Seminars

Lecturer: Dr Yasuhide Hobara (IRF-K)
Date: 2005-02-17 10:00
Place: Aniara

Low latitude ionospheric turbulence observed by Aureol 3 and possible association with seismicity

Using PSD (Power Spectral Density) data on electron density and electric field variations observed on board Aureol-3 satellite at low-to-mid-latitude ionosphere we analyze a scale distribution of the ionospheric turbulence in a form k^-alpha, where k is the wave number and alpha is the fractal index. At first high-resolution data in the near-equator region for several orbits have been processed. In this case frequency range is from 6 Hz to 100 Hz (corresponding spatial scales from 80 m to 1.3 km), each power spectrum obeys a single power law fairly well, and the mean spectral indices are rather stable with alpha_N = 2.2±0.3, and alpha_E = 1.8±0.2 for the density and electric field, respectively. Then we produce statistical study of electric field bursts in the frequency range 10-100 Hz from low-time resolution data (filter bank envelope). These bursts concentrate aside of Equatorial Anomaly crest (geomagnetic latitude 30-40°) and their fractal indices vary in the interval alpha_E = 2.0 - 2.5. There is a weak systematic increase of their average intensity on about 3-4 dB during periods of seismic activity.

Created 2005-02-03 15:47:22 by Rick McGregor
Last changed 2005-02-03 15:47:22 by Rick McGregor