Chunchuzov Igor, Kulichkov Sergey, Perepelkin Vitaly, Ziemann Astrid, Arnold Klaus, Kniffka Anke
Obukhov Institute of Atmospheric Physics, Moscow, Russia.
J Acoust Soc Am. 2009 Feb;125(2):651-63. doi: 10.1121/1.3056477.
The results of acoustic tomographic monitoring of the coherent structures in the lower atmosphere and the effects of these structures on acoustic signal parameters are analyzed in the present study. From the measurements of acoustic travel time fluctuations (periods 1 min-1 h) with distant receivers, the temporal fluctuations of the effective sound speed and wind speed are retrieved along different ray paths connecting an acoustic pulse source and several receivers. By using a coherence analysis of the fluctuations near spatially distanced ray turning points, the internal wave-associated fluctuations are filtered and their spatial characteristics (coherences, horizontal phase velocities, and spatial scales) are estimated. The capability of acoustic tomography in estimating wind shear near ground is shown. A possible mechanism describing the temporal modulation of the near-ground wind field by ducted internal waves in the troposphere is proposed.
本研究分析了低层大气中相干结构的声学层析监测结果以及这些结构对声学信号参数的影响。通过使用远距离接收器测量声学传播时间波动（周期为1分钟至1小时），沿着连接声脉冲源和多个接收器的不同射线路径反演有效声速和风速的时间波动。通过对空间上相距一定距离的射线转折点附近波动进行相干分析，滤除与内波相关的波动，并估计其空间特征（相干性、水平相速度和空间尺度）。展示了声学层析成像在估算近地面风切变方面的能力。提出了一种可能的机制，用于描述对流层中管道内波对近地面风场的时间调制。
