Home > solar > Spectral irradiance phasing, TSI does not fit common assumptions, earth is affected

Spectral irradiance phasing, TSI does not fit common assumptions, earth is affected


Figure 1 from paper, for extensive caption see paper or copied below.

Recent variability of the solar spectral irradiance and its impact on climate modelling

I. Ermolli1, K. Matthes2, T. Dudok de Wit3, N. A. Krivova4, K. Tourpali5, M. Weber6, Y. C. Unruh7, L. Gray8, U. Langematz9, P. Pilewskie10, E. Rozanov11,12, W. Schmutz11, A. Shapiro11, S. K. Solanki 4,13, and T. N. Woods10

  1. INAF, Osservatorio Astronomico di Roma, Monte Porzio Catone, Italy
  2. GEOMAR I Helmholtz-Zentrum für Ozeanforschung Kiel, Kiel, Germany
  3. LPC2E, CNRS and University of Orléans, Orléans, France
  4. Max-Planck-Institut für Sonnensystemforschung, 37191 Katlenburg-Lindau, Germany
  5. Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki, Greece
  6. Institut für Umweltphysik, Universität Bremen FB1, Bremen, Germany
  7. Astrophysics Group, Blackett Laboratory, Imperial College London, SW7 2AZ, UK
  8. Centre for Atmospheric Sciences, Dept. of Atmospheric, Oceanic and Planetary Physics, University of Oxford, UK
  9. Institut für Meteorologie, Freie Universität Berlin, Berlin, Germany
  10. University of Colorado, Laboratory for Atmospheric and Space Physics, Boulder, CO, USA
  11. Physikalisch-Meteorologisches Observatorium, World Radiation Center, Davos Dorf, Switzerland
  12. IAC ETH, Zurich, Switzerland
  13. School of Space Research, Kyung Hee University, Yongin, Gyeonggi 46-701, Republic of Korea

Correspondence to: I. Ermolli
Received: 29 July 2012 – Published in Atmos. Chem. Phys. Discuss.: 19 September 2012
Revised: 6 March 2013 – Accepted: 13 March 2013 – Published: 17 April 2013

Atmos. Chem. Phys., 13, 3945–3977, 2013
© Author(s) 2013. CC Attribution 3.0 License.

First few lines of a long abstract from a 33 page paper.

Abstract. The lack of long and reliable time series of solar spectral irradiance (SSI) measurements makes an accurate quantification of solar contributions to recent climate change difficult. Whereas earlier SSI observations and models provided a qualitatively consistent picture of the SSI variability, recent measurements by the SORCE (SOlar Radiation and Climate Experiment) satellite suggest a significantly stronger variability in the ultraviolet (UV) spectral range and changes in the visible and near-infrared (NIR) bands in anti-phase with the solar cycle. …

Caption to head graphic figure 1

Fig. 1. The solar spectral irradiance as inferred from SORCE and TIMED observations only, from 22 April 2004 till 23 July 2010.
(A) shows the average solar spectral irradiance for that period. A black-body model has been used to extend the SSI for wave lengths beyond 1580nm. (B) displays the characteristic altitude of absorption in the Earth’s atmosphere for each wavelength, defined as the altitude at which the optical depth equals one. (C) shows the relative variability (peak to peak/average) for solar cycle variations inferred from measurements obtained between 22 April 2004 and 23 July 2010. Spectral regions, where the variability is in phase with the solar cycle (represented by, e.g. the sunspot number or the TSI) are marked in red, while blue denotes ranges where the variability measured by SORCE is out-of-phase with the solar cycle. These phases, as well as the magnitude of the variability in the UV, are not all reproduced by models and other observations (see Sect. 3 as well as Figs. 2, 7 and 8), and thus should be considered with care. (D) shows the absolute variability, which peaks strongly in the near-UV.

This paper tends to throw a hawk into a flock of roosting pigeons over their nice neat concept of solar TSI being a simple radiative energy source, instead of a complex body linking in many more ways with earth. This paper does not touch magnetic, which is a critical linkage.

A known confounding effect is the contradiction of sunspot darkening reducing irradiance at the same time as an increase of harder radiation from the periphery.

As an intense hot body there are still unknowns about the reason for the particular irradiance shape, Wien law, UV catastrophe and so on yet there are many temperatures involved, the sun is approximated. We can only view the sun through a fog anyway, near space rather than deep space.

The poor data is covered, instrumentation which unfortunately was not as good as hoped. This relates to this Daedal Earth (and Tallblokes Talkshop) article https://daedalearth.wordpress.com/2013/06/14/nist-and-tsi-unknown-systematic-bias/

Arctic oddness and Ozone

Quite some time ago I pointed out elsewhere there seemed to be an excess of shortwave solar emission where a minor spat arose with a certain other party who hotly disagreed, insisting this was a satellite instrument malfunction (disagreement never resolved). I was pointing at the slight Arctic ice loss correlating with the excess irradiance.

Since then the sun has continued to confound.

This paper mentions solar UV and a terrestrial Ozone reaction in northern regions, Ozone forward radiation having little understood effect on the lower altitude systems, it does also reach ground level.


Figure from paper suggests northern solar affect. Did they considered a magnetic connection? Interesting nonetheless.

For an historic context…

From Smithsonian Miscellaneous Collections, Volume 65, Number 3, Anders Angstrom writes in late 1913 (K Angstrom is his father)

In this “Study of the Radiation of the Atmosphere,” I have at tempted an investigation of the influence of various factors humidity, temperature, haze, clouds — upon the radiation of the atmosphere. The results of these investigations are briefly summarized at
the beginning of the paper.
It may be of advantage here to state in a few words in what respects this study must be regarded as incomplete and in need of further extended investigations. In the first place, it will be noticed that my observations have been limited to a particular time of year; the observations in Algeria and in California have all been made during the periods July-August of the years 1912 and 1913.
Now the investigations, as yet unpublished, carried on at the Physical Institute of Upsala, indicate that the amount of ozone contained in the atmosphere is larger in winter time than in summer time. Further, it has been shown by K. Angstrom ‘ that the ozone has two strong absorption bands, the one at A = 4.8µ, the other at A = 9. 1 to 10µ, of which the latter especially is situated in a region of the spectrum where the radiation of a black body of the temperature of the atmosphere ought to have its maximum of radiation. Then it is obvious that the radiation of the atmosphere must be dependent also upon the quantity of ozone present. Spectroscopic investigations indicate that in the summer time the ozone present in the air is practically nil; it is therefore not liable to have introduced any complications into the results discussed in this paper. But in the winter the quantity of ozone is often considerable, and it is not impossible that the variations of the effective radiation in the winter may be partly due to variations in the quantity of ozone in the upper air layers. The consequence of the higher radiating power of the atmosphere, due to the presence of ozone, must be that the effective radiation ought to be found to be less in the winter than is to be expected from the observations discussed in this paper.
Another point where it is desirable that the observations of the ” nocturnal radiation”should be extended, is in regard to conditions under which the quantity of water in the air is very small.

There were three Angstrom: Anders, father of Knut, father of Anders, all phycists, all notable. The first is honoured by the unit Angstrom, the second as a radiation instrument designer and builder, the third using the instruments to good effect and helping build through to today. TSI instruments? Effectively the same as Knut designed around 1900 [1].

The last, quoted above which is part of a large tale I have yet to reveal, can with care (because of WMO spin) be background read here Interview With Dr Anders K. Ångström

1. From ISS, OVIM (Solar Variability and Irradiance Monitor) ref

SOVIM1, developed at IRMB, contains one absolute radiometer DIARAD (Dual Irradiance Absolute Radiometer). DIRAD is composed of two cylindrical cavities coated inside with diffuse black and mounted next to each other on the same heat sink. The flat bottom of the cavities are in fact heat flux transducers on which heating elements have been mounted. Both cavities see the same thermal environment through accurately know circular apertures. The operation is based on electrical substitution. The difference of the electrical power fed to the active channel when its shutter is open (exposed to the sun) and when it is closed is proportional to the incident solar irradiance.

Obfuscating, not a lot different from a human operating an electrical servo loop by hand before electronics had been invented to get measures of solar radiation, add wrapping the thing in a cavity. Concept is balance, errors cancel: this is the same as that, therefore…

Now’t new under the sun

Categories: solar

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