Earth's temperature follows it's magnetic field

Alain De Vos

A highly speculative idea i would like to propose, perhaps totally wrong.
Could it be that Earth's temperature rises when it's magnetic field decreases?
As the flows of Earth's metallic core change, it's magnetic field changes.
And currently the magnetic field is decreasing.
This decreasing in magnetic field allows more "solar energy" to arrive at the planet and this in turn increase the temperature of the Earth.
Please note I do not claim anything but if i have a link to reliable magnetic field data & temperature data i can check for a correlation.

Andre

No tine right now to subtantiate but there seems little corrolation at milleniun scales. More later.

check http://www.geo.uu.nl/~forth/publicat...s/Guyodo99.pdf

But that is not the final word

Studiot

What do you mean by the statement

"The Earth's magnetic field has decreased (or increased for that matter)" ?

Are you counting the total flux through a given hemi - spherical surface?

mfb

Solar energy is mainly light, which is not influenced by the magnetic field.
This does not exclude other mechanisms, but it is not as simple as you might think.

phlip180

I assume he's referring to the evidence that the Earth's magnetic field might currently be reversing, since measurements over the last 100 years have shown a drop in the strength of the Earth's magnetic field of about 5% (I remember it being about 5%. If someone has a more exact value, feel free to post it). Many Geologists believe this could mean the Earth's magnetic field is reversing, something it does roughly once every 100,000 years. Does that answer your question, Studiot?

Evo

Actually, the earth's magnetic field hasn't flipped for over 780,000 years and it is a very slow process. Also, the earth's magnetic field is not consistent.

http://en.wikipedia.org/wiki/Geomagnetic_reversal

It's very odd that the OP comes up with an idea apparently without having even done a rudimentary search.

For people learning about earth's magnetic field for the first time, the transcript of this NOVA show along with graphs and animations is very good.

http://www.pbs.org/wgbh/nova/magnetic/

More answers to questions

http://www-spof.gsfc.nasa.gov/Education/FAQs1.html#q9

phlip180

Sorry, I was actually just saying what my Geology professor told me. He said that SOME Geologists believe the Earth's magnetic field flips every 100,000 years or so. I was not trying to imply that the Earth's magnetic field actually does flip that fast, just that it is the opinion of at least a large handful of Geologists studying the Earth's magnetic field. No, I did not do an internet search to get this information which I probably should have, but I did get all that information directly from a Professor in Geology.

Andre

No it's not flipping every 100k years, it's collapsing roughly in that cycle, known as geomagnetic excursions, Also check my previous link. However the collapses don't appear match the 100k cycle seen in the isotopes of the marine sediment cores nor the Antarctic ice cores.

Evo

When I said OP, that's the "Opening post(er)", not you. That would be Alain.

And unfortunately professors can get their facts wrong.

ImaLooser

The reversal of magnetic fields is chaotic and (unlike the Sun) doesn't follow any cycle at all. It has roughly a Poisson distribution, which is a fancy way of saying that knowing the period of time since the last reversal tells you nothing about the imminence of the next. The current strength of the field is about half of the historical average. The current theory is that the iron core is of opposite polarity of the rest of the field and resists reversals.

The field doesn't collapse. Magnetic fields can survive supernova explosions and are just about indestructible. What happens is that the poles begin to move. Four or six poles may form. Charged particles from the Sun would be funneled to the surface at regions near the poles. I don't know what effect that would have.

Very little is known about specifics of what goes on inside the Earth. It is difficult to observe. We know more about distant galaxies.

Andre

see 4. Conclusion.

Note that we are not talking about geomagnetic reversals or flips, but geomagnetic excursions, which seem unique for this current Brunhes chron as they did not seem to have occured earlier.

See also fig 1, showing the accepted excursions with a rough average interval of 100ky

mfb

"every 100,000 years or so" and "not in the last 780000 years" could be true at the same time - the magnetic field is not a clock, it could switch on average once in 100000 years, but with some breaks in between.

Similar thing (but without possible underlying mechanics): It is expected that a supernova in our galaxy occurs about once every 50 years (source), but none was observed since 1604. Bad timing, as the first telescope was built in 1608.