Imaging Doppler interferometry and the measurement of atmospheric turbulence
Imaging Doppler interferometry and the measurement of atmospheric turbulence
复制标题
成像多普勒干涉测量和大气湍流测量
DOI：
10.1029/97rs00089
复制
发表时间：
1997
期刊：
影响因子：
1.6
通讯作者：
J. Brosnahan
中科院分区：
文献类型：
--
作者：
R. Roper;J. Brosnahan
在1989年的阿雷西博大气动力学倡议期间，由成像多普勒干涉仪（IDI）3.175 MHz雷达拍摄的数据被解释为湍流参数。本文利用1989年4月10日1200- 1416 AST区间距天顶2°范围内散射体的均方根随机速度，用两种公式计算湍流能量的耗散率，一种是基于IDI技术识别的间歇性散射体的寿命估计（~ 100 s），另一种是基于湍流结构函数。这两种方法得出的湍流能量耗散率的上限值为0.01-0.06 W kg−1，在72 - 90 km范围内随高度增加而增加。湍流的能量承载涡尺度（忽略浮力）随高度变化，最小值在75 km（200 m），最大值在90 km（400 m）。浮力的影响进行了详细讨论，浮力，或外部规模，被发现从300米，75公里，最大900米，90公里。Kolmogorov微尺度，或内尺度，被发现从72公里处的1米增加到93公里处的10米。垂直涡流扩散系数的估计也作出了，所获得的值被证明是高度依赖于计算的假设。
Data taken by an imaging Doppler interferometer (IDI) 3.175‐MHz radar during the Arecibo Initiative on Dynamics of the Atmosphere in 1989 is interpreted in terms of turbulence parameters. The rms random velocity determined from scatterers within 2° of the zenith for the interval 1200–1416AST on April 10, 1989, is used to calculate the rate of dissipation of turbulent energy using two formulations, one based on an estimate of the lifetime (∼100 s) of the intermittent scatterers identified by the IDI technique, and another based on the turbulent structure function. Both techniques yield upper limit values of 0.01–0.06 W kg−1 for the rate of dissipation of turbulent energy, increasing with height over the range from 72 to 90 km. The energy‐bearing eddy scale of turbulence, neglecting buoyancy, is found to vary with height, being a minimum at 75 km (200 m) and a maximum at 90 km (400 m). The effects of buoyancy are discussed in detail, and the buoyancy, or outer scale, is found to vary from 300 m at 75 km to a maximum of 900 m at 90 km. The Kolmogorov microscale, or inner scale, is found to increase from 1 m at 72 km to 10 m at 93 km. Estimates of the vertical eddy diffusion coefficient are also made, and the values obtained are shown to be highly dependent on the assumptions underlying the calculations.