Large-Scale Waves in the Thermosphere Observed by the AE-C Satellite
Large-Scale Waves in the Thermosphere Observed by the AE-C Satellite
复制标题
AE-C卫星观测到的热层中的大尺度波浪
DOI：
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发表时间：
1984
影响因子：
8.2
通讯作者：
F. Huang
中科院分区：
文献类型：
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作者：
S. Gross;C. Reber;F. Huang
分析了大气探测器C（AE-C）的数据，以研究在大约260公里高度的热层中的波动扰动。这些数据是在1975年1月20日的一次轨道上测量的。所示例子是卫星AE-C和AE-E的许多其他轨道的典型例子。四个地球物理参数进行了分析：氮和氧的密度，电子密度和离子温度，由三种不同的仪器测量。通过将数据归一化为平均值并提取其趋势来处理数据。它们的波动是通过将归一化的去趋势数据通过高通滤波器获得的。强周期性是明显的，持续整个记录，无论过滤器的截止频率。通过计算互相关函数来比较波动。使用MEM和FFT程序获得光谱。它表明，第一次，离子的变化和中性变化之间的关系是一致的，在全球范围内的尺度大小。从平面波模拟研究和全球距离上的持续周期性还可以推断，热层中存在一种准定常波结构，这种结构可能会慢慢消散，并由极光区源再生。大规模的结构被发现在所有四个参数的水平尺度大小范围从约400至约4000公里。所有参数的光谱包含由波动周期确认的波长处的峰，并且随着波长的减小而减小，具有幂律类型的变化。
Atmosphere Explorer C (AE-C) data are analyzed to study wavelike perturbations in the thermosphere at an altitude of about 260 km. The data were measured during one orbit on January 20, 1975. The examples shown are typical of many other orbits of both satellites AE-C and AE-E. Four geophysical parameters are analyzed: nitrogen and oxygen densities, electron density, and ion temperature, as measured by three different instruments. The data are processed by normalizing them to their average values and extracting their trends. Their fluctuations are obtained by passing the normalized detrended data through a high-pass filter. Strong periodicities are apparent that persist throughout the records, regardless of filter cutoff frequency. Fluctuations are compared by computing cross correlation functions. Spectra are obtained using the MEM and FFT procedures. It is demonstrated, for the first time, that relationships between ion variations and neutral variations are coherent over a wide range of scale sizes over global distances. It is also inferred from plane wave modeling studies and from the persistent periodicities over global distances that a quasi-stationary wave structure is present in the thermosphere that may slowly dissipate and be regenerated by auroral region sources. Large-scale structures are found in all four parameters with horizontal scale sizes ranging from about 400 to about 4000 km. The spectra for all parameters contain peaks at wavelength that are confirmed by the periods of the fluctuations, and decrease with decreasing wavelength with a power law type of variation.