Scientists identify a plasma plume that naturally protects the Earth against solar storms

Mar 06, 2014 by Jennifer Chu
NASA's THEMIS mission observed how dense particles normally near Earth in a layer of the uppermost atmosphere called the plasmasphere can send a plume up through space to help protect against incoming solar particles during certain space weather events. Credit: NASA/Goddard Space Flight Center

The Earth's magnetic field, or magnetosphere, stretches from the planet's core out into space, where it meets the solar wind, a stream of charged particles emitted by the sun. For the most part, the magnetosphere acts as a shield to protect the Earth from this high-energy solar activity.

But when this field comes into contact with the sun's —a process called ""—powerful electrical currents from the sun can stream into Earth's atmosphere, whipping up geomagnetic storms and space weather phenomena that can affect high-altitude aircraft, as well as astronauts on the International Space Station.

Now scientists at MIT and NASA have identified a process in the Earth's that reinforces its shielding effect, keeping incoming solar energy at bay.

By combining observations from the ground and in space, the team observed a plume of low-energy particles that essentially hitches a ride along magnetic field lines—streaming from Earth's lower atmosphere up to the point, tens of thousands of kilometers above the surface, where the planet's magnetic field connects with that of the sun. In this region, which the scientists call the "merging point," the presence of cold, dense plasma slows magnetic reconnection, blunting the sun's effects on Earth.

"The Earth's magnetic field protects life on the surface from the full impact of these solar outbursts," says John Foster, associate director of MIT's Haystack Observatory. "Reconnection strips away some of our magnetic shield and lets energy leak in, giving us large, violent storms. These plasmas get pulled into space and slow down the reconnection process, so the impact of the sun on the Earth is less violent."

Foster and his colleagues publish their results in this week's issue of Science. The team includes Philip Erickson, principal research scientist at Haystack Observatory, as well as Brian Walsh and David Sibeck at NASA's Goddard Space Flight Center.

A thin layer of cold, dense material called the plasmasphere surrounds Earth. Researchers have found that material in the plasmasphere can help prevent particles from the sun crossing into near Earth space. Credit: NASA

Mapping Earth's magnetic shield

For more than a decade, scientists at Haystack Observatory have studied plasma plume phenomena using a ground-based technique called GPS-TEC, in which scientists analyze radio signals transmitted from GPS satellites to more than 1,000 receivers on the ground. Large space-weather events, such as , can alter the incoming radio waves—a distortion that scientists can use to determine the concentration of plasma particles in the upper atmosphere. Using this data, they can produce two-dimensional global maps of atmospheric phenomena, such as plasma plumes.

These ground-based observations have helped shed light on key characteristics of these plumes, such as how often they occur, and what makes some plumes stronger than others. But as Foster notes, this two-dimensional mapping technique gives an estimate only of what space weather might look like in the low-altitude regions of the magnetosphere. To get a more precise, three-dimensional picture of the entire magnetosphere would require observations directly from space.

This is an artist's rendition of the THEMIS spacecraft in orbit in Earth's magnetosphere. Credit: NASA

Toward this end, Foster approached Walsh with data showing a plasma plume emanating from the Earth's surface, and extending up into the lower layers of the magnetosphere, during a moderate solar storm in January 2013. Walsh checked the date against the orbital trajectories of three spacecraft that have been circling the Earth to study auroras in the atmosphere.

As it turns out, all three spacecraft crossed the point in the magnetosphere at which Foster had detected a plasma plume from the ground. The team analyzed data from each spacecraft, and found that the same cold, dense plasma plume stretched all the way up to where the solar storm made contact with Earth's magnetic field.

A river of plasma

Foster says the observations from space validate measurements from the ground. What's more, the combination of space- and ground-based data give a highly detailed picture of a natural defensive mechanism in the Earth's magnetosphere.

"This higher-density, cold plasma changes about every plasma physics process it comes in contact with," Foster says. "It slows down reconnection, and it can contribute to the generation of waves that, in turn, accelerate particles in other parts of the magnetosphere. So it's a recirculation process, and really fascinating."

Foster likens this plume phenomenon to a "river of particles," and says it is not unlike the Gulf Stream, a powerful ocean current that influences the temperature and other properties of surrounding waters. On an atmospheric scale, he says, plasma particles can behave in a similar way, redistributing throughout the atmosphere to form plumes that "flow through a huge circulation system, with a lot of different consequences."

"What these types of studies are showing is just how dynamic this entire system is," Foster adds.

Explore further: Researchers find planet-sized space weather explosions at Venus

More information: "Simultaneous Ground- and Space-Based Observations of the Plasmaspheric Plume and Reconnection" Science, 2014.

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User comments : 24

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Newbeak
3 / 5 (1) Mar 06, 2014
Sadly,it isn't 100% effective: a Carrington Event is still possible:http://news.natio...science/
Q-Star
5 / 5 (10) Mar 06, 2014
Scientists identify a plasma plume,,,,,,,,,


Oh boy, here we go,,,,,, (it's a good thing they aren't astrophysicists, oh, they are.)
orti
1.5 / 5 (8) Mar 07, 2014
"The Earth's magnetic field protects life on the surface from the full impact of these solar outbursts,"
Nice coincidence. Might even think the anthropic principle.
SoylentGrin
4.9 / 5 (8) Mar 07, 2014

Nice coincidence. Might even think the anthropic principle.

Look at it this way: There are many favorable conditions for life to exist here on Earth. Why do people constantly seem surprised or call it miraculous that life exists here then?
A miracle would be life existing where it can't, not where it can.
orti
1 / 5 (6) Mar 07, 2014
I think you're tilting at your own straw man, talking miracles. But I'll go along. To me the fact that there is something rather than nothing is astounding. Why should it be so?
orti
1 / 5 (6) Mar 07, 2014
Meaning, I look at the character of what is from that standpoint.
Maggnus
4.6 / 5 (9) Mar 07, 2014
Oh oh, "plasma" in the title, no doubt a clown from the EU crowd will see this as an invitation to spout more sciency sounding gobbly-gook along with claims it has never been considered by scientists and similar.

And "plasma plume" will likely entice Zephyr to talk about nuclear fusion initiation by neutrinos and dark matter particles. Oh wait, no, that's in the oceans....
Maggnus
4.6 / 5 (9) Mar 07, 2014
Look at it this way: There are many favorable conditions for life to exist here on Earth. Why do people constantly seem surprised or call it miraculous that life exists here then?
A miracle would be life existing where it can't, not where it can.
That leads to an interesting quandary; the "but for" issue. Many say that life on Earth s special because of certain aspects of Earth. For example, "but for" the moon the Earths stable orbital axis would not have occurred, or "but for" Earth's magnetic field the conditions leading to life might not have occurred.

The thing is, these conditions are required for Earth life, but they are not "necessarily" required for life elsewhere. My point is that just because life on Earth evolved in concert with the conditions of Earth does not necessarily mean that life elsewhere will require those same particular set of conditions.
Maggnus
4.5 / 5 (8) Mar 07, 2014
So to say that "There are many favorable conditions for life to exist here on Earth" is true, but logically inconsistent - the conditions for Earth's life are favourable for life on Earth because Earth's life evolved on Earth, but that does not necessarily mean the conditions of Earth are necessarily required for life elsewhere.

Lol look at me all waxing poetic!
GSwift7
5 / 5 (11) Mar 07, 2014
Hey, whatta-ya-know, I'll be darned. They made a prediction based on limited evidence and theory, then they launched a spacecraft to check it out. Wow, the observations matched the theory.

Surely there's some mis-understanding here. They didn't mention Birkland currents or anything like that, so I'm sure they're using models that don't work. The fact that their model predicted the plumes prior to observing them is purely a matter of making the data fit their flawed models, I'm sure. Those tricky astrophysicists are at it again!

So the question that springs to mind is: Can we use this information to help protect people in deep space? Maybe?
GSwift7
5 / 5 (8) Mar 07, 2014
The thing is, these conditions are required for Earth life, but they are not "necessarily" required for life elsewhere


If we ever want to get off this planet, we better hope that every habitable body in space isn't crawling with extraterrestrial microbes and such.

Wouldn't it be ironic if the reason the entire galaxy hasn't already been conquered by some advance civilization before us is due to the fact that every nice planet is crawling with potentially deadly microbes? If life is pervasive, I wouldn't be surprised if life from one planet would have a difficult time out-competing the native species. There are lots of microbes inside our bodies that we need to survive, so for example, if you got infected with an alien microbe that killed off some of your internal microbes, you'd be in trouble.
Maggnus
4.4 / 5 (7) Mar 07, 2014

There are lots of microbes inside our bodies that we need to survive, so for example, if you got infected with an alien microbe that killed off some of your internal microbes, you'd be in trouble.
Yea, for sure. The show "Alien" suggested a life form that could incubate in a human host, but it was gigantic. The real "Alien" might be only 5 microns long - but it wouldn't be very cinematically pleasing to watch that "burst" out of a human stomach lol!
VCRAGAIN
1.4 / 5 (9) Mar 09, 2014
The comment on the EU(Electric Universe) by magnus : Can he explain how the mainstream are NOW spouting 'magnetism' all over the place, but they refuse to acknowledge the concept of electric currents causing that magnetism - this science is evolving very rapidly and if you just wait and watch carefully you will see the mainstream gradually adding the concept of electric currents into their conversation - I will be laughing !
cantdrive85
1.4 / 5 (9) Mar 09, 2014
This first paragraph or so from an Alfven paper largely describe the dynamics reported above;
"Since the time of Langmuir, we know that a double layer is a plasma formation by which a plasma -- in the physical meaning of this word -- protects itself from the environment. It is analogous to a cell wall by which a plasma -- in the biological meaning of this word -- protects itself from the environment. If an electric discharge is produced between a cathode and an anode (Fig. 2) there is a double layer, called a cathode sheath, produced near the cathode that accelerates electrons which carry a current through the plasma. A positive space charge separates the cathode sheath from the plasma. Similarly, a double layer is set up near the
anode, protecting the plasma from this electrode. Again, a space charge constitutes the border between the double layer and the plasma. All these double layers carry electric currents."
The Earth being a charged sphere and protecting itself from the solar plasma is the reason for the earth's EM field and the series of DL's (plasmasphere, ionosphere, etc.) it has.
orti
1.7 / 5 (6) Mar 09, 2014
Maggnus, It's OK to be poetic at times. Says a lot with few words. And sometimes things that can't be said with words.
But you make an argument I can't agree with. The same argument the evolutionists make. "You did it right, therefore you exist -- you exist, therefore you did it right. Natural forces explain everything." The trick is so effective that the cosmologist have copped it to explain away the anthropic principal. No less than Stephen Hawking backs an infinite number of universes each with slightly different laws. Therefore, the one we know must be the one conducive to life.
They have to come up with something better than circular logic to convince me.
orti
1.7 / 5 (6) Mar 09, 2014
Natural laws are not sufficient to explain everything. Where did the natural laws come from?
Captain Stumpy
4.4 / 5 (7) Mar 09, 2014
this science is evolving very rapidly and if you just wait and watch carefully you will see the mainstream gradually adding the concept of electric currents into their conversation - I will be laughing!

@VCRAGAIN
conjecture based upon ignorance
the EU is written/supported by Electrical Engineers (EE) who have NO CONCEPT or idea of WHY their philosophy is wrong, given that they have no knowledge of Astrophysics
EE's do NOT study astrophysics, whereas Astrophysicists DO STUDY PLASMA PHYSICS
this has been proven over and over, on this site alone
see: http://phys.org/n...ggs.html
read the comments
Therefore the only thing that will happen in the future is:
EITHER they will have to change their philosophy to include astrophysical data that they ignore at this time
OR
(like now) everyone will be laughing at them/you as it is PSEUDOSCIENCE
DeliriousNeuron
2.3 / 5 (6) Mar 10, 2014
EU Theory has its place in astrophysics. Time will only prove it.
thermodynamics
4.2 / 5 (5) Mar 10, 2014
The comment on the EU(Electric Universe) by magnus : Can he explain how the mainstream are NOW spouting 'magnetism' all over the place, but they refuse to acknowledge the concept of electric currents causing that magnetism - this science is evolving very rapidly and if you just wait and watch carefully you will see the mainstream gradually adding the concept of electric currents into their conversation - I will be laughing !

VCRAGIN:

Just to add to the point that Astrophysics does recognize plasma physics, go to the MIT open courseware site for astrophysics and see two courses on their web site. They also have more advanced courses for the advanced students.

http://ocw.mit.ed...ophysics

They consider the first two courses "introductory." Take a look at them and let us know if you can survive one of their "introductory" courses.
VCRAGAIN
2.5 / 5 (8) Mar 10, 2014
captainstumpy: seems to me that the astro* world is furiously doing mathematical formulas to prove their 'ideas', which do not make me feel confident that they actually are doing REAL science via physical testing ! They basically just 'imagine' what could be going on out there and try to get the math make it look good. The main point in this discussion is NOT that we should be taking a side and yelling as loud as possible but to CONSIDER ALL IDEAS thrown out without bias, without only math to 'prove' an idea - doesn't prove anything except that they can do math. "they are not astrophysicists" smacks of professional snobbery and a very small mind - many a revolutionary concept has been shown in time to be actually the TRUTH - let's just keep looking for the facts and STOP being the usual a**h*** that sticks the nose in the air and tries to be the 'top dog'.
GSwift7
5 / 5 (6) Mar 10, 2014
The Earth being a charged sphere and protecting itself from the solar plasma is the reason for the earth's EM field and the series of DL's


That doesn't make any sense when you take into account the electromagnetic environments around other bodies in the solar system. It doesn't make sense for a lot of reasons, but you can directly prove that Alfven's guess was wrong by observing the other planets, moons, etc. Once again, Alfven would have known better if he lived at a time with better observations. Much of what he thought at the time was based on faulty assumptions and incomplete information about the electromagnetic environment of the Earth.
Captain Stumpy
4.4 / 5 (7) Mar 10, 2014
They basically just 'imagine' what could be going on out there and try to get the math make it look good.

@VCRAGAIN
nope. Perhaps you missed these links:
http://w3fusion.p...edu/ifs/
http://ve4xm.calt...ma_page/
they show that the plasma physics astro* use are tested/proven
it is only the EU (and other pseudoscience sites) that claim that astro* dont know about plasma physics and do their testing etc.
a common misconception for IEEE as well, as they concentrate mostly on engineering, and are not suited for impacting astrophysics
"they are not astrophysicists" smacks of professional snobbery and a very small mind ...STOP being the usual a**h*** that sticks the nose in the air and tries to be the 'top dog'.

not trying to be a top dog
BUT pushing PSEUDOSCIENCE on a science site SMACKS of being an IDIOT and CRACKPOT TROLL
see arguments made by Tim Thompson: formerly of JPL in my comment above link
http://phys.org/n...ggs.html
Captain Stumpy
4.3 / 5 (6) Mar 10, 2014
The main point in this discussion is NOT that we should be taking a side and yelling as loud as possible but to CONSIDER ALL IDEAS thrown out without bias, without only math to 'prove' an idea - doesn't prove anything except that they can do math.

@VCRAGAIN
I understand where you are coming from, however, IEEE/EU does NOT address all the tiny little things that astrophysics does, because they approach from an engineering point of view, which EXCLUDES certain factors that MUST be addressed. Astrophysicists are not trying to engineer a better playstation/whatever, they are concerned about factors that EE's never trained/studied to consider.
It is the difference between hiring a plumber to fix your plumbing in your home and hiring a Firefighter...BOTH know quite a bit about plumbing and how water works, but FF's are concerned with SEPARATE issues/circumstances and they never learn everything that plumbers learn; FF's learn only enough to do their job effectively.
cantdrive85
1 / 5 (3) Mar 13, 2014
That doesn't make any sense when you take into account the electromagnetic environments around other bodies in the solar system. It doesn't make sense for a lot of reasons, but you can directly prove that Alfven's guess was wrong by observing the other planets, moons, etc.


Why? Are you suggesting that every body MUST have the same reaction to it's local environment regardless of it's properties? Venus has a dense atmosphere but no strong magnetic field as the earth does, why? Probably because Venus doesn't rotate fast enough to generate the homopolar motor action such that the Earth does to create such a field. As Alfven mentioned there are innumerable combinations of plasma interactions.

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