A Bizarre Idea About The Magnetic Field of The Earth

[Chineson]

I wonder the magnetic field of our earth may come not from the earth inside, but from the atmosphere.I think the magnetic field is a by-product of the rotating ionosphere and the sun wind. No atmosphere, no magnetic field.
How do we people here think about it?

[Nereid]

This idea would seem to have the merit of having not a skerrick (scintilla?) of good observational or experimental support for it, while simultaneously having a humongous amount of good observational and experimental support against it.

[hhEb09'1]

This idea would seem to have the merit of having not a skerrick (scintilla?) of good observational or experimental support for it, while simultaneously having a humongous amount of good observational and experimental support against it.One of the many accomplishments of the mathematician Gauss (whom we honor with the name of the unit of magnetic induction, the gauss) was to show using spherical harmonic analysis that the origin of the earth's magnetic field was internal rather than external.

PS: Here's a Univ. of Oklahoma geophysics webpage (http://geophysics.ou.edu/gravmag/mag_earth/mag_earth.html) that I googled, about this. I haven't read it yet.

[johntsang]

Existing data points to: Magnetic are planet's self effect, atmosphere is not the issue.

Willing to ponder ... any supporting ?


======================================
Love to Make Mistake.

[Gsquare]

..... No atmosphere, no magnetic field.
How do we people here think about it?

I think we ought to test it out just to make sure; he,he..

[Jerry]

I have openly speculated that the alignment of the earth's magnetic field is related to tidal forces, specifically wave actions. This is generally skoffed at, but it is not that bizarre of a hypothesis - there is not a good explanation for the alignment of magna, and most magnetic field anomalies occur on continental shelves.

[korjik]

a quick calculation would be to find out how much current is needed to generate the earths field and find out if the atmo has that kind of current.

Basically tho, I dont think the earths field wouldnt look like a dipole at ground level if it were generated in the atmo.

[hhEb09'1]

I have openly speculated that the alignment of the earth's magnetic field is related to tidal forces, specifically wave actions. Ocean waves?

Basically tho, I dont think the earths field wouldnt look like a dipole at ground level if it were generated in the atmo.No, I think it could. It's just not.

[Fram]

I wonder the magnetic field of our earth may come not from the earth inside, but from the atmosphere.I think the magnetic field is a by-product of the rotating ionosphere and the sun wind. No atmosphere, no magnetic field.
How do we people here think about it?

Mercury (http://www-spc.igpp.ucla.edu/personnel/russell/papers/merc_mag/) has a magnetic field, but no atmosphere...

[Gsquare]

And Venus has one of the most massive atmospheres and practically no magnetic field.
http://www-ssc.igpp.ucla.edu/personnel/russell/papers/venus_mag/

Gsquare

[Kesh]

Which I think pretty solidly kills the whole hypothesis dead. We already have an example of a planet without atmosphere or oceans that does have a strong magnetic field, and an example of a planet with a powerful, thick atmosphere and almost no magnetic field. Examine the rest of the planets, and I think we get enough of a sample size to rule out "atmosphere" as the primary source of magnetic fields, if it has any responsibility for their strength at all.

[Chineson]

Which I think pretty solidly kills the whole hypothesis dead. We already have an example of a planet without atmosphere or oceans that does have a strong magnetic field, and an example of a planet with a powerful, thick atmosphere and almost no magnetic field. Examine the rest of the planets, and I think we get enough of a sample size to rule out "atmosphere" as the primary source of magnetic fields, if it has any responsibility for their strength at all.

Thanks.

OK, Let's forget this thread and waste new visitors no more time .

[hhEb09'1]

Examine the rest of the planets, and I think we get enough of a sample size to rule out "atmosphere" as the primary source of magnetic fields, if it has any responsibility for their strength at all.I think the atmosphere (above the surface) can contribute to the magnetic field of a planet, and if the planet has no magnetic field internal to it, then the atmosphere would be the primary source of the magnetic field. In that instance.

[Kesh]

I think the atmosphere (above the surface) can contribute to the magnetic field of a planet, and if the planet has no magnetic field internal to it, then the atmosphere would be the primary source of the magnetic field. In that instance.
Care to quantify that? How is it that a planet with no inherent magnetic field would gain one through having an atmosphere?

[Chineson]

Care to quantify that? How is it that a planet with no inherent magnetic field would gain one through having an atmosphere?

But sun activities can affect the magnetic field through the atmosphere. That means atomosphere can also be an contributing element with the sun.

[Kesh]

Er, no. That's like saying, "Wind can affect the motion of a kite, which means kites contribute to creating the wind." Interaction does not mean it can create a magnetic field.

Besides, if it did, why is Venus' field so weak?

[hhEb09'1]

Besides, if it did, why is Venus' field so weak?I did not say that the earth's magnetic field is generated by its atmosphere, or even any strong magnetic field is generated by an atmosphere.

[Gsquare]

I think the atmosphere (above the surface) can contribute to the magnetic field of a planet, and if the planet has no magnetic field internal to it, then the atmosphere would be the primary source of the magnetic field. In that instance.

You are, however, correct about that hhEb; there can be a magnetic field in the 'ionosphere' of a planet, but it is a high altitude induced field which arises from its interaction with the solar wind. It is generally referred to as the 'magnetosphere'.
See again in the same link I previously posted under the heading "Solar wind Interaction".

G^2

[Chineson]

Besides, if it did, why is Venus' field so weak?

Maybe the ingredient of the atmosphere is an element? Venus's atmosphere is quite different.

[Omicron Persei 8]

The ingredient of Earth's atmosphere is many elements...nitrogen and oxygen in true diatomic form; most others in trace amounts. Venus's atmosphere is composed primarily of carbon dioxide. There is nothing in Earth's or Venus's atmosphere that could create a global magnetic field of such strength at its concentrations.

Beside, there are localized pockets of magnetic areas on Mars that seem to stem from past geologic activity. And remember that, like Mercury, Mars has almost no atmosphere (Mercury is actually much closer to a vacuum though).

[Kesh]

I did not say that the earth's magnetic field is generated by its atmosphere, or even any strong magnetic field is generated by an atmosphere.
I never brought up Earth, so I'm not sure why you used that as a counter-argument to my statement.

And you did state that "...if the planet has no magnetic field internal to it, then the atmosphere would be the primary source of the magnetic field." Strength was never brought up, but that still doesn't explain why you think the atmosphere would create a true magnetic field as we observe with the planets in our solar system.

[hhEb09'1]

I never brought up Earth, so I'm not sure why you used that as a counter-argument to my statement.This thread is about earth's magnetic field, but my comment also referred to any strong planetary magnetic field.
Strength was never brought up, but you asked, "why is Venus' field so weak?" Isn't that a question about strength?
but that still doesn't explain why you think the atmosphere would create a true magnetic field as we observe with the planets in our solar system.What's a false magnetic field? :)

I think Gsquare's last post, and their link (http://www-ssc.igpp.ucla.edu/personnel/russell/papers/venus_mag/), answers that, though. It says that the spacecraft measurements near Venus were primarily a result of the solar wind interaction with the planetary atmosphere.

[korjik]

You are, however, correct about that hhEb; there can be a magnetic field in the 'ionosphere' of a planet, but it is a high altitude induced field which arises from its interaction with the solar wind. It is generally referred to as the 'magnetosphere'.
See again in the same link I previously posted under the heading "Solar wind Interaction".

G^2

A magnetosphere is not an ionosphere interaction induced field. It is simply the area enclosed where the local field is controlled by the body involved.

What you are saying is backward. Mercury would have a very weak, very small magnetosphere, the Earth has a fairly strong 'sphere and Jupiter has a freakin huge 'sphere (would be bigger than the moon if you could see it). All of these fields are internally created. Venus does not have a magnetic field and does not have a magnetosphere. It does have a very active ionosphere. The magnetic fields generated due to the ion interactions isnt generally considered a magnetosphere tho

[Jerry]

Ocean waves?
No, I think it could. It's just not.
Not in a day, but over millennia - Mantle near the crust aligned by constant stroking from a very weak magnet. It would be interesting to study the changes in the directions of the magnetic field locked into frozen magna between the plates, and the drifting of the continents and the relative alignment with the moon...any grad students out there looking for a difficult thesis?

[hhEb09'1]

Ocean waves?
No, I think it could. It's just not.Not in a day, but over millennia - Mantle near the crust aligned by constant stroking from a very weak magnet. It would be interesting to study the changes in the directions of the magnetic field locked into frozen magna between the plates, and the drifting of the continents and the relative alignment with the moon...any grad students out there looking for a difficult thesis?My second comment (http://www.bautforum.com/showthread.php?p=685463#post685463) was a response to korjik. My question about ocean waves was whether you were asking about the ocean wave influence on the Earth's magnetic field.

The remnant magnetic field locked in the frozen magma has little to do with the earth's magnetic field as a whole--that is a local phenomenon. It would be like placing your compass near a bar magnet--the compass will be overwhelmed by the bar magnet field, but the bar magnet is insignificant relative to the earth's field.

[Gsquare]

A magnetosphere is not an ionosphere interaction induced field. ....
Venus ......does not have an magnetosphere.


"The 'magnetosphere' of Venus that was detected by spacecraft is now known to be an example of an 'induced' magnetosphere. In an induced magnetosphere, the solar wind interacts directly with the planetary ionosphere..."
Encyclopedia of Planetary Sciences, edited by J. H. Shirley and R. W. Fainbridge,
905-907, Chapman and Hall, New York, 1997.



Do you think we ought to believe the experts or believe you, korjik??

Try reading the links before before trying to tell other they are wrong, korjik; you may learn something.

Gsquare

[Jerry]

"The 'magnetosphere' of Venus that was detected by spacecraft is now known to be an example of an 'induced' magnetosphere. In an induced magnetosphere, the solar wind interacts directly with the planetary ionosphere..."
Encyclopedia of Planetary Sciences, edited by J. H. Shirley and R. W. Fainbridge,
905-907, Chapman and Hall, New York, 1997.



Do you think we ought to believe the experts or believe you, korjik??

Try reading the links before before trying to tell other they are wrong, korjik; you may learn something.

Gsquare
This one is really wide open - "the experts", at least many of them, tend to qualify their statements about the Earth's magnetic field, being careful to emphasize that 'the theory' lacks hard evidence. I agree Korjik and I should have a better understanding of the latest and greatest (thanks for the links), but there is nothing wrong with taking a hard look at this, especially since the moons of Jupiter and Saturn are clearly deeply impacted by the magnetic fields of the planets. It would be interesting to revisit Maxwell's proof.

[korjik]

"The 'magnetosphere' of Venus that was detected by spacecraft is now known to be an example of an 'induced' magnetosphere. In an induced magnetosphere, the solar wind interacts directly with the planetary ionosphere..."
Encyclopedia of Planetary Sciences, edited by J. H. Shirley and R. W. Fainbridge,
905-907, Chapman and Hall, New York, 1997.



Do you think we ought to believe the experts or believe you, korjik??

Try reading the links before before trying to tell other they are wrong, korjik; you may learn something.

Gsquare

I dont generally go off of an encyclopedia but what I was taught by space physicists, or what I can figure out on my own. I have never heared of an 'induced' magnetosphere, the few times I have heared Venus referenced it was that it was an ionosphere, and it didnt have a magnetosphere.

[Kesh]

This thread is about earth's magnetic field, but my comment also referred to any strong planetary magnetic field.

My post was solely about your assertion that the solar wind could create a magnetic field around a planet. I wasn't specifying Earth, as it made no sense given the examples put out earlier.


but you asked, "why is Venus' field so weak?" Isn't that a question about strength?

Which only came about due to your proposal that a magnetic field could be created. You seem to be bouncing back and forth on my posts.

Let's clarify then: You propose that the solar wind can create a magnetic field around a planet through interaction with the atmosphere. This is quite against conventional understanding of how planetary magnetic fields work. The question is thus, why would a planet with such a thick, active atmosphere have a weak field, while a planet with a thin atmosphere closer to the Sun has such a strong one? It seems backwards to reason.


What's a false magnetic field? :)

Non-sequitur. If you like, strike out the word "true" from my post. The point still stands.


I think Gsquare's last post, and their link (http://www-ssc.igpp.ucla.edu/personnel/russell/papers/venus_mag/), answers that, though. It says that the spacecraft measurements near Venus were primarily a result of the solar wind interaction with the planetary atmosphere.

It seems like quite an assumption to me. Admittedly, I am not a physicist, but I see nothing in there that indicates the solar wind is causing the magnetic field, merely that the measurements taken were picking up the interaction between the solar wind and the atmosphere. It'd be nice if some of the physicists on the board could actually run the numbers.

There's no argument that the solar wind causes interesting effects with our own planet's atmosphere & magnetic field. The question still remains: what is the basis for the hypothesis that the solar wind can create a planet's magnetic field through interaction with the atmosphere?

[Kesh]

Addendum: I haven't had a chance to read through the link in detail, just skim it. Once I get the chance, I'll have a better grasp of what the paper actually claims. From a brief glance, though, I don't think it supports the original premise.

[hhEb09'1]

My post was solely about your assertion that the solar wind could create a magnetic field around a planet.That wasn't my assertion, that was the assertion at the link that Gsquare provided.

Non-sequitur. If you like, strike out the word "true" from my post. The point still stands.Non-sequitur? I only asked because you mentioned true magnetic field. If a "true magnetic field" meant one that is generated inside the planet, then I would have just agreed--the atmosphere would not produce a true magnetic field in that sense.

A magnetic field can be generated by a movement of charged particles. If there are charged particles in the atmosphere, then it seems reasonable that they could produce a magnetic field, however weak.

[Kesh]

That wasn't my assertion, that was the assertion at the link that Gsquare provided.

An assertion which you have since defended. Forgive me if that leads me to believe you agree with the assertion.


Non-sequitur? I only asked because you mentioned true magnetic field. If a "true magnetic field" meant one that is generated inside the planet, then I would have just agreed--the atmosphere would not produce a true magnetic field in that sense.

And, as I said, you can strike the word "true" from my statement. Perhaps it was a poor choice of words. A field generated inside the planet and surrounding the planet is what the point of the discussion is about.


A magnetic field can be generated by a movement of charged particles. If there are charged particles in the atmosphere, then it seems reasonable that they could produce a magnetic field, however weak.

There's a difference between a planetary magnetic field, and just "a magnetic field." See above: we're discussing a field that surrounds the planet. Conventional theory places this origin within the planet itself. The OP's link asserts that it's due to the solar wind instead.

Interaction of the solar wind with the atmosphere does introduce small magnetic fields... but not a full planetary field.

[DrMars]

Although the present magnetic field of the earth is not created by the ionosphere, the latter has a small but noticeable influence on it which leads to magnetic field variations of the order of 100 nanoTesla (less than 1% of the earth's magnetic field). The solar wind can even lead to magnetic 'storms' of the order of 1000 nT, but this still presents only a minor disturbance (see http://www.spaceweather.gc.ca/variations_e.shtml for more).

However, a couple of years ago, a theoretical scientific paper showed that if the earth itself would have no magnetic field (as it might happen for some time when the magnetic field reverses in the future), the interaction of the solar wind with the ionosphere could create a magnetic field of the same order of magnitude as the present one (see http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2004A%26A...420L..15B ) . So in this sense, Chineson's idea was really not so bizarre after all.

[hhEb09'1]

An assertion which you have since defended. Forgive me if that leads me to believe you agree with the assertion.No, I think I only mentioned it. I haven't defended it yet.
And, as I said, you can strike the word "true" from my statement. Perhaps it was a poor choice of words.So was "non-sequitur" :)
A field generated inside the planet and surrounding the planet is what the point of the discussion is about.But that was what I was trying to get at. Isn't the question in the OP about just the opposite, a field generated outside the solid planet? Or are you including the atmosphere when you say inside the planet?
There's a difference between a planetary magnetic field, and just "a magnetic field." See above: we're discussing a field that surrounds the planet. Conventional theory places this origin within the planet itself. The OP's link asserts that it's due to the solar wind instead.Which link? I do not see a link in the OP, or by the OP. Was the post changed?

[Kesh]

Never mind. I'm done trying to parse whatever point you may have had, hhEb09'1.

[hhEb09'1]

Hey, that's my line.

The first sentence of the webpage I linked (http://geophysics.ou.edu/gravmag/mag_earth/mag_earth.html) in my first post to this thread said "1838, Carl Friedrich Gauss proved 95% of Earth's magnetic field is internal, 5% external."

I'm not sure what the exact numbers are currently, but it looks like somewhere between 1 and 5 per cent of the earth's magnetic field is not internally generated. That's fairly significant, but no one is trying to say that the earth's field is primarily external. That may be the case on other planets, though, especially where the field is weak.