Simulated Evolution and Severe Wind Production by the 25–26 June 2015 Nocturnal MCS from PECAN
Simulated Evolution and Severe Wind Production by the 25–26 June 2015 Nocturnal MCS from PECAN
复制标题
PECAN 2015 年 6 月 25 日至 26 日夜间 MCS 的模拟演化和强风产生
DOI：
10.1175/mwr-d-19-0072.1
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发表时间：
2019
影响因子：
3.2
通讯作者：
C. Ziegler
中科院分区：
文献类型：
--
作者：
M. Parker;B. Borchardt;Rachel L. Miller;C. Ziegler
2015年6月25日至26日夜间中尺度对流系统（MCS）来自平原夜间高架对流（PECAN）野外项目，在通常可能与高架对流相关的环境中产生了强风。这项工作结合了一个全物理的真实世界模拟和一个理想的单测深模拟来探索MCS的演变。最初，模拟的对流系统处于高架状态，由波状扰动维持，缺乏地表冷池。随着系统的成熟，地表外流开始出现，特别是在强降水发生的地方，地表冷池中的空气起源于4-5 km AGL。通过这一进程，MCS表现出一定程度的自组织（即依赖于MCS特定历史的结构）。冷池最终变得1.5-3.5公里深，此时被动示踪显示对流至少部分是基于表面的。在以地面为基础后不久，这两个模拟都产生了强烈的地面风，其中最强的风与嵌入的低层中涡旋及其伴随的流出浪涌和弯曲段有关。模拟中涡旋的起源很可能是系统产生的水平涡度（来自斜压性，但也可能是摩擦）在模拟mcs的流出中向下倾斜，正如许多先前的研究所争论的那样。总而言之，严重的夜间mcs可能经常类似于由冷池驱动的、基于地面的下午mcs。
The 25–26 June 2015 nocturnal mesoscale convective system (MCS) from the Plains Elevated Convection at Night (PECAN) field project produced severe winds within an environment that might customarily be associated with elevated convection. This work incorporates both a full-physics real-world simulation and an idealized single-sounding simulation to explore the MCS’s evolution. Initially, the simulated convective systems were elevated, being maintained by wavelike disturbances and lacking surface cold pools. As the systems matured, surface outflows began to appear, particularly where heavy precipitation was occurring, with air in the surface cold pools originating from up to 4–5 km AGL. Via this progression, the MCSs exhibited a degree of self-organization (i.e., structures that are dependent upon an MCS’s particular history). The cold pools eventually became 1.5–3.5 km deep, by which point passive tracers revealed that the convection was at least partly surface based. Soon after becoming surface based, both simulations produced severe surface winds, the strongest of which were associated with embedded low-level mesovortices and their attendant outflow surges and bowing segments. The origin of the simulated mesovortices was likely the downward tilting of system-generated horizontal vorticity (from baroclinity, but also possibly friction) within the simulated MCSs’ outflow, as has been argued in a number of previous studies. Taken altogether, it appears that severe nocturnal MCSs may often resemble their cold pool-driven, surface-based afternoon counterparts.
影响因子：
3.2
作者：
J. Marsham;S. Trier;T. Weckwerth;James W. Wilson
通讯作者：
J. Marsham;S. Trier;T. Weckwerth;James W. Wilson
PECAN期间中尺度对流系统对流前和对流后环境剖面的演变
影响因子：
3.2
作者：
Hitchcock, Stacey M.;Schumacher, Russ S.;Herman, Gregory R.;Coniglio, Michael C.;Parker, Matthew D.;Ziegler, Conrad L.
通讯作者：
Ziegler, Conrad L.
低水平湿度误差对 PECAN 期间观测到的 MCS 模型预测的影响
影响因子：
3.2
作者：
Peters, John M.;Nielsen, Erik R.;Parker, Matthew D.;Hitchcock, Stacey M.;Schumacher, Russ S.
通讯作者：
Schumacher, Russ S.