2011-11-29 15:13:33Climategate 2.0 in Context - Solar Warming
Dana Nuccitelli

Pretty straightforward Climategate email post - nothing new really.

Climategate 2.0 in Context - Solar Warming

2011-11-29 15:43:47
Alex C


I think you're being very generous with the 2 W/m^2 figure upper bound on TSI, even since the Maunder Minimum we haven't seen such an increase.

This is something I've been wondering for a while too, and it doesn't really affect your article, but more recent TSI measurements as by TIM (and monitored by the University of Colardo here) have a lower baseline TSI, ~1360/1361 W/m^2, instead of 1365-1366.  They show the same variance, just seem to focus around different "averages," as it were.

Aside from that and a few quotation mark anomalies in the email snippet(s) (you may want to use ellipses where appropriate), and this typo:

"Moreover, since 1960, solar activity has declined slightly..."

as well as perhaps a reference for the response to that email (it's not in the one you linked to at foia2011, and the new emails were not sorted chronologically), it looks good to me.

2011-11-29 15:44:06
John Garrett
Typo: last paragraph, 2nd sentence: "decline" should be "declined" Great post.
2011-11-29 15:53:45
Dana Nuccitelli

Thanks guys.  Alex - the whole email chain is actually contained within that first link.  Just scroll on down.

Agreed that 2 W/m2 is pretty generous, though I may have seen some reconstructions with changes that large back when I was doing the "it's the Sun" advanced rebuttal.  But I think i'll drop the high end to 1.5 W/m2 to be more realistic.

2011-11-29 15:58:56
Alex C


I don't think that that was a response Dana.  The emails are set up so that the most recent message sent is on top, not on bottom.

2011-11-29 16:24:01
Dana Nuccitelli

Oh, well crap, that's inconvenient!  Good catch, thanks Alex.  I found the subsequent emails and will include a link and relevant quotes.

2011-11-30 21:18:52
Kevin C


This NOAA data:


which you can find all over the web in graphs like this:

puts the difference to the Maunder Minimum at 2.5 - 3W/m2.

That is rather larger than Vieira number, but it's widely quoted and from a reputable source (Lean).

Go to google images and search for 'solar irradiance' for more versions.

2011-12-01 01:56:56
Alex C


Kevin C,

To quote Lean 2000 (emph. mine):

"Most secure are the assumptions, based on analyses of contemporary solar activity cycles, that faculae and sunspots are dominant causes of spectral irradiance changes and that solar atmosphere models provide realistic represen tations of their wavelength dependent characteristics.  Least secure are assumptions about the nature of long-term irradiance variability, if it exists, and the applicability of Sun-like stars for estimating its amplitude. Thus, the reconstructions of the 11-year spectral irradiance cycles are relatively robust whereas the multi-decadal to centennial changes on which the cycles are superimposed are far more speculative. Significant effects not yet detected in the extant observations and absent from the modeled variations may substantially affect the reconstructions. An example is the potential influence on irradiance of speculated changes in solar diameter."

Lean incorporates sun-like stars for comparison, whereas following studies use cosmogenic isotopes, such as 14C and 44Ti.  There seems to be a consistent pattern, to, of later reconstructions resulting in dampened reconstructions of long term variability.

I'm not sure which is better than the other, but Lean et al themselves do note this issue with their method.