 |
Posted on 01/25/2007 4:40:59 PM PST by blam
Sun's fickle heart may leave us cold
25 January 2007
From New Scientist Print Edition.Stuart Clark
There's a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years - exactly the same period as between ice ages on Earth. So says a physicist who has created a computer model of our star's core.
Robert Ehrlich of George Mason University in Fairfax, Virginia, modelled the effect of temperature fluctuations in the sun's interior. According to the standard view, the temperature of the sun's core is held constant by the opposing pressures of gravity and nuclear fusion. However, Ehrlich believed that slight variations should be possible.
He took as his starting point the work of Attila Grandpierre of the Konkoly Observatory of the Hungarian Academy of Sciences. In 2005, Grandpierre and a collaborator, Gábor Ágoston, calculated that magnetic fields in the sun's core could produce small instabilities in the solar plasma. These instabilities would induce localised oscillations in temperature.
Ehrlich's model shows that whilst most of these oscillations cancel each other out, some reinforce one another and become long-lived temperature variations. The favoured frequencies allow the sun's core temperature to oscillate around its average temperature of 13.6 million kelvin in cycles lasting either 100,000 or 41,000 years. Ehrlich says that random interactions within the sun's magnetic field could flip the fluctuations from one cycle length to the other.
These two timescales are instantly recognisable to anyone familiar with Earth's ice ages: for the past million years, ice ages have occurred roughly every 100,000 years. Before that, they occurred roughly every 41,000 years.
Most scientists believe that the ice ages are the result of subtle changes in Earth's orbit, known as the Milankovitch cycles.
(Excerpt) Read more at environment.newscientist.com ...
btt
If he is not careful, he will bite off his tongue.
Make that two handles I love, marktwain. I have "Fallen Angels", on the bookshelf, original hardback from '91. In postscript authors note that solar neutrino emmissions are lower than expected and "astronomers tell us that we are going into a new period of minimum solar activity".
Seems I read we had detected an increase in surface temp not only on Mars, where we actually have stuff, but the moon Triton and the (planet?) Pluto more recently. Pluto, despite moving into aphelion, showed an increase of over 3 degrees F during a recent eclipse of a star.
Memo to Algore: if you don't get the Plutonians to sign Kyoto, the nitrogen snow might vaporize, creating hellacious storms and blowing over their igloos.
If you look at both the blue and red traces, you will see that CO2 is an effect of temperature changes, not a cause. Sometime after the temperature starts rising, CO2 starts rising. Sometime after the temperature falls, CO2 falls.
BTTT
Shoot, you must have better eyes than me. I'll have to go look at my original frame of that one!
| |
The ring of fire is escaping! She needs an exorcism bad!
I did one way back with red glowing eyes, another one lost in the files, lol
Red Pulsars
Her face is a thirsty canvas
Always needing more paint
Yes, for her age she does not look good.
So where are we in the cycle?
I've noticed that. And now this morning I wake up and it's frigid. It's 11 degrees and snowing here.
Sorry, just one.
Please FREEPMAIL me if you want on or off the
"Gods, Graves, Glyphs" PING list or GGG weekly digest
-- Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
Gods, Graves, Glyphs (alpha order)
the Earth is six thousand years old.
Higher temps would mean more plant life activity producing more carbon dioxide.
"I wouldn't show that particular graph around here if I were you.
After all if you ignore the blue line and focus on the red (the CO2 ppmv data) then it appears to show that we have a current level about 25% higher then at any time in the past 400,000 years."
-- --
Which shows that higher level has negligable effect on the temperature.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.