Reconstruction of total solar irradiance 1974-2009
Reconstruction of total solar irradiance 1974-2009
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DOI：
10.1051/0004-6361/201118702
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发表时间：
2012-05-01
影响因子：
6.5
通讯作者：
Jaffe, A. H.
中科院分区：
文献类型：
--
作者：
Ball, W. T.;Unruh, Y. C.;Jaffe, A. H.
上下文。研究太阳总辐照度（TSI）的变化对于了解太阳如何影响地球气候是很重要的。现在可以获得三个完整太阳周期的全圆盘连续图像和磁图。我们通过建立一个一致的TSI模型数据集来研究如何将模拟TSI与直接观测进行比较。该模型仅基于光球磁通量的变化，然后可以在旋转、周期和长期时间尺度上进行测试。我们在SATIRE-S模型中使用Kitt Peak和SoHO/MDI连续图像和磁图来重建周期21-23的TSI。为了最大限度地独立于TSI复合材料，SORCE/TIM TSI数据用于固定模型的一个自由参数。我们比较和结合模型的独立数据源，以估计重建的不确定性，并防止任何额外的自由参数进入模型。尽管在太阳自转的时间尺度上，IRMB复合数据提供了更好的一致性，但重建结果支持PMOD复合数据是TSI观测的最佳历史记录。此外，该模型能够解释1978年至2009年PMOD组合中92%的TSI变化，并且在周期23期间超过96%。在第23个周期极小值之间，重建结果也显示出周期间的长期下降0.20(-0.09)(+0.12)W m(-2)，与PMOD综合结果一致。SATIRE-S能够重建自1978年以来31年间一天或更长时间尺度上的TSI观测。这是一个强有力的证据，表明光球磁通量的变化是过去三个太阳活动周期中几乎所有太阳辐照度变化的原因。
Context. The study of variations in total solar irradiance (TSI) is important for understanding how the Sun affects the Earth's climate.Aims. Full-disk continuum images and magnetograms are now available for three full solar cycles. We investigate how modelled TSI compares with direct observations by building a consistent modelled TSI dataset. The model, based only on changes in the photospheric magnetic flux can then be tested on rotational, cyclical and secular timescales.Methods. We use Kitt Peak and SoHO/MDI continuum images and magnetograms in the SATIRE-S model to reconstruct TSI over cycles 21-23. To maximise independence from TSI composites, SORCE/TIM TSI data are used to fix the one free parameter of the model. We compare and combine the separate data sources for the model to estimate an uncertainty on the reconstruction and prevent any additional free parameters entering the model.Results. The reconstruction supports the PMOD composite as being the best historical record of TSI observations, although on timescales of the solar rotation the IRMB composite provides somewhat better agreement. Further to this, the model is able to account for 92% of TSI variations from 1978 to 2009 in the PMOD composite and over 96% during cycle 23. The reconstruction also displays an inter-cycle, secular decline of 0.20(-0.09)(+0.12) W m(-2) between cycle 23 minima, in agreement with the PMOD composite.Conclusions. SATIRE-S is able to recreate TSI observations on all timescales of a day and longer over 31 years from 1978. This is strong evidence that changes in photospheric magnetic flux alone are responsible for almost all solar irradiance variations over the last three solar cycles.