构地区：[1]NationalCenterforAtmosphericResearch,Boulder,Colorado [2]福建省气象台,福州350001

出　　处：《福建气象》2012年第2期11-18,共8页

摘　　要：国际H20项目试验（IHOP_2002）在试验期间，对对流风暴的触发和演变机制进行了研究。风暴的启动事件（initiationepisodes，即触发事件）大致可分为两类，一类是由地面辐合线触发，另一类地面无明显辐合，由抬升触发，前者多发生在午后和前半夜，后者则主要发生在夜间。地面触发型个例通常与天气尺度的锋面及阵风锋有关，干线和涌潮（bores）触发的较少，高空抬升型个例在RUC的900—600hPa风场分析中，通常具有明显的辐合或汇流特征。RUCl0（RUC网格距为10km的版本）对触发事件的3h降水进行预报，在空间误差250km以内及降水时间允许提前3h的条件下，准确率达到44％。但是，这个准确率跟风暴的触发机制有密切关系，对于具有天气尺度的锋面特征的个例，准确率最高，与阵风锋有关的则准确率最低。阵风锋是影响初生风暴后期演变的主要因素，几乎有一半的风暴复合体没有在地面形成阵风锋，而没有阵风锋的风暴系统只能存活2—6h，有阵风锋的至少能维持8h。大型且生命史长的风暴复合体通常具有发展完好且强大的阵风锋，并且它会影响风暴系统的传播。总体而言，RUCIO对大型和较强的风暴复合体的演变和移动预报并不成功，可能的原因是模式没能捕捉到阵风锋这一特征。本文主要针对对流风暴的触发和演变机制得出了一些结论。The International H20 Project （IHOP_2002） experiment is used to study convective storm initiation and subsequent evolution. Initiation episodes were almost evenly divided between those triggered along surface-based convergence lines and elevated initiation episodes that showed no associated surface convergence. The elevated episodes occurred mostly at night, and the surface-based episodes occurred during the afternoon and evening. Surface-based initiations were mostly associated with synoptic fronts and gust fronts and less so with drylines and bores. Elevated initiations were frequently associated withGust fronts were a primary feature influencing the evolution of the initiated storms. Almost one-half of the storm complexes associated with initiation episodes did not produce surface gust fronts. Storm systems that did not produce gust fronts most often lived 2-6 h while those that did frequently lived at least 8 h. The largest and longest-lived storm complexes had well-developed intense gust fronts that influenced the propagation of the storm system. The RUC10 was generally not successful in forecasting the evolution and motion of the larger, more intense storm complexes; presumably this was because it did not produce strong gust fronts.Implications for forecasting convective storm initiation and evolution are discussed.

关 键 词：对流风暴 触发事件 地面触发 高空触发 阵风锋 

分 类 号：P425.54[天文地球—大气科学及气象学]