水平对流卷研究进展

A review of research progress on horizontal convective rolls

中文关键词:  水平对流卷，外场试验，数值模拟，冷流雪，深对流

英文关键词:Horizontal convective rolls,Field experiment,Numerical simulation,Cold-flow snowstorm,Deep convection

中文摘要:

      [目的]水平对流卷（Horizontal convective rolls，HCR）被定义为发生在对流边界层内反向旋转的水平涡管，是大气层常见的浅对流形式之一。HCR会引起边界层内湍流和水汽强烈混合，以及边界层与自由大气间物质、动量和热量的交换。[资料和方法]气象学家通过外场观测试验、理论推导、水槽试验和数值模拟对HCR的结构特征、形成机理、对边界层的影响开展了系统性研究。[结果]结果表明拐点不稳定和条件不稳定是HCR形成的主要机制。HCR的湍流通量输送会引起边界层在水平方向上的通量非均匀分布，HCR上升支的垂直运动、高比湿和温度正异常为冷流雪和深对流提供了的有利条件。目前大涡模拟是研究HCR的主要数值模拟手段。[结论]然而，HCR引发强降雪、HCR独立触发深对流的机理仍不清楚。建议未来加快新型遥感技术在外场试验中的应用，构建HCR三维结构模型；开展冷流雪过程的穿云试验，研究HCR的气溶胶和通量输送对冰相微物理过程的影响；在对能否触发深对流的HCR结构特征及环境条件对比分析的基础上，发展一个简便高效的HCR触发深对流临近预报模式或业务流程，旨在提升HCR引发灾害性天气的业务预报水平。

英文摘要:

      Horizontal convective rolls (HCRs) are defined as horizontal vortices that rotate in the opposite direction within the convective boundary layer. They are one of the common forms of shallow convection in the atmosphere. HCRs can cause strong turbulence and water vapor mixing in the boundary layer, as well as the exchange of material, momentum, and heat flux between the boundary layer and the free atmosphere. Meteorologists have conducted systematic research on the structural characteristics, formation mechanisms, and impact on the boundary layer of HCR through field observation experiments, theoretical derivation, flume experiments, and numerical simulations. The results indicate that inflection-point instability and thermal instability are the main mechanisms for the formation of HCRs. The turbulent flux transport of HCRs can cause non-uniform distribution of flux in the horizontal direction of the boundary layer. The vertical motion, high specific humidity, and positive temperature anomalies of the HCRs ascending branch provide favorable conditions for cold-flow snowstorm and deep convection. At present, large eddy simulation is the main numerical simulation method for studying HCRs. However, the mechanism by which HCRs triggers heavy snowfall and HCRs independently triggers deep convection is still unclear. To accelerate the application of new remote sensing technology in field experiments to establish three-dimensional structural model of HCRs. Conduct cloud penetration experiments on cold flow snow processes to study the effects of HCRs aerosols and flux transport on ice microphysical processes. To develop a simple and efficient HCRs triggering deep convection nowcasting model or operation process based on the comparative analysis of the structural characteristics of HCRs and environmental conditions that can trigger deep convection. Aim to improve the operational forecasting level of catastrophic weather caused by HCRs.