Latitudinal distribution of soft X-ray flares and dispairty in butterfly diagram
Latitudinal distribution of soft X-ray flares and dispairty in butterfly diagram
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DOI：
10.1007/s10509-014-2148-8
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发表时间：
2015-03
影响因子：
1.9
通讯作者：
K. Pandey;G. Yellaiah;K. M. Hiremath
中科院分区：
文献类型：
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作者：
K. Pandey;G. Yellaiah;K. M. Hiremath
本文对1976-2008年期间由地球同步业务环境卫星（GOES）观测到的约63000次软X射线耀斑（≥C级）进行了统计分析。自第21个周期以来，软X射线（SXR）耀斑的发生率呈下降趋势。第21周的分布格局显示耀斑活动的半球优势由北方向南半球转移，并在第22和23周期间保持在那里。在这三个周期中，南半球0-100、21- 300纬度带和北方半球31- 400纬度带的强度较大。两半球11- 200纬度带最强。在北方半球，相邻纬度间的相关系数从赤道向极方向逐渐增大，而在南半球，从极方向向赤道方向逐渐增大。拟合日耀斑计数的不对称时间序列的回归线的斜率是负的，在所有三个周期的不同类别的耀斑。用正弦函数拟合的年不对称曲线周期在5.6 ~ 11年之间，并与耀斑强度有关。用蝶翼图拟合的曲线从一阶到二阶多项式的变化表明，耀斑活动的纬向迁移随周期的不同而不同，也随北方到南半球而不同。不同耀斑级蝶翼斜率的变化表明耀斑活动的不均匀迁移。
We present statistical analysis of about 63000 soft X-ray flare (class≥C) observed by geostationary operational environmental satellite (GOES) during the period 1976–2008. Class wise occurrence of soft X-ray (SXR) flare is in declining trend since cycle 21. The distribution pattern of cycle 21 shows the transit of hemispheric dominance of flare activity from northern to southern hemisphere and remains there during cycle 22 and 23. During the three cycles, 0–100, 21–300latitude belts in southern hemisphere (SH) and 31–400latitude belt in northern hemisphere (NH) are mightier. The 11–200latitude belt of both hemisphere is mightiest. Correlation coefficient between consecutive latitude appears to be increasing from equator to poleward in northern hemisphere whereas pole to equatorward in southern hemisphere. Slope of the regression line fitted with asymmetry time series of daily flare counts is negative in all three cycles for different classes of flares. The yearly asymmetry curve fitted by a sinusoidal function varies from 5.6 to 11 years period and depends upon the intensity of flare. Variation, of curve fitted with wings of butterfly diagram, from first to second order polynomial suggests that latitudinal migration of flare activity varies from cycle to cycle, northern to southern hemisphere. The variation in slope of the butterfly wing of different flare class indicates the non uniform migration of flare activity.