Probing local wind and temperature structure using infrasound from Volcan Villarrica (Chile)
Probing local wind and temperature structure using infrasound from Volcan Villarrica (Chile)
复制标题
使用比亚里卡火山（智利）的次声探测当地的风和温度结构
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
S. Arrowsmith
中科院分区：
文献类型：
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作者：
Jeffrey B. Johnson;Jacob F. Anderson;O. Marcillo;S. Arrowsmith
[1]本文利用智利比利亚里卡火山产生的连续强次声波（107 W）反演了局地大气动力风场和温度场结构。2011年3月在峰顶（2826米）和西北偏北侧翼（825米处，距离808公里）部署的次声阵列用于跟踪次声传播时间和信号功率。我们模拟了一个垂直变化的温度和水平风的大气，并使用传播时间（范围从23到24秒）来反演水平慢度（2.75-2.94秒/公里）和平均有效声速（328-346米/秒）的NNW传播次声。在近端与远端阵列处记录的声功率的相应比率也是可变的（对于峰值0.33-1 Hz次声带，范围在0.15至1.5之间）。通过在均匀梯度大气中应用几何射线理论，这些“放大因子”由有效声速递减率（−15至+4 m/s/km）建模。在2826米处，西北偏北方向的预计风速范围为每秒-20米至每秒+20米，风梯度范围为每公里每秒-11米至每秒+10米，这是根据当地温度观测得出的有效声速剖面和绝热声速之间的差异推断出来的。这些风的感觉与无线电探空仪记录的区域气象观测结果基本一致。我们认为，次声探测可以提供有用的空间平均估计大气风结构，气象观测和火山羽流扩散建模的应用程序。
[1] We use the continuous and intense (∼107W) infrasound produced by Volcan Villarrica (Chile) to invert for the local dynamic wind and temperature structure of the atmosphere. Infrasound arrays deployed in March 2011 at the summit (2826 m) and on the NNW flank (∼8 km distant at 825 m) were used to track infrasound propagation times and signal power. We model an atmosphere with vertically varying temperature and horizontal winds and use propagation times (ranging from 23 to 24 s) to invert for horizontal slowness (2.75–2.94 s/km) and average effective sound speeds (328–346 m/s) for NNW propagating infrasound. The corresponding ratio of recorded acoustic power at proximal versus distal arrays was also variable (ranging between 0.15 to 1.5 for the peak 0.33–1 Hz infrasound band). Through application of geometrical ray theory in a uniform gradient atmosphere, these ‘amplification factors’ are modeled by effective sound speed lapse rates ranging from −15 to +4 m/s per km. NNW-projected wind speeds ranging from −20 m/s to +20 m/s at 2826 m and wind gradients ranging from −11 to +10 m/s per km are inferred from the difference between effective sound speed profiles and adiabatic sound speeds derived from local temperature observations. The sense of these winds is in general agreement with regional meteorological observations recorded with radiosondes. We suggest that infrasound probing can provide useful spatially averaged estimates of atmospheric wind structure that has application for both meteorological observation and volcanological plume dispersal modeling.
影响因子：
5.3
作者：
Dabrowa, A. L.;Green, D. N.;Phillips, J. C.
通讯作者：
Phillips, J. C.