纬向风与赤道异常的行星波同步振荡及其谱分析

SPECTRAL ANALYSIS FOR THE LONG PERIOD OSCILLATIONS IN THE EIA AND ITS COINCIDENCE WITH THE ZONAL NEUTRAL WIND

本文利用最大熵谱分析方法处理了电离层赤道异常北峰Okinawa站的f_0F_2行星波周期的振荡.比较同一期间相近经度链上的南北半球观测到的低热层中性大气运动,发现较短周期的2—5日波,尤其是在南北半球的夏季期间(北半球7—8月前后,南半球1—2月前后),其纬向风与赤道异常振荡强弱及周期变化具有良好的同步对应性.对于较长周期的中性风振荡,只要其幅度相当大,也会在赤道异常的振荡中有所对应.从而提供证据说明中性风的行星波振荡是赤道异常的行星波振荡的驱动源.

The day-to-day variations of the f0F2 value in the EIA's north crest (Okinawa) are processed with the Maximum Entropy spectral analysis Method (MEM), and so the long ptriod oscillations of EIA are studied more deeply. The 'oscillations of the EIA and the neutral wind on two hemisphere, that were observed in the same time and nearby longitude chain, are compared. For short period wave (2-5 day), especially during the summer time of the two hemisphere (around Jul. and Aug. in the northern, Jan. and Feb. in the other), the variations of the strength and period in the EIA's and zonal neutral wind oscillations are in well agreement; for longer period wave, if the amplitude of the wind is rather large, there is also re-spondence in the EIA's variation. So it gives proof evidence to prove that the long period oscillation of the neutral wind is the driving source of the same oscillation in the EIA.