Phase relationships between total electron content variations, Doppler velocity oscillations and geomagnetic pulsations
- National Central Univ., Chung-Li (Taiwan, Province of China)
- Utah State Univ., Logan, UT (United States)
The phase relationship between variations of ionospheric total electron content (TEC) and ground-level ULF geomagnetic pulsations has been examined for the advection and compression mechanisms. To determine the causal mechanism several earlier studies have examined the phase difference between oscillations of Doppler velocity in ionospherically reflected radio waves and simultaneous ULF geomagnetic pulsations. In most instances it was found that the phase relation varied from event to event. With the application of Euler`s formula this study shows that in low geomagnetic and midgeomagnetic latitudes the phase differences between variations of TEC and ULF pulsations in the northward component of the geomagnetic field due to the advection and compression mechanisms are 0{degrees} and 180{degrees}, respectively. The authors also found that TEC variations tend to lead ionospheric Doppler velocity oscillations by 90{degrees}. Furthermore, it is shown that the phase relationship between ionospheric Doppler velocity oscillations and ULF pulsations of the northward component of the geomagnetic field, caused by the advection and compression mechanisms, are functions of the scale length, frequency of ULF waves, and geomagnetic dip. 25 refs., 4 figs.
- OSTI ID:
- 166277
- Journal Information:
- Journal of Geophysical Research, Vol. 99, Issue A9; Other Information: PBD: 1 Sep 1994
- Country of Publication:
- United States
- Language:
- English
Similar Records
Field and thermal plasma observations of ULF pulsations during a magnetically disturbed interval
Seasonal and diurnal dependence of Pc 3-5 magnetic pulsation power at geomagnetically conjugate stations in the auroral zones