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极光弧是最常见的一种极光形态,其空间尺度大至数百千米,小至几十米.极光弧宽的研究对理解极光粒子加速机制及磁层-电离层中的跨尺度耦合具有重要意义.现有文献在计算极光弧图像中的弧宽时,多是只考虑了过天顶某条剖线上极光强度的变化,而忽略了极光弧的形态信息.文章从极光弧图像出发,利用计算机模式识别技术,自动识别出极光弧轮廓,在此基础上计算极光弧的宽度,统计弧宽分布规律.通过对2 0 0 3~2 0 0 5年北极黄河站越冬观测的2 5 2 0幅日侧全天空极光弧图像进行实验,并与Q i u等(2 0 1 3)结论进行对比,验证了文章方法的有效性.结果显示,黄河站全天空成像仪观测到的日侧极光弧空间尺度主要在1~1 0 0 k m量级,磁天顶附近±1 5°内极光弧宽的平均值为1 9.6 5 k m,并且随着天顶角远离磁天顶,极光弧宽增大.
Aurora arc is the most common form of aurora, its spatial scale up to hundreds of kilometers, as small as tens of meters.Aurora arc width to understand the acceleration mechanism of auroral particles and magnetic-ionospheric cross-scale coupling has The existing literature only considers the change of the auroral intensity on a section of the zenith while neglecting the morphological information of the auroral arc when calculating the arc width in the auroral arc image.According to the auroral arc image , The use of computer pattern recognition technology to automatically identify the aurora arc contour, on this basis, calculate the width of arc aurora, statistical arc width distribution.By the observation of the Arctic Yellow River Station overwintering from 2030 to 25 5 The experiment is carried out on 20 daily auroral arc images of the sky, and compared with the conclusion of Q iu et al (2001), which verifies the effectiveness of the proposed method. The results show that the observational day The spatial scale of auroral arc is mainly on the order of 1 ~ 100 km, and the average auroral arc width is ± 9.65 km within ± 15 ° near the magnetic zenith. With the zenith angle away from the magnetic zenith, the auroral arc width Increase.