ESA's Swarm Satellites Begin To Monitor Earth's Magnetic Shield And Its Weakening

MessageToEagle.com - Fortunately, on Earth we have two very effective lines of defence: the Earth’s atmosphere and magnetic field that make our life possible on this planet.

Without this shield we cannot live on our planet.

However, research shows the magnetic field is weakening and scientists are trying to understand why. They would also like to understand how the geomagnetic field is evolving over time.

Some believe it signals a pole reversal in progress, not an uncommon phenomenon in the history of our planet. This has not happened for 780,000 years, but the phenomenon doesn't seem to be a regular occurrence through geological time.

The magnetic field and electric currents near Earth generate complex forces that have immeasurable impact on our everyday lives. Although we know that the magnetic field originates from several sources, exactly how it is generated and why it changes is not yet fully understood. ESA’s Swarm mission will help untangle the complexities of the field. ESA/ATG Medialab

The magnetic north and south poles wander about all the time, and every few hundred thousand years the poles flip around, so that a compass would point south instead of north.

Additionally, the strength of the geomagnetic field has decreased by 10–15 percent since ground measurements began around 1840, researchers say.

The lower pair will fly in formation side by side, about 150 km (10 seconds) apart at the equator and at an initial altitude of 460 km, while the upper satellite will rise to a higher orbit, at 530 km. Contact was established with the trio minutes later through the Kiruna station in Sweden and the Svalbard station in Norway. For four years, the Swarm will monitor Earth’s magnetic field, from the depth of our planet’s core to the heights of its upper atmosphere.

Artist's view of Swarm on a Rockot. Swarm is ESA's first Earth observation constellation of satellites. ESA/ATG Medialab

Their measurements will evaluate its current weakening and understand how it contributes to global change.

The Swarm satellites will give us unprecedented insights into the complex workings of the magnetic shield that protects our biosphere from charged particles and cosmic radiation.

“Swarm is about to fill a gap in our view of the Earth system and in our monitoring of global change issues,” noted Volker Liebig, ESA’s director for Earth observation. “It will help us to better understand the field that protects us from the particles and radiation coming from the Sun.”

Source: http://www.messagetoeagle.com/earthmagnfieldobservedesa.php#.UpSJosRFUdo

Sun's Global Magnetic Field Is About To Flip

  MessageToEagle.com - Something big is about to happen on the sun. According to measurements from NASA-supported observatories, the sun's vast magnetic field is about to flip."It looks like we're no more than 3 to 4 months away from a complete field reversal," says solar physicist Todd Hoeksema of Stanford University. "This change will have ripple effects throughout the solar system." The sun's magnetic field changes polarity approximately every 11 years. It happens at the peak of each solar cycle as the sun's inner magnetic dynamo re-organizes itself.
An artist's concept of the heliospheric current sheet, which becomes more wavy when the sun's magnetic field flips. More
The coming reversal will mark the midpoint of Solar Cycle 24. Half of 'Solar Max' will be behind us, with half yet to come.Hoeksema is the director of Stanford's Wilcox Solar Observatory, one of the few observatories in the world that monitor the sun's polar magnetic fields. The poles are a herald of change.
Just as Earth scientists watch our planet's polar regions for signs of climate change, solar physicists do the same thing for the sun.

Magnetograms at Wilcox have been tracking the sun's polar magnetism since 1976, and they have recorded three grand reversals—with a fourth in the offing. Solar physicist Phil Scherrer, also at Stanford, describes what happens: "The sun's polar magnetic fields weaken, go to zero, and then emerge again with the opposite polarity. This is a regular part of the solar cycle."A reversal of the sun's magnetic field is, literally, a big event. The domain of the sun's magnetic influence (also known as the "heliosphere") extends billions of kilometers beyond Pluto. Changes to the field's polarity ripple all the way out to the Voyager probes, on the doorstep of interstellar space.

When solar physicists talk about solar field reversals, their conversation often centers on the "current sheet." The current sheet is a sprawling surface jutting outward from the sun's equator where the sun's slowly-rotating magnetic field induces an electrical current.
The Sun's Magnetic Field is about to Flip
The current itself is small, only one ten-billionth of an amp per square meter (0.0000000001 amps/m2), but there’s a lot of it: the amperage flows through a region 10,000 km thick and billions of kilometers wide. Electrically speaking, the entire heliosphere is organized around this enormous sheet.During field reversals, the current sheet becomes very wavy. Scherrer likens the undulations to the seams on a baseball. As Earth orbits the sun, we dip in and out of the current sheet. Transitions from one side to another can stir up stormy space weather around our planet. Cosmic rays are also affected. These are high-energy particles accelerated to nearly light speed by supernova explosions and other violent events in the galaxy. Cosmic rays are a danger to astronauts and space probes, and some researchers say they might affect the cloudiness and climate of Earth. The current sheet acts as a barrier to cosmic rays, deflecting them as they attempt to penetrate the inner solar system. A wavy, crinkly sheet acts as a better shield against these energetic particles from deep space.As the field reversal approaches, data from Wilcox show that the sun's two hemispheres are out of synch. "The sun's north pole has already changed sign, while the south pole is racing to catch up," says Scherrer. "Soon, however, both poles will be reversed, and the second half of Solar Max will be underway."When that happens, Hoeksema and Scherrer will share the news with their colleagues and the public. Credits: Dr. Tony Phillips/Science@NASA
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See also:
Scientists Measure Sun’s Magnetic Field By Observing Solar Tsunami - A Rarely Seen Phenomenon

Source: http://www.messagetoeagle.com/sunabouttoflip.php