The chromospheric network extended to the transition region as the solar EUV network disperses at the coronal level. The EUV emission lines from the transition region give information about different atmospheric heights. The network properties have been obtained from the daily spectroscopic data from the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO) in two lines He i 584.5 A and O v 630 A. The synoptic changes in the line intensity, skewness of intensity distribution, mean contrast and network index with respect to the sunspot cycle were studied for a period of 11 years from 1996 to 2006. We have obtained the cross correlation of the monthly average of these quantities with the monthly sunspot number. The mean intensity and skewness of the two lines generally show a positive correlation with the sunspot cycle. The network contrast and network index of the He i shows a definite negative correlation with the sunspot cycle. The negative correlations shown by the He i line are unexpected which could be due to its anomalous behaviour. There are differences in the behaviour of the two lines regarding the time lag with the sunspot cycle and the magnitude of the correlation which is always higher for the He i line. The results have implications to the studies of solar irradiance, magnetic flux transfer and solar atmospheric dynamics.

中文翻译：

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太阳能 EUV 网络特性的时间变化

随着太阳 EUV 网络在日冕水平上分散，色球网络扩展到过渡区域。来自过渡区的 EUV 发射线提供有关不同大气高度的信息。网络属性是从太阳和日光层天文台 (SOHO) 上的日冕诊断光谱仪 (CDS) 的每日光谱数据中获得的，分两条线 He i 584.5 A 和 O v 630 A。线强度的天气变化，从1996年到2006年的11年期间，我们研究了太阳黑子周期的强度分布偏度、平均对比度和网络指数。我们得到了这些数量的月平均值与月黑子数的互相关。两条线的平均强度和偏度一般与太阳黑子周期呈正相关。He i 的网络对比度和网络指数与太阳黑子周期呈明显的负相关。He i 线显示的负相关是出乎意料的，这可能是由于其异常行为。关于与太阳黑子周期的时间滞后和相关性的大小，两条线的行为存在差异，He i 线总是更高。结果对太阳辐照度、磁通量转移和太阳大气动力学的研究具有重要意义。He i 线显示的负相关是出乎意料的，这可能是由于其异常行为。关于与太阳黑子周期的时间滞后和相关性的大小，两条线的行为存在差异，He i 线总是更高。结果对太阳辐照度、磁通量转移和太阳大气动力学的研究具有重要意义。He i 线显示的负相关是出乎意料的，这可能是由于其异常行为。关于与太阳黑子周期的时间滞后和相关性的大小，两条线的行为存在差异，He i 线总是更高。结果对太阳辐照度、磁通量转移和太阳大气动力学的研究具有重要意义。