What else does the Magnetosphere Simulation tell us?

An earlier thread (www.abovetopsecret.com...) discussed the pressure representation of the Real Time Magnetosphere Simulation but pressure is only part of the interaction between the solar wind and the magnetosphere. There is another part of the simulation which catches a lot of attention, the magnetic field representation. The red and blue lines represent magnetic lines of force found within the Earth's magnetic field. To get an idea of the scale we are looking at, the loops on the left, the sunward side, are reaching out to a distance of about 50,000 miles from Earth's surface.

The solar wind carries with it its own magnetic field (the Interplanetary Magnetic Field), left over from when it left the surface of the Sun. When the IMF encounters the Earth's field some complex interactions take place. Close to the Earth, where the Earth's field is stronger, the IMF is not strong enough to have much influence and the Earth's field maintains is toroidal shape. Farther out the IMF dominates, dragging, stretching, and twisting the weaker field of the Earth.

The IMF is not constant. It changes in strength and polarity (the north/south) orientation. It is these changes which produce the changes in the magnetic field lines of Earth's magnetic field. The ACE satellite (which provides the data for the simulation) measures several aspects of the IMF but we are primarily concerned with the Bz component. This is the one that is oriented in the same plane (roughly) as the Earth's magnetic field. When the IMF has a northward orientation (the same as Earth's) the Earth's magnetic field repels the Sun's field. When the IMF has a southward orientation the two fields can connect through a process called magnetic reconnection. The stronger the Bz component, the stronger the connection or repulsion. This can be seen very clearly in the simulation. When there is a southward value in the Bz component the lines of force take on a splayed appearance. They are joining with the IMF and streaming far out into interplanetary space. When there is a northward value in the Bz this connection does not occur.

The lines of force are always shaped by the solar wind. With a southward Bz they hold hands with the Sun's field. With a northward orientation they keep to themselves. With a southward orientation we see the red and blue lines separating as they connect with the Sun's field instead of themselves. When we see the magnetic field lines forming a tight ball it does not mean the magnetosphere is collapsing, it means that it is not interacting with the solar wind as much. It means it is reverting to it's "natural" shape, the shape it would have if there were no solar wind at all.

Here is an example of the effects of a southward orientation:
[atsimg]http://files.abovetopsecret.com/images/member/ca2e24c82059.png[/atsimg]

Here is an example of a northward orientation:
[atsimg]http://files.abovetopsecret.com/images/member/7eb26ae69a03.png[/atsimg]


[edit on 8/5/2009 by Phage]

Good explanation Phage.... maybe while your at it you can explain why when the reversal of the suns IMF to Earth's it creates cracks in our magnetosphere. I seem to recall lately that scientists theories were kind of flawed of the late openings we have been having...... although it made for some nice Northern lights a few weeks back. Can you explain why it is creating these holes?

S & F Phage!

Thanks for the info and elaborating on the 'Magnetic Field Simulation' image.

so what then would the current image represent. I had a look, but looks unlike I had ever seen it before. Cannot put photo on here, so just go have a look

reply to post by raz24400

It means, as I said, that the solar wind has a strong northward orientation. This prevents the magnetosphere from reconnecting with it.

@airteck: I will get into some of the ramifications of the Bz orientation but I'm pressed for time right now. The main purpose of the thread is to explain what we're seeing in the simulation.

Thanks Phage..... I was just curious since you were describing the reversal effect on Earths magnetic waves you might have the insight on the cause for the holes. Just fishing for knowledge and appreciate all your contributions so far. keep up the great work.

reply to post by airteck

When the solar wind is southward, magnetic reconnection occurs. This reconnection forms a sort of conduit (not really a crack or a hole) through which the particles of the solar wind (ions and electrons) can travel. By moving through these pathways the particles are able to reach the inner regions of the magnetosphere where they become trapped. These connections come and go, sometimes only lasting minutes.

In June of 2007 the THEMIS satellites detected one of these reconnection conduits, the famous "breach". But it was not the reconnection which was really interesting (though this was a large one, they happen regularly), it was the fact that the solar wind had a northward orientation at the time. Before this, it had been theorized that magnetic reconnection could occur with a northward solar wind but the theories were verified by the THEMIS satellites (yea, science!). Just exactly how it came about is giving the theorists even more to play with.

So, what happens to these ions and electrons that get trapped and bounce around in the magnetosphere? Some of them, the ones closer to the magnetopause, get dragged back into the tail of the magnetosphere and rejoin the solar wind. Some, guided by the Earth's magnetic field, work their way toward the poles. At the poles the magnetic lines of force direct the particles downward into the upper atmosphere, the ionosphere. This is where the auroras occur. The particles which originated from the sun, got trapped by the magnetosphere and then forced to the polar regions, now find themselves surrounded by uncharged particles (atoms). When the solar particles (driven by the magnetic field) slam into these atoms they "precipitate", in the process producing the light show of the aurora.

[edit on 8/5/2009 by Phage]

Very helpful thread as always.

I am giving this thread a bump, because it is a good one and worth reading.

Thank you for posting this, Phage, I learned something from it.

My respects to you PHAGE nice job indeed.

reply to post by Phage

Hi,
Grettings from deltaman.
I have closely following all the threads in ATS.
I am not a very scientific person!!
I would like to know what does all this mean in layman's language?

reply to post by deltaman2000

It doesn't mean anything in particular. It is an attempt to explain what the magnetosphere simulation is representing. At various times, under various solar wind conditions, the "meaning" will be different.

It's become apparent from various threads and comments that there is very little understanding of what the simulation shows. People look at it, and without understanding what they are seeing, believe something strange or even dangerous is happening. The conditions seen earlier today are a perfect example. Because of a strong northward solar wind, the magnetic field representation took on a tightly balled up appearance. This led some to believe the magnetic field was collapsing when in fact its "defenses" against the solar wind were strengthened. Even though the solar wind was quite strong, we saw very little geomagnetic activity. This is typical of what happens when the solar wind displays these characteristics. Nothing has happened to the magnetic field, the simulation shows it responding the way it always does.

Thanks for clearing up all the bull$(*& phage. I hope all the magnetosphere disaster theorists read this and learn something!

S&F

reply to post by Phage

Thanks a lot for explaining this for ppl like me.
Good to know we are safe until now!!

S&F - this post really does deserve it.

I look for Phage's knowledge to reassure me when I find myself in threads that are filled with facts distorted to fit a doom leaden theory.

Originally posted by Merigold
S&F - this post really does deserve it.

I look for Phage's knowledge to reassure me when I find myself in threads that are filled with facts distorted to fit a doom leaden theory.

What he said.....

S+F well deserved.....thanx Phage

Peace

thank you phage i really appreciate you taking the time to write this thread out explaining what the pictures mean.

I have read this thread and in the process of reading some of your other threads. Now I'm starting to understand this more.
I would suggest others to take a peak at this. This has really helped me.

Thanks again Phage.