论文标题
从地面光度观测值对太阳辐照度进行建模
Modelling solar irradiance from ground-based photometric observations
论文作者
论文摘要
自1978年以来，已经从空间监测了总太阳辐照度（TSI）。测量结果显示出与太阳周期相相的显着变化，并且比几天短的时间尺度波动。但是，测量是通过多个且通常相对短暂的任务完成的，这使得TSI的长期趋势高度不确定。尽管紫外线辐照度的变异性显然与太阳周期相结合，但可见范围内的变异性阶段已经进行了争议。在本文中，我们旨在了解自1996年以来TSI的长期趋势以及光谱可见部分的太阳辐照度变化的阶段。自1996年以来，我们使用Rome和San Fernando观测值的CA〜II〜K和连续体中的独立地面的全盘光度观测来计算TSI。我们遵循基于光度总和指数的经验SAN Fernando方法。 We find a weak declining trend in the TSI of -7.8$^{+4.9}_{-0.8}\times10^{-3}$ Wm$^{-2}$y$^{-1}$ between the 1996 and 2008 activity minima, while between 2008 and 2019 the reconstructed TSI shows no trend to a marginally decreasing (but statistically insignificant) trend of -0.1 $^{+0.25} _ { - 0.02} \ times10^{ - 3} $ wm $^{ - 2} $ y $^{ - 1} $。用于重建的参考TSI系列不会显着影响确定的趋势。蓝色连续体（409.2 nm）的变化相当平坦，而红色连续体（607.1 nm）的变化在反相中略有变化，尽管该结果对图像中静态太阳水平的准确评估非常敏感。这些结果为总太阳辐照度的长期变化提供了进一步的见解。可见的变化的幅度低于处理的不确定性，这阻止了对变化阶段的评估。
Total solar irradiance (TSI) has been monitored from space since 1978. The measurements show a prominent variability in phase with the solar cycle, as well as fluctuations on timescales shorter than a few days. However, the measurements were done by multiple and usually relatively short-lived missions making the possible long-term trend in the TSI highly uncertain. While the variability in the UV irradiance is clearly in-phase with the solar cycle, the phase of the variability in the visible range has been debated. In this paper, we aim at getting an insight into the long-term trend of TSI since 1996 and the phase of the solar irradiance variations in the visible part of the spectrum. We use independent ground-based full-disc photometric observations in Ca~II~K and continuum from the Rome and San Fernando observatories to compute the TSI since 1996. We follow the empirical San Fernando approach based on the photometric sum index. We find a weak declining trend in the TSI of -7.8$^{+4.9}_{-0.8}\times10^{-3}$ Wm$^{-2}$y$^{-1}$ between the 1996 and 2008 activity minima, while between 2008 and 2019 the reconstructed TSI shows no trend to a marginally decreasing (but statistically insignificant) trend of -0.1$^{+0.25}_{-0.02}\times10^{-3}$ Wm$^{-2}$y$^{-1}$. The reference TSI series used for the reconstruction does not significantly affect the determined trend. The variation in the blue continuum (409.2 nm) is rather flat, while the variation in the red continuum (607.1 nm) is marginally in anti-phase, although this result is extremely sensitive to the accurate assessment of the quiet Sun level in the images. These results provide further insights into the long-term variation of the total solar irradiance. The amplitude of the variations in the visible is below the uncertainties of the processing, which prevents an assessment of the phase of the variations.
