极区F层不规则结构的分形模型

本文利用1986年9—12月期间17个电离层吸收事件的Riometer资料计算了电离层闪烁强度的Fourier谱和Bessel谱。求出了谱遵从的k~(-β)型函数的β值,1.8<β<2.5,平均为2.1;求出了不规则结构的漂移速度平均为129m/s。计算了各个事件的闪烁指数S_4<0.4。求出相位涨落空间谱,且指出其也遵从幂型函数k~(-α)规律。根据上述结果,本文提出极区F层不规则结构为分立的分形,不是分立的“斑块”。利用β值求出分形的分数维D=2.45。给出了不规则结构的近似分形模型。

A FRACTAL MODEL OF IONOSPHERIC IRREGULARITIES OF F-LAYER IN POLAR AREA

In this paper, the Fourier Spectrum and Bessel Spectrum of ionospheric scintillation intensity are calculated by Riometer data of 17 events of CNA happended during Sept. and Dec. in 1986. The value of power index of Fourier Spectrum, shift velocity of irregularity in ionosphere and scintillation index are found out. The Spatial Spectrum of phase fluctuation follows the power law are found out too. Depend on that the Fourier spectrum follows a power law, the power index is a negative number and the relation between the power index and the fractional demension, the fractional demetmon is about 2.45. It is shown that this fraction de-mension is also the fraction demension of the irregularity. It is the reason to be supposed in this paper that ionospheric irregularities are a separetory fractal and are not a separetory patch. And a Fractal model of ionospheric irregularity of F-layer in polar is also suggested.