Spanish Plume Literature Review and Case Studies

The Spanish plume is a synoptic pattern associated with deep moist convective storms in western and central Europe. A large-amplitude trough or cut-off low in the jet stream extending to low latitudes produces a long fetch of southerly or southwesterly flow in the lower troposphere across the Iberian Peninsula and into Europe. The preconvective environment is traditionally characterized by an elevated mixed layer of hot dry air with steep lapse rates (i.e., the Spanish plume airstream) overtop a warm surface layer and capping inversion, resembling the loaded-gun convective sounding. A literature review of 102 peer-reviewed journal articles mentioning the Spanish plume is performed (of which 84 have only passing mentions). Some articles correctly employ the original definition of the Spanish plume airstream as the dry elevated mixed layer, whereas others incorrectly apply the term to the surface (sometimes humid) airstream. The origin of the airstream is variously described as the Iberian Peninsula, northern Africa, or both, often unevidenced. Some air in so-called Spanish plumes does not even cross Spain. Descriptions of convective storms in Spanish plume synoptic patterns also are largely unevidenced, with release of instability attributed to various synoptic-scale and mesoscale processes. This review reveals these and other issues with the literature on the Spanish plume, painting a sometimes unevidenced, inconsistent, unclear, and inaccurate picture. The goals are to recommend proper usage of the term Spanish plume and articulate future research questions, specifically related to quantifying interactions with terrain through diurnal sensible heat fluxes and orographic flow modification to produce favorable environments for convective storms. This dataset contains the list of 102 journal articles used in this study and data from case studies of Spanish plume events.

西班牙羽流（Spanish plume）是一种与西欧和中欧深厚湿对流风暴相关的天气尺度环流型。急流中延伸至低纬度的大振幅槽或切断低压，会在对流层低层形成长距离输送的南风或西南风气流，横跨伊比利亚半岛并进入欧洲大陆。传统而言，对流前环境的典型特征为：暖地面层上方存在由干热空气构成的抬升混合层，搭配大直减率（即西班牙羽流气流）与逆温盖，整体形态类似装弹型对流探空。

本研究对102篇提及西班牙羽流的同行评议期刊论文开展了文献综述，其中84篇仅对该概念进行了顺带提及。部分论文正确采用了西班牙羽流气流即干抬升混合层的原始定义，另有部分论文则错误地将该术语用于指代地面气流（有时为湿润气流）。该气流的起源被分别归因于伊比利亚半岛、北非或两者兼具，但相关描述大多缺乏实证支撑。甚至有部分被归类为西班牙羽流的气流甚至未途经西班牙上空。

针对西班牙羽流天气型下对流风暴的相关描述，同样大多缺乏实证支撑，且将不稳定能量的释放归因于各类天气尺度与中尺度过程。本次综述揭示了西班牙羽流相关研究中的上述及其他问题，整体呈现出一种时常缺乏依据、表述不一、概念模糊且存在谬误的研究图景。

本研究的目标在于为西班牙羽流术语的规范使用提供建议，并阐明未来的研究方向，具体包括通过日感热通量量化地形相互作用，以及地形流场改造对对流风暴有利环境的影响机制。本数据集包含本研究使用的102篇期刊论文列表，以及西班牙羽流事件的个例研究数据。