Interactions between a Nocturnal MCS and the Stable Boundary Layer as Observed by an Airborne Compact Raman Lidar during PECAN
Interactions between a Nocturnal MCS and the Stable Boundary Layer as Observed by an Airborne Compact Raman Lidar during PECAN
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PECAN 期间机载紧凑型拉曼激光雷达观测到的夜间 MCS 与稳定边界层之间的相互作用
DOI：
10.1175/mwr-d-18-0388.1
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发表时间：
2019
影响因子：
3.2
通讯作者：
Jing Yang
中科院分区：
文献类型：
--
作者：
Guo Lin;B. Geerts;Zhien Wang;Coltin Grasmick;Xiaoqin Jing;Jing Yang
MCS的低层流出和流入内的小尺度变化可以支持或阻止MCS的高档增长和维持。然而，这些小规模的变化，特别是在热力学（温度和湿度），仍然知之甚少，由于缺乏详细的测量。部署在怀俄明州大学King Air飞机上的紧凑型拉曼激光雷达（CRL）以前所未有的垂直和沿轨分辨率沿着一系列成熟的夜间MCS的南部边缘直接采样温度和水汽廓线，这些MCS于2015年7月1日在夜间平原高架对流（PECAN）活动期间沿着锋面边界行进。在这里，说明了空中CRL记录MCS流入和流出电流之间的相互作用的能力。CRL揭示了较冷电流的明确边界。这被解释为锋面边界由对流引起的冷池，特别是下游MCS的流出边界锐化。在一个CRL样带中，锋面/外流边界出现了一个明显的两层结构的水分和气溶胶形成的潮湿稳定的边界层空气平流以上的边界。第二条样带，一小时后，揭示了一个单一的倾斜边界。在这两种情况下，潮湿的稳定分层的空气在边界上的放样有利于MCS的维护，通过增强升高CAPE和减少CIN。CRL数据的充分解决，以揭示开尔文-亥姆霍兹（KH）的波涛和垂直结构的流出边界，在这种情况下，表现为密度流，而不是一个波状孔。
Small-scale variations within the low-level outflow and inflow of an MCS can either support or deter the upscale growth and maintenance of the MCS. However, these small-scale variations, in particular in the thermodynamics (temperature and humidity), remain poorly understood, due to a lack of detailed measurements. The compact Raman lidar (CRL) deployed on the University of Wyoming King Air aircraft directly sampled temperature and water vapor profiles at unprecedented vertical and along-track resolutions along the southern margin of a series of mature nocturnal MCSs traveling along a frontal boundary on 1 July 2015 during the Plains Elevated Convection at Night (PECAN) campaign. Here, the capability of the airborne CRL to document interactions between the MCS inflow and outflow currents is illustrated. The CRL reveals the well-defined boundary of a cooler current. This is interpreted as the frontal boundary sharpened by convectively induced cold pools, in particular by the outflow boundary of the downstream MCS. In one CRL transect, the frontal/outflow boundary appeared as a distinct two-layer structure of moisture and aerosols formed by moist stable boundary layer air advected above the boundary. The second transect, one hour later, reveals a single sloping boundary. In both cases, the lofting of the moist stably stratified air over the boundary favors MCS maintenance, through enhanced elevated CAPE and reduced CIN. The CRL data are sufficiently resolved to reveal Kelvin–Helmholtz (KH) billows and the vertical structure of the outflow boundary, which in this case behaved as a density current rather than an undular bore.
影响因子：
8
作者：
K. Haghi;B. Geerts;H. Chipilski;Aaron Johnson;Samuel K. Degelia;David A. Imy;D. Parsons;R. Adams-Selin;D. Turner;Xuguang Wang
通讯作者：
K. Haghi;B. Geerts;H. Chipilski;Aaron Johnson;Samuel K. Degelia;David A. Imy;D. Parsons;R. Adams-Selin;D. Turner;Xuguang Wang
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
影响因子：
25.2
作者：
V. Wulfmeyer;R. Hardesty;D. Turner;A. Behrendt;M. Cadeddu;P. Di Girolamo;P. Schlüssel;J. van Baelen-J.-van-Ba
通讯作者：
V. Wulfmeyer;R. Hardesty;D. Turner;A. Behrendt;M. Cadeddu;P. Di Girolamo;P. Schlüssel;J. van Baelen-J.-van-Ba