Fig.14. 361-day moving average of the integrated flux in the reconstruction and in UARS and SORCE SSI between a) 120 and 180 nm, b) 180 and 250 nm, c) 250 and 300 nm, and d) 300 and 410 nm. The UARS and SORCE time series are normalized to the reconstruction at the 1996 and 2008 solar cycle minima, respectively. The dashed lines indicate the uncertainty range of the reconstruction.
Reconstruction of total and spectral solar irradiance from 1974 to 2013 based on KPVT, SoHO/MDI, and SDO/HMI observations
K. L. Yeo, N. A. Krivova, S. K. Solanki, and K. H. Glassmeier
18 page PDF available on registration with Astronomy & Astrophysics
http://dx.doi.org/10.1051/0004-6361/201423628
ABSTRACT
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Context. Total and spectral solar irradiance are key parameters in the assessment of solar influence on changes in the Earth’s climate.
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Aims. We present a reconstruction of daily solar irradiance obtained using the SATIRE-S model spanning 1974 to 2013 based on full-disc observations from the KPVT, SoHO/MDI, and SDO/HMI.
- Methods. SATIRE-S ascribes variation in solar irradiance on timescales greater than a day to photospheric magnetism. The solar spectrum is reconstructed from the apparent surface coverage of bright magnetic features and sunspots in the daily data using the modelled intensity spectra of these magnetic structures. We cross-calibrated the various data sets, harmonizing the model input so as to yield a single consistent time series as the output.
- Results. The model replicates 92% (R 2 = 0.916) of the variability in the PMOD TSI composite including the secular decline between the 1996 and 2008 solar cycle minima. The model also reproduces most of the variability in observed Lyman-a irradiance and the MgII index. The ultraviolet solar irradiance measurements from the UARS and SORCE missions are mutually consistent up to about 180 nm before they start to exhibit discrepant rotational and cyclical variability, indicative of unresolved instrumental effects. As a result, the agreement between model and measurement, while relatively good below 180 nm, starts to deteriorate above this wavelength. As with earlier similar investigations, the reconstruction cannot reproduce the overall trends in SORCE/SIM SSI. We argue, from the lack of clear solar cycle modulation in the SIM record and the inconsistency between the total flux recorded by the instrument and TSI, that unaccounted instrumental trends are present.
- Conclusions. The daily solar irradiance time series is consistent with observations from multiple sources, demonstrating its validity and utility for climate models. It also provides further evidence that photospheric magnetism is the prime driver of variation in solar irradiance on timescales greater than a day.
This seems a comprehensive work trying to make sense of a bit of a mess from a hotch-potch of satellite data.
Post by Tim
Tallbloke's Talkshop 
The problem here is UV variability. Depth of absorption matters, not just for OHC in the diurnal overturning layer, but deeper as well where longer term accumulation and discharge can occur. It is the higher frequencies that vary most and also those frequencies that penetrate deepest into the oceans.
This study is admitting inaccuracy in higher frequencies, yet still claims “The daily solar irradiance time series is consistent with observations from multiple sources, demonstrating its validity and utility for climate models”
The other problem is there is no consistency between studies, each study showing differences.
Does this mean that solar irradiance AND heliospheric magnetic fields decline at the same time, a less heating, more cloud positive interaction that would counter the solar-irradiance-does-nothing claim.
I realize this is not about system-wide magnetic field issues. I’m just speculating two steps forward.
Konrad;
Wot? “The ultraviolet solar irradiance measurements from the UARS and SORCE missions are mutually consistent up to about 180 nm before they start to exhibit discrepant rotational and cyclical variability, indicative of unresolved instrumental effects. As a result, the agreement between model and measurement, while relatively good below 180 nm, starts to deteriorate above this wavelength.” Higher wavelength = lower frequency. “below 180 nm” is higher UV frequency.
Brian,
Figure 14 appears to show inconsistency occurring between 180 nm and 410 nm.