High-Resolution Doppler Lidar Observations of Transient Downslope Flows and Rotors
High-Resolution Doppler Lidar Observations of Transient Downslope Flows and Rotors
复制标题
瞬态下坡流和转子的高分辨率多普勒激光雷达观测
DOI：
10.1175/mwr-d-12-00260.1
复制
发表时间：
2013
影响因子：
3.2
通讯作者：
M. Weissmann
中科院分区：
文献类型：
--
作者：
C. Kühnlein;A. Dörnbrack;M. Weissmann
摘要本文对具有旋翼和内部水力跃变的下坡风暴的时间演变进行了前所未有的详细和时空覆盖观测。在2006年地形诱导旋翼试验（T-REX）第六次密集观测期间，利用相干多普勒激光雷达在南内华达山脉背风处进行了观测。本文分析并比较了两种具有代表性的流型。第一种情况显示了高动量空气脉冲向东传播，在前缘有一个内部液压跃变。瞬态内跳下游区域以湍流为特征，但未观察到相干转子循环。在第二种情况下，发生了野外活动中最强的风暴T-REX。观测到的这一事件的特征类似于转子的经典概念。总之，多普勒激光雷达对两个下坡流事件的观测揭示了一个比较。
AbstractThe authors present observations of the temporal evolution of downslope windstorms with rotors and internal hydraulic jumps of unprecedented detail and spatiotemporal coverage. The observations were carried out by means of a coherent Doppler lidar in the lee of the southern Sierra Nevada range during the sixth intensive observational period of the Terrain-induced Rotor Experiment (T-REX) in 2006. Two representative flow regimes are analyzed and juxtaposed in this paper. The first case shows pulses of high-momentum air that propagate eastward through the valley with an internal hydraulic jump on the leading edge. The region downstream of the transient internal hydraulic jump is characterized by turbulence but no coherent rotor circulation was observed. During the second case, the strongest windstorm of the field campaign T-REX occurred. The observed features of this event resemble the classical notion of a rotor. Altogether, the Doppler lidar observations of both downslope flow events reveal a comp...