Observations of the Discrete Propagation of a Mesoscale Convective System during RELAMPAGO–CACTI
Observations of the Discrete Propagation of a Mesoscale Convective System during RELAMPAGO–CACTI
复制标题
RELAMPAGO—CACTI 期间中尺度对流系统离散传播的观测
DOI：
10.1175/mwr-d-21-0265.1
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发表时间：
2022
影响因子：
3.2
通讯作者：
Kumjian, Matthew R.
中科院分区：
文献类型：
--
作者：
Lombardo, Kelly;Kumjian, Matthew R.
2018年11月5日清晨，在自适应地面观测-云，气溶胶和复杂地形相互作用（RELAMPAGO-CACTI）联合实地活动中，一个成熟的中尺度对流系统（MCS）在阿根廷人口第二多的省份科尔多瓦省离散传播。位于该省西部的一条南北走向的区域山脉--科尔多瓦山脉改变了风暴的活动。在这里，我们提出的离散传播事件的观测证据和山脉对相关的物理过程的影响。当成熟MCS向东北方向移动并靠近山脉迎风面时，在山脉背风面下游发展出孤立的对流单体，比主对流线提前20-50 km。细胞发起的波状孔，形成的MCS冷池移动到山脊上，扰动背风夜间，低层稳定层。孤立的单体组成了一个新的MCS，继续向东北方向移动，而母风暴在穿越山脉时已经衰减。由于沿着山脉高度的变化，风暴只有南部部分离散传播。在北部，较高的山峰阻止MCS冷池在地形上移动并扰乱稳定层。因此，没有产生孔，并且在该区域中没有发生离散传播。在南方，MCS冷池能够穿越地势较低的山脉，离散传播是成功的。
During the early morning hours of 5 November 2018, a mature mesoscale convective system (MCS) propagated discretely over the second-most populous province of Argentina, Córdoba Province, during the Remote Sensing of Electrification, Lightning, and Mesoscale/Microscale Processes with Adaptive Ground Observations–Cloud, Aerosol, and Complex Terrain Interactions (RELAMPAGO–CACTI) joint field campaigns. Storm behavior was modified by the Sierras de Córdoba, a north–south-oriented regional mountain chain located in the western side of the province. Here, we present observational evidence of the discrete propagation event and the impact of the mountains on the associated physical processes. As the mature MCS moved northeastward and approached the windward side of the mountains, isolated convective cells developed downstream in the mountain lee, 20–50 km ahead of the main convective line. Cells were initiated by an undular bore, which formed as the MCS cold pool moved over the mountain ridge and perturbed the leeside nocturnal, low-level stable layer. The field of isolated cells organized into a new MCS, which continued to move northeastward, while the parent storm decayed as it traversed the mountains. Only the southern portion of the storm propagated discretely, due to variability in mountain height along the chain. In the north, taller mountain peaks prevented the MCS cold pool from moving over the terrain and perturbing the stable layer. Consequently, no bore was generated, and no discrete propagation occurred in this region. To the south, the MCS cold pool was able to traverse the lower-relief mountains, and the discrete propagation was successful.