The Distribution of Cell Sizes of the Solar Chromospheric Network
The Distribution of Cell Sizes of the Solar Chromospheric Network
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太阳色球层网络的像元大小分布
DOI：
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发表时间：
1997
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通讯作者：
A. Title
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作者：
H. Hagenaar;C. Schrijver;A. Title
本文研究了超颗粒网络的细胞模式。我们提出了一种算法，绘制一个不间断的两天序列的钙II K滤波图与1 nm的带通的表面填充细胞图案。60° × 40°的视场包含安静和增强的网络和谱斑。该算法使用了一个阈值无关的最速下降的方法在空间上平滑和时间平均的图像。我们确定的细胞面积的分布函数，并找到一个广泛的，不对称的光谱区域。如果将细胞面积归一化为单位平均值，则发现对于不同的空间平滑，该分布是不变的。正是这种不变性使我们相信我们已经确定了细胞面积的内在分布。外推的平均细胞大小为零空间平滑产生的特征细胞直径L = 13-18微米。这大约是一般引用的超颗粒长度尺度L = 32微米的一半，确定与自相关方法。特征细胞大小的差异反映了不同测量方法的应用：Simon & Leighton和其他人使用的自相关方法优先向相对较大的细胞加权。我们发现没有显着的依赖于当地的磁通量密度的细胞大小。
This paper studies the cellular pattern of the supergranular network. We present an algorithm to draw a surface-filling cell pattern on an uninterrupted two-day sequence of Ca II K filtergrams with a 1 nm bandpass. The 60° × 40° field of view contains both quiet and enhanced network and plages. The algorithm uses a threshold-independent method of steepest descent on spatially smoothed and time-averaged images. We determine the distribution function of cell areas and find a broad, asymmetric spectrum of areas. The distribution is found to be invariant for different spatial smoothings if the cell areas are normalized to a unit mean. It is this invariance that leads us to believe we have determined the intrinsic distribution of cell areas. Extrapolation of the average cell size to zero spatial smoothing yields a characteristic cell diameter of L = 13-18 Mm. This is roughly half the generally quoted supergranular length scale L ≈ 32 Mm as determined with autocorrelation methods. The difference in characteristic cell size reflects the application of a different measurement method: the autocorrelation method as used by Simon & Leighton and others is preferentially weighted towards relatively large cells. We find no significant dependence of cell size on local magnetic flux density.