Monday, November 3, 2008

Magnetic Portals

This is a delightful bit of science that is unexpected and it is certainly linked to the phenomena of the Northern lights.

I doubt if this is significant enough to impact on the cosmic ray flux, but we are rapidly learning that magnetic fields are much more dynamic than expected and that a feedback exists that can affect climate.

The textbooks will need a serious rewrite on this one. We now have portals between the Sun’s magnetic field and the Earth that just happens to coincide with the deepest part of winter. You could not ask for a better story for science class.

Magnetic Portals Connect Sun and Earth

Oct. 30, 2008: During the time it takes you to read this article, something will happen high overhead that until recently many scientists didn't believe in. A magnetic portal will open, linking Earth to the sun 93 million miles away. Tons of high-energy particles may flow through the opening before it closes again, around the time you reach the end of the page.

"It's called a flux transfer event or 'FTE,'" says space physicist David Sibeck of the Goddard Space Flight Center. "Ten years ago I was pretty sure they didn't exist, but now the evidence is incontrovertible."

Indeed, today Sibeck is telling an international assembly of space physicists at the 2008 Plasma Workshop in Huntsville, Alabama, that FTEs are not just common, but possibly twice as common as anyone had ever imagined.

Researchers have long known that the Earth and sun must be connected. Earth's magnetosphere (the magnetic bubble that surrounds our planet) is filled with particles from the sun that arrive via the solar wind and penetrate the planet's magnetic defenses. They enter by following magnetic field lines that can be traced from terra firma all the way back to the sun's atmosphere.

"We used to think the connection was permanent and that solar wind could trickle into the near-Earth environment anytime the wind was active," says Sibeck. "We were wrong. The connections are not steady at all. They are often brief, bursty and very dynamic."

Several speakers at the Workshop have outlined how FTEs form: On the dayside of Earth (the side closest to the sun), Earth's magnetic field presses against the sun's magnetic field. Approximately every eight minutes, the two fields briefly merge or "reconnect," forming a portal through which particles can flow. The portal takes the form of a magnetic cylinder about as wide as Earth. The European Space Agency's fleet of four Cluster spacecraft and NASA's five THEMIS probes have flown through and surrounded these cylinders, measuring their dimensions and sensing the particles that shoot through. "They're real," says Sibeck.

Now that Cluster and THEMIS have directly sampled FTEs, theorists can use those measurements to simulate FTEs in their computers and predict how they might behave. Space physicist Jimmy Raeder of the University of New Hampshire presented one such simulation at the Workshop. He told his colleagues that the cylindrical portals tend to form above Earth's equator and then roll over Earth's winter pole. In December, FTEs roll over the north pole; in July they roll over the south pole.

Sibeck believes this is happening twice as often as previously thought. "I think there are two varieties of FTEs: active and passive." Active FTEs are magnetic cylinders that allow particles to flow through rather easily; they are important conduits of energy for Earth's magnetosphere. Passive FTEs are magnetic cylinders that offer more resistance; their internal structure does not admit such an easy flow of particles and fields. (For experts: Active FTEs form at equatorial latitudes when the IMF tips south; passive FTEs form at higher latitudes when the IMF tips north.) Sibeck has calculated the properties of passive FTEs and he is encouraging his colleagues to hunt for signs of them in data from THEMIS and Cluster. "Passive FTEs may not be very important, but until we know more about them we can't be sure."

There are many unanswered questions: Why do the portals form every 8 minutes? How do magnetic fields inside the cylinder twist and coil? "We're doing some heavy thinking about this at the Workshop," says Sibeck.

Meanwhile, high above your head, a new portal is opening, connecting your planet to the sun.


mlinuxk said...

It has been obvious to me for many years that there must be electromagnetic coupling between the Sun and the planets and maybe even nearby stars. The Sun's magnetic fields are a result of the fusion reactions in the Sun's core. It is also obvious to me that the rotation of the planets is determinate on the existance of an magnetic core, Earth has an iron core and Jupiter has a hydrogen core, both magnetic and both rotate. Mars has a magnetic field and it rotates. Venus on the other hand does not has a magnetic field, it doesn't rotate and IMHO must not have a magnetic core. As to the Sun, in my mind, I can also see as cosmic connection between our star and the humongous magnetic field at the core of the galaxy. For that matter maybe even Galactic couplings may be the norm. As to variety of the solar winds and Sun spots, my opinion is that sun spots are the result of cyclic debris landing on the face of the Sun. The Sunspots are measureably cooler than the normal heliosphere and any matter deposited to the heliosphere would be vaporized and ejected into space; IE solar wind. This disposition of matter is consistant with observable phenonomen on Earth, Jupiter and other bodies by meteors, comets and asteroids. The cyclic nature of sunspots suggests the either there is a body of debris that revolves around the sun in an eleven year cycle or that the Sun it'self revolves around a common gravity point ( suggesting a binary or ternary system of stars of which our sun is part) and crosses a field of debris that is in the local part of our galaxy.

arclein said...

I always enjoy enthusiasm and a few comments are in order.

The assumption that planetary magnetism is generated by an iron core is just that.

I have posted alternative mechanisms that actually conform to magnetic fild observations and provide an explanation for pole shifting.

The debris concept is enticing but simply is an impossibility. The repetative pattern is conforming to a energy field pattern. A better explanation involves external magnetic fields and was recently published. I have not located the paper as yet but it appears compelling.

by the way, any debris would need to mass out at sizes capable of making earth sized splashes.

It is easy to forget just how big that sucker is.

mlinuxk said...

As this subject is highly complex, I am only probing around the edges.
The magnetic field is not a product of the iron core, but is of solar (nuclear) origin. The magnetic field of the core of a planetary body would be proportional flex density of the core material, the field strength of a star and the inverse of the distance separating the two bodies.
As for my second assumption, there would be no "splash" as the material would never actually reach the surface of the star. If, as I suppose, that solar luminosity is a product of the heliosphere and not the surface, any variations in gas density and gas composition would change the light output where the disruptions occur.