Estimation of turbulence parameters in the lower atmosphere from MST radar observations
Estimation of turbulence parameters in the lower atmosphere from MST radar observations
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根据 MST 雷达观测估计低层大气中的湍流参数
DOI：
10.1256/qj.03.86
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
B. V. K. Murthy
中科院分区：
文献类型：
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作者：
K. Satheesan;B. V. K. Murthy
利用Gadanki（13.5° N，79.2 °E）对流层和平流层下部的中间层-平流层-对流层（MST）雷达观测资料，研究了惯性子区垂直风的时间谱性质。结果表明，谱的斜率依赖于背景水平风速。湍流动能耗散率ε已使用MST雷达观测通过（i）多普勒谱宽法、（ii）后向散射信号功率法和（iii）速度方差法估算。对这三种方法估算的对流层和平流层低层的ε进行了详细的比较。结果表明，在对流层水平风背景较高的地区，方差法与其它两种方法所得的ε值差异很大。在平流层低层背景水平风条件下，三种方法所得的ε值各不相同。结果表明，对流层高背景水平风区的湍流是各向异性的，方差法和其它两种方法对ε的估计值之间的差异是由于各向异性湍流的存在。版权所有© 2004年皇家气象学会
Using the Mesosphere‐Stratosphere‐Troposphere (MST) radar observations at Gadanki (13.5°N,79.2°E) in the troposphere and lower stratosphere, the nature of the temporal spectrum of the vertical wind in the inertial sub‐range is investigated. It is found that the slope of the spectrum depends upon the background horizontal wind speed. The turbulent‐kinetic‐energy dissipation rate ε has been estimated using the MST radar observations by (i) the Doppler spectral‐width method, (ii) the backscatter signal‐power method, and (iii) the velocity‐variance method. A detailed comparison of the ε in the troposphere and lower stratosphere estimated by the three methods has been carried out. It is found that ε by the variance method differs from that by the other two methods very significantly in the troposphere where the background horizontal wind is high. In the lower stratosphere with low background horizontal wind, ε from the three methods is different in each case. It appears that turbulence in the regions of high background horizontal wind in the troposphere is anisotropic and the differences between the estimates of ε by the variance method and the other two methods are attributed to the presence of anisotropic turbulence. Copyright © 2004 Royal Meteorological Society