From Bernd Herd, in honor of Nicola Scafetta, a gadget to show you how changes in sun spot number over the last couple of centuries doesn't explain very much.if you believe that the sunspot number is a good proxy for Total Solar Insolation aka TSI (bunnies can change the start date and the app updates each month)
Now some, including Eli might hope for a somewhat more recent take from the Sun Goddess or maybe even Leif Svalgaard. Before the getting too crazy about the app allow Eli to point out that one thing the Rabett has learned from Leif is that the sunspot number is at best an interesting proxy for solar irradiance, and at worst not such a good one. What is clear is that the old TSI reconstructions based on the Opinions, of course differ, but what is clear is that the variation since we have satellite observations has been minimal, nothing at all if we simply look at changes at the solar cycle minima, and less than 1 W/m2 from valley to peak.
That being said, over the Mauna Loa CO2 record, there is good agreement between the various solar reconstructions TSI do not correlate with the increase in temperature
Eli, I think that this is too simplistic. There is plenty of data that strongly hints at solar effect on longer time scales. See, e.g., The National Academies Press workshop report: http://www.nap.edu/catalog/13519/the-effects-of-solar-variability-on-earths-climate-a-workshop
ReplyDeleteOr this book: The Sun's Influence on Climate by Haigh and Cargill
These effects are not well understood, but there is pretty good proxy evidence. Most of these effects appear related to Grand Solar minima rather than piddling minima of recent years.
Of course the apparent existence of such effects doesn't say anything about the larger effect due to CO2.
ReplyDeleteI thought the only way that they could get a good fit using sunspot number was to integrate the sunspot number. Given that that would suggest some kind of multi-decade memory, it seems rather unphysical.
ReplyDeleteIIRC the correlation of GAT with Schwabe cycle is something like 0.2C peak to trough.
ReplyDeleteI think Leif Svalgaard's published version of the link Eli provides is Clette et al. (2014) Revisiting the sunspot number.
These effects are not well understood, but there is pretty good proxy evidence.
ReplyDeleteDepends on how far back you go, and your definition of 'pretty good' proxy evidence. Richard Telford has the scoop(s). Highly recommended.
Telford is great and it was Clette et (Leif being one of the ets)
ReplyDeleteOTOH the global T has moved quite a lot while the total solar has not, and the app makes that point.
OTOH the global T has moved quite a lot while the total solar has not, and the app makes that point.
ReplyDeleteIndeed it does, and Richard T's 'what evidence?' project isn't terribly encouraging for sun worshipers either.
et al. and Tsonis are cycling again:
ReplyDeletehttp://onlinelibrary.wiley.com/doi/10.1002/2015GL067325/abstract