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European, Chinese Satellites Watch Solar Storms Pummel Earth

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Scientists have long understood that satellites are at risk from bombardment by solar storms. Now, they’ve gotten a closer look at how the storms are punishing Earth’s magnetosphere, leaving satellites exposed.

The movie above, and the solar flare video below, were released by the European Space Agency today, along with descriptions of two solar eruptions spotted using ESA’s four Cluster satellites and the two Chinese/ESA Double Star satellites. 

High-energy (X-3) solar flare on 13 December 2006. Credit: ESA/NASA/SOHO

High-energy (X-3) solar flare on 13 December 2006. Credit: ESA/NASA/SOHO

Under normal solar conditions, satellites orbit within the magnetosphere — the protective magnetic bubble carved out by Earth’s magnetic field. But when solar activity increases, the picture changes significantly: the magnetosphere gets compressed and particles get energized, exposing satellites to higher doses of radiation that can perturb signal reception.

Scientists have found that extreme solar activity drastically compresses the magnetosphere and modifies the composition of ions in the near-Earth environment. They are now challenged to model how these changes affect orbiting satellites, including the GPS system.

During two extreme solar explosions, or solar flares, on January 21, 2005 and December 13, 2006, the Cluster constellation and the two Double Star satellites were favorably positioned to observe the events on a large scale. 

During both events, the velocity of positively charged particles in the solar wind was found to be higher than 900 km (559 miles) per second, more than twice their normal speed. In addition, the density of charged particles around Earth was recorded at five times higher than normal. The measurements taken in January 2005 also showed a drastic change in ion composition. 

The second explosion in December 2006 released extremely powerful high-energy X-rays followed by a huge amount of mass from the solar atmosphere (called a coronal mass ejection). During the event, GPS signal reception on ground was lost. 

Typical nose-like ion structures in near-Earth space were washed out as energetic particles were injected into the magnetosphere. These nose-like structures, that had formed earlier in the ‘ring current’ in the equatorial region near Earth, were detected simultaneously on opposite sides of Earth. Measurements of the ring current showed that its strength had increased. 

These factors together caused the magnetosphere to be compressed. Data show that the ‘nose’ of the dayside magnetopause (the outer boundary of the magnetosphere), usually located about 60,000 km (40,000 miles) from Earth, was only 25,000 km (15,000 miles) away.

About five hours after the coronal mass ejection hit Earth’s magnetosphere, a Double Star satellite observed penetrating solar energetic particles on the night side. These particles are hazardous to astronauts as well as satellites.

“With these detailed observations, we’ll be able to plug in data and better estimate what happens to the inner magnetosphere and near-Earth space during such explosions on the Sun,” said Iannis Dandouras, principal investigator of the Cluster Ion Spectrometer and lead author on a paper about the findings. 

“Looking at such a large-scale physical phenomena with a single satellite is akin to predicting the impact of a tsunami with a single buoy,” added Matt Taylor, ESA’s Project Scientist for Cluster and Double Star. “With Cluster and Double Star we have monitored both sides of Earth simultaneously, and obtained valuable in-situ data.”

The results appear in the February 2009) issue of Advances in Space Research. The abstract is available here.

Source: ESA

Comments on this entry are closed.

  • Ian O'Neill April 29, 2009, 12:43 PM

    This conversation immediately jumps into my top 10 comment box debates of all time. “What’s your point?” “How can you get my point, when you don’t get my point?” “Exactly, I don’t get your point.” :D

  • tacitus April 29, 2009, 9:19 AM

    Fascinating, as a pointy-eared half-human bipedal alien would say.

    None of this is as sexy as human space flight, but it just shows how much of the work that’s going on now is valuable for when we do decide it’s time to make a concerted push into space. Understanding the effects of CMEs on the near-Earth environment is a critical part of the equation.

  • Jon Hanford April 29, 2009, 9:58 AM

    In light of desire for manned expeditions to the Moon and Mars, this research could be literally ‘life-saving’ when it comes to the astronauts exposed to this high energy radiation. But a deeper understanding of the cause and signs of an impending CME would greatly advance solar science.

  • TD April 29, 2009, 10:02 AM

    Did I see a plasmoid being ejected from the magnetosphere?

    Being careful to avoid censorship of a not-yet-mainstream theory which is closely related to one proposed over a hunderd years ago by Nobel prize winner Dr. Svante Arrhenius, it would be interesting to know the complete list of what that plasmoid might contain. Magnetic storms and the ionosphere not sexy enough? Finding the complete list of what a plasmoid might contain could be the greatest discovery in the history of science, bar none.

  • Anaconda April 29, 2009, 10:29 AM

    Bravo for the story and schematics. The schematics makes it all too clear this is an electromagnetic event.

    “Charged particles” are plasma as everybody knows.

    How do these charged particles have different velocities depending on the event?

    Could that have something to do with what is happening on the surface of the Sun?

    “…the ‘ring current’ in the equatorial region near Earth…” Let’s be clear: A ‘ring current’ is a “plasma torus” of charged particles, electric current.

    These electrical torus have been discovered on the Sun, Earth, Jupiter, and Saturn.

    You simply can’t describe or explain the dynamics of the Sun/Earth relationship without explaining electromagnetic processes and objects.

    Electromagnetism is essential to any attempted explanation and resulting understanding of the Sun/Earth dynamic.

    Notice something else about the story?

    Gravity isn’t mentioned once.

  • Jon Hanford April 29, 2009, 10:44 AM

    @Anaconda, I totally agree with your last post. What’s your point?

  • Anaconda April 29, 2009, 11:21 AM

    @ Jon Hanford:

    How can you totally agree with my post if you don’t undestand my point?

  • Jon Hanford April 29, 2009, 11:36 AM

    @ Anaconda, That’s why I’m asking, what’s your point? Duh.

  • Anaconda April 29, 2009, 11:51 AM

    Jon Hanford asks: “What’s your point?”

    “Electromagnetism is essential to any attempted explanation and resulting understanding of the Sun/Earth dynamic.”

    As I stated the first time.

  • Jon Hanford April 29, 2009, 12:29 PM

    @ Anaconda, Again, I don’t dispute what you are saying. Maybe you’re implying EM is the dominant force between the Earth and Sun. I really don’t know, since you don’t clarify things beyond what is generally accepted.

  • Anaconda April 29, 2009, 2:09 PM

    @ Jon Hanford:

    “@ Anaconda, Again, I don’t dispute what you are saying.”

    Good, all I’m saying is, “Electromagnetism is essential to any attempted explanation and resulting understanding of the Sun/Earth dynamic.”

    That’s pretty basic.

  • Aqua April 29, 2009, 3:42 PM

    WOW! 3D CME images! THAT is SO exciting!

    Isn’t it great to be alive to witness Mankind’s first steps into the universe! To see what has never been seenI I like!

  • Hon. Salacious B. Crumb April 29, 2009, 6:49 PM

    Anoconda said;
    “Charged particles” are plasma as everybody knows.”

    This is so fundamentally wrong. A plasma is in fact is a total excess of charge within a cloud of low pressure gas or ionised material under high temperatures.
    Examples in astronomy are say protons in the solar wind whose distribution under low density mans that the ionic state can be maintained without the interaction with other ionised atoms. Under high temperatures plasmas are highly ionised, not with one or two electrons but a fair percentage of them. Examples in the corona where I.e. Fe XX ions exist (nineteen electrons missing) or in the core of the Sun. Electrons in fact in the core of the Sun are not just ionised, but are free to roam in the so-called Fermi Sea. (This makes the solar core almost in a perfect plasma state.)
    This immediately discounts charged particles in solutions (chemistry) or ionic substances, and the chemical process known as dissociation. Chemical bonds are also not counted as plasma either, although in fact their existence is caused by transfer of electrons – not being ionised as such.
    Clarity on this is important, as EU proponents tend to taut this general idea EVERYTHING that is ionised is a plasma. It is not. By actually saying this common misconception (that everything is something plasma) somewhat finds a more generate support EU theory. (Solrey also tried to say this in another article in Universe Today.)
    CMEs are certainly plasma storms generated by the sun and the power generated is enormous. However, the true perspective against the energy output of the entire sun, well, these events are fairly low energetically speaking.

  • Lawrence B. Crowell April 29, 2009, 7:20 PM

    As much as I find Hanford’s comments here superior to most, I would take exception with the issue of sending astronauts to the planets. I think the whole manned space program is a somewhat questionable and expensive business.

    The animation has an interesting little bit. The magnetic field line in the trailing side of the magneto-pause bifurcates. There is some caustic event or the pinching off of the magnetic field line. I suppose a long wavelength EM field heads out away, and the pinching appears responsible for funnelling in charged particles to the geomagnetic poles or VanAllen belts. I suppose the 5 spaceprobes, I think named TREMIS or something similar, are designed to detect this physics.

    Lawrence B. Crowell

  • Anaconda April 29, 2009, 9:14 PM

    @ SBC:

    I stand corrected — yes, there are ionized particles that don’t constitute plasma.

    Perhaps, I should have written that plasma is constituted of charged particles.

    Does that address your concerns?

  • Astrofiend April 30, 2009, 12:55 AM

    I think we have to clarify definitions here – anal but important. I also agree with Anaconda’s posts – it is obvious that plasma, electromagnetic fields, etc etc is a fundamental aspect of the Earth/Sun dynamic – i.e how they influence and interact with each other and their environments in terms of electromagnetism. Note that this is ‘dynamic’, not ‘dynamics’ in the sense that we discuss ‘dynamics’ in physics – i.e. how objects respond to and move under the influence of forces. A claim that such electromagnetic phenomenon had a bearing upon the dynamics of the Earth/Sun system would be far more contentious…

  • solrey April 30, 2009, 10:54 AM

    @lbc
    OK, lets go with the pinched field line. Consider the “field lines” to actually be helical filaments of charged particles (field aligned current) following, and flowing through, the fluid-like contour of a magnetic field. As those filaments are directed around to the trailing cone of the magnetosphere they intersect and twist around each other. When the particle density (current density) is high enough, “kink” instabilities form in a z-pinch, between the twisted filaments, creating an intense expanding EM field encased in a double layer. The double layer rapidly becomes unstable/overloaded, (like overcharging an electronic balloon) the EM field collapses and explosively releases all of the energy within the magnetic containment in and around the pinch zone. Some of the charged particles are funneled into the poles and become dense enough to form dishcarge vortices, resulting in a current sheet in the ionosphere and that beautiful glow discharge of the aurora.

    So basically, magnetic reconnection is where field aligned current filaments interact within a magnetic field. :)

  • Lawrence B. Crowell April 30, 2009, 4:38 PM

    I think “explosive” is a bit hyperbolic. The helical currents are due to the Lorentz force on a charge

    F = qvxB

    which is normal or perpecdicular to the velocity and magnetic field line. For a significant flux of charged particles, which for a CME are at around the KeV range in energy, the charged particles act in part as a current which generates changes in the magnetic field. This is described by the Boltzmann-Vlasov equations.

    The trailing B field lines are drawn out to some limit and then once the particle flux drops it snaps back with a bifurcation in field lines. This is then a magnetic mirror for particles which funnels some back to the Earth.

    Lawrence B. Crowell

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