Does solar activity affect cloud cover?

Question

When the sun is active there is an increase in the suns magnetic field, electrically charged particles (solar wind), energy in the ultra violet spectrum can increase by 100%, and the energy in other spectrums will increase slightly. During The Little Ice Age, the sun entered a period of little or no solar activity called the Maunder Minimum. It was still shining brightly, but there were hardly any solar flares. The decreased solar wind allows more cosmic rays from outside the solar system to enter the atmosphere. Some scientists believe these cosmic rays help to seed clouds. We don't have any pictures from the Little Ice Age, but there are many paintings from artists of that era. Here are some links to landscape paintings, notice that the skies are overcast in most of the paintings:

http://www.bouman102.info/avercamp_hendrick.htm
http://www.postershop.ch/Brueghel-Piet/Brueghel-Piet-Jaeger-im-Schnee-2600217.html

http://www.masterworksartgallery.com/BRUEGHEL-Pieter-the-Younger/BRUEGHEL-Pieter-the-Younger-Winter-Landscape-with-a-Bird-trap.html

http://www.prints.co.nz/page/fine-art/PROD/Art_History/554

http://www.abcgallery.com/B/bruegel/pieter8.html

http://www.canvaz.com/gallery/2130.htm

http://www.masterworksartgallery.com/MEISSONIER-Jean-Louis-Ernest/MEISSONIER-Jean-Louis-Ernest-Napoleon-and-his-Staff.html

http://www.ibiblio.org/wm/paint/auth/david/st-bernard.jpg

The last 7 decades have been the highest solar activity in the past 8000 years.

http://www.space.com/scienceastronomy/sunspot_record_041027.html

Why would an artist create a dreary totally overcast sky? A blue sky is much prettier, especially with a white fluffy cloud hear and there. Many of the paintings contain blue pigments.

There are at least a dozen paintings of people playing on the ice. They all have dreary overcast skys. I would think the artists would want to convey a blue sky in at least one or two renditions of these joyful moments.

I've looked around at other paintings by Brueghel and he used blue in some of the others, especially in people's clothing and water. I also looked at Rembrandt's paintings from the same era. He didn't do a lot of landscapes, but the ones he did were also very cloudy or overcast. These paintings are made to look realistic and I believe they reflect the times. I know it is not proof, but it is not unreasonable to think that the paintings would resemble reality. There are several artists in my family and I know several more. When they paint something, they usually try to duplicate an object or a picture that they took.

The first 14 paintings are by Hendrick Avercamp, the next 4 ar Brueghel, the next two are Meissonier and I believe the last one is Jacques-Louis. You might look a little more carefully. As far as bringing it goes, the CO2 crap is weak.

Answer 1

It would be hard to believe that solar activity doesn't affect cloud cover. The two processes are definately related. I think the quantitative linkage and process may be debated but that there is a linkage hardly can be.

Answer 2

Svensmark debunked here.
http://environment.newscientist.com/channel/earth/climate-change/dn11651

Recalling my grandmothers wonderful freehand needlepoint, the most beautiful part for me are the skies. They are always fantastic transitions of color from a thousand multi-colored threads. Why did she put colors and clouds in her skies? I dunno, probably would be boring just to make a clear blue sky.

Be careful of causation. The clouds in paintings is an interesting idea but how can you attach the reason?

edit:
I'm only pointing this out because this is the point of your question, and I happen to have direct experience. Many of my grandmothers works are nothing but dreary overcast skies. The whole work is the sky in shades of gray and tiny bits of color interspersed, and just a little detail on the ground, in the background. Maybe she was depressed. Again, if you can't correlate the data, the conclusion is meaningless. "A blue sky is much prettier"? This is what is known as a subjective bias.

Answer 3

I dont' know that there is any direct connection between solar magnetic fields and cloud cover, however, if the sun's infrared is increasing then there would be more evaporation from the oceans, causing an increase in cloud cover, more storms, flooding etc.
There is some evidence that there is an increase in heat radiation from the Sun and/or possibly other sources - note that the polar caps on Mars are melting as well as here on Earth - obviously not because of anything humans are doing...

Answer 4

There are a number of fundamental problems with the GCR theory.

http://answers.yahoo.com/question/index;_ylt=AkCY_7Ayj6CgmztQ4MB3.n0jzKIX;_ylv=3?qid=20071030112550AA7AXSu

The biggest problem is that since 1951 as global warming has accelerated rapidly, there has been virtually no trend in GCR flux.

http://www.realclimate.org/images/TheChillingStars.jpg

It's entirely possible that the solar magnetic field indirectly affects cloud cover on Earth via GCRs, but there's not much evidence of this link, and there is much evidence that GCR flux is having little effect on the current warming even if there is such a link.

These landscape paintings are not evidence to the contrary. For one thing, they're each essentially equivalent to snapshots of one isolated location on the planet at one given time. For another, as other answerers have pointed out, there could be any number of reasons that many of these paintings depict overcast skies. Heck, we don't even know what season they were painted in.

*edit* Sorry, but I'll take hard scientific evidence over speculation as to why one artist tended to paint gray skies. Is Picasso's Blue Period a sign of global warming, too?

Answer 5

Good grief. Now, artistic taste is more important than the data?

Here's two scientific debunkings of the cosmic ray theory:

http://environment.newscientist.com/channel/earth/climate-change/dn11651
http://www.realclimate.org/index.php/archives/2006/10/taking-cosmic-rays-for-a-spin/#comment-20111

Note that scientists advancing this theory have been caught messing with the data:

Pattern of Strange Errors Plagues Solar Activity and Terrestrial Climate Data, Eos,Vol. 85, No. 39, 28 September 2004

Answer 6

Nice thought, but blue pigments, even those based on lapis lazuli, fade over time and become grayer.

http://www.bu.edu/phpbin/news-cms/news/?dept=1127&id=41091

Besides, lapis lazuli-based pigments were expensive and painting a blue sky would cost too much. Artists painted gray because it was cheaper.

Edit: Aside from the fact most of those scenes are from wintertime (unless all those people are walking on water and not ice skating), a lot of times a blue sky would not be in keeping with the emotion the artist wanted to convey. No painter would present Napoleon against a bright sunny sky, he was a warlord emperor, not some fuzzy bunny. A dark, thundercloud filled with ominous intent fit the mood. Similarly, all the shots of Napoleon's army marching into Russia would not be portrayed against a bright blue sky (even if it weren't prohibitively expensive to paint) because the outcome of his Russian campaign was a disaster. You can't show impending doom with bright sky. This is Art History 101, get a copy of Jansen's book History of Art and read up on interpretation of painting styles and on the history of pigments before you start making climatic inferences from renaissance and romantic era canvases.

Finally, one of those images does show a bright blue sky and it is the most pastoral of the lot, keeping with my analysis above.

Edit: I know you want to believe you've stumbled on evidence, but you haven't. There are a lot of problems with your "data set." First off, image 3 and image 5 are the same painting, although 5 only shows part of the scene. 5 has a much bluer tint, at least on my monitor, suggesting that the reproduction in 3 might have the color balance wrong. Second, without knowing anything about Brueghel it is difficult to determine any significance to your data set since so many paintings that are not Napoleon are by him. He may have been dirt-poor and couldn't afford blue pigment (which was expensive). He might have been a depressive and never saw anything as happy and cheerful.

Finally, in the link I provide above there is a picture of Madonna and child and in the window one can see a bright blue sky. Blue skies signified happiness and tranquility. Winters in the 1500's were not quiet reflective times, they were hardship after hardship to be suffered through hoping you didn't die of starvation, exposure, or disease before springtime. That Brueghel didn't paint blue skies is not a sign that there were none in his era, or at least not definitive evidence of more clouds.

This is another example of how you skeptics need to learn to bring it big time to these discussions. *You* need to do the research on this and determine if the lack of blue skies is indicative of something besides the base economics of blue pigments in the 1500's coupled with a general mood an artist may have wanted to convey. Selecting so many works from the same artist is not a good sampling.

Answer 7

Good links. It's hard to believe that there are still those who deny that the Sun plays any part in the Earths climate.