Ares
13th October 2010, 04:20 PM
Solar Cycles and the Earth's
Weakening Magnetic Field
The emerging Solar Cycle 24, combined with our planet's declining magnetic field, may have severe consequences for Earth in terms of climate, electricity grid systems and human behaviour.
If you were thinking that the only things we have to be concerned about include wars, famines and economic crashes, think again. Recent scientific discoveries are indicating that this next solar flare cycle could be powerful enough to disrupt our planet's entire electric grid. In this report I document a number of changes taking place with the Earth's magnetic field, the Sun and our solar system while explaining some of the concerns that today's leading scientists have voiced. I also examine how humankind may be affected energetically.
Our Planet's Magnetic Field
The magnetosphere is a bubble of magnetism that surrounds the Earth and protects us from solar wind. Fortunately, our planet's magnetic field diverts most particles into a circular path around the Earth. Like weather patterns found on Earth, solar wind patterns can change rapidly.
Luckily, our planet's magnetosphere quickly responds to the threat and absorbs the impact, wiggling and jiggling in the process. Geophysicists call this reaction a geomagnetic storm, but because of how it disrupts the Earth's magnetic field it could also be called electromagnetic pollution.
This is when we see the Aurora Borealis in our night skies.
But strange things are happening in both outer and inner space. The Earth's magnetic field has been weakening. This decrease actually began 2,000 years ago, but the rate of decrease suddenly became much more rapid 500 years ago. However, in the last 20 years or so, the magnetic field has become erratic.
Aeronautical maps of the world, which are used to allow aeroplanes to land using automatic pilot systems, have had to be revised globally in order for the autopilot systems to work.
Now, NASA's five THEMIS spacecraft have discovered a breach in the Earth's magnetic field that is 10 times larger than anything previously thought to exist. When this happens, solar wind can flow in through the opening to "load up" the magnetosphere for powerful geomagnetic storms.
Exploring the mystery is a key goal of the THEMIS mission, launched in February 2007.
The big discovery came on 3 June 2007, when the five probes serendipitously flew through the breach just as it was opening. Onboard sensors recorded a torrent of solar wind particles streaming into the magnetosphere, signaling an event of unexpected size and importance.
But the breach itself is not the biggest surprise. Researchers are even more amazed and baffled at the unexpected way it forms, overturning longheld ideas of space physics.
"At first I didn't believe it," said THEMIS project scientist David Sibeck of the Goddard Space Flight Center. "This finding fundamentally alters our understanding of the solar wind-magnetosphere interaction."
"The opening was huge—four times wider than Earth itself," said Wenhui Li, a space physicist at the University of New Hampshire, who has been analysing the data. Li's colleague Jimmy Raeder, also of the University of New Hampshire, said: "127 particles per second were flowing into the magnetosphere—that's a 1 followed by 27 zeros. This kind of influx is an order of magnitude greater than what we thought was possible."
Space physicists have long believed that holes in the Earth's magnetosphere open only in response to solar magnetic fields that point south. The great breach of June 2007, however, opened in response to a solar magnetic field that pointed north. To the layperson this may sound like a quibble, but to a space physicist it is almost seismic.
Unexpected Shield Drop
Regarding how our magnetic field is changing, what is understood today in the scientific community is that the solar wind presses against the Earth's magnetosphere almost directly above the equator, where our planet's magnetic field points north.
Scientists previously believed that if a bundle of solar magnetism came along and pointed north, too, the two fields should reinforce one another, strengthening the Earth's magnetic defences and slamming the door shut on the solar wind. In the language of space physics, a north-pointing solar magnetic field is called a "northern IMF" (interplanetary magnetic field) and it is synonymous with "shields up".
The big surprise is that when a northern IMF came along, the shields went down. This has completely overturned many scientists' understanding of things.
As researchers investigated the tear in the magnetic field, they discovered that 20 times more solar wind passed into the Earth's protective shield when the magnetic fields were aligned.
Northern IMF events don't actually trigger geomagnetic storms, Raeder noted, but they do set the stage for storms by loading the magnetosphere with plasma. A loaded magnetosphere is primed for auroras, power outages and other disturbances that can result when a CME (coronal mass ejection) hits.
This means that the impact of solar flares is 20 times as strong when the magnetic fields are aligned. The Earth's and the Sun's magnetic fields will be in sync at the peak of Solar Cycle 24, expected in 2012. This will cause an influx of solar particles. What the scientists didn't discuss is the impact on the human bioelectrical system.
Earth's Magnetic Field Changes Climate
The Earth's climate has been significantly affected by the planet's magnetic field, according to a Danish study published in January 2009 which could challenge the notion that human emissions are responsible for global warming.
"Our results show a strong correlation between the strength of the Earth's magnetic field and the amount of precipitation in the tropics," one of the two Danish geophysicists behind the study, Mads Faurschou Knudsen of the geology department at Aarhus University in Denmark, told Videnskab journal.
The results of the study (also published in the US scientific journal Geology) lend support to a controversial theory published a decade ago by Danish astrophysicist Henrik Svensmark, who claimed that the climate is highly influenced by galactic cosmic ray (GCR) particles penetrating the Earth's atmosphere.
Geomagnetic Field Reversal
Another recent study suggests that rapid changes in the churning movement of the Earth's liquid outer core are weakening the magnetic field in some regions of the planet's surface.
"What is so surprising is that rapid, almost sudden, changes take place in the Earth's magnetic field," said study co-author Nils Olsen, a geophysicist at the Danish National Space Center in Copenhagen. The findings suggest similarly quick changes are simultaneously occurring in the liquid metal, 1,900 miles (3,000 kilometres) below the surface, Olsen said. Fluctuations in the magnetic field have occurred in several far-flung regions of the Earth.
The changes "may suggest the possibility of an upcoming reversal of the geomagnetic field" said study co-author Mioara Mandea, a scientist at the German Research Centre for Geosciences in Potsdam. Earth's magnetic field has reversed hundreds of times over the past billion years, and the process could take thousands of years to complete.
The decline in the magnetic field is also opening the Earth's upper atmosphere to intense charged-particle radiation, according to scientists.
Cosmic Rays Slam the Earth
An international team of researchers has discovered a puzzling surplus of high-energy electrons bombarding Earth from space. The source of these cosmic rays is unknown, but it must be close to the solar system and could be made of dark matter. The results were reported in the 20 November 2008 issue of the journal Nature.
"This is a big discovery," said co-author John Wefel of Louisiana State University. "It's the first time we've seen a discrete source of accelerated cosmic rays standing out from the general galactic background." To study the most powerful and interesting cosmic rays, Wefel and colleagues spent the last eight years flying a series of balloons through the stratosphere over Antarctica. Their NASA-funded cosmic ray detector found a significant surplus of high-energy electrons.
"The source of these exotic electrons must be relatively close to the solar system—no more than a kiloparsec away," said co-author Jim Adams of the NASA Marshall Space Flight Center.
Galactic cosmic rays are subatomic particles accelerated to almost light- speed by distant supernovae explosions and other violent events. They swarm through the Milky Way, forming a haze of high energy particles that enter the solar system from all directions. Cosmic rays consist mostly of protons and heavier atomic nuclei with a dash of electrons and photons spicing the mix. Why must the source be nearby?
According to Adams: "High-energy electrons lose energy rapidly as they fly through the galaxy. They give up energy in two main ways: (1) when they collide with lower-energy photons, a process called inverse Compton scattering; and (2) when they radiate away some of their energy by spiralling through the galaxy's magnetic field." High-energy electrons are therefore local, but the researchers cannot pinpoint the source in the sky.
The Sun's Magnetic Field
Weakening Magnetic Field
The emerging Solar Cycle 24, combined with our planet's declining magnetic field, may have severe consequences for Earth in terms of climate, electricity grid systems and human behaviour.
If you were thinking that the only things we have to be concerned about include wars, famines and economic crashes, think again. Recent scientific discoveries are indicating that this next solar flare cycle could be powerful enough to disrupt our planet's entire electric grid. In this report I document a number of changes taking place with the Earth's magnetic field, the Sun and our solar system while explaining some of the concerns that today's leading scientists have voiced. I also examine how humankind may be affected energetically.
Our Planet's Magnetic Field
The magnetosphere is a bubble of magnetism that surrounds the Earth and protects us from solar wind. Fortunately, our planet's magnetic field diverts most particles into a circular path around the Earth. Like weather patterns found on Earth, solar wind patterns can change rapidly.
Luckily, our planet's magnetosphere quickly responds to the threat and absorbs the impact, wiggling and jiggling in the process. Geophysicists call this reaction a geomagnetic storm, but because of how it disrupts the Earth's magnetic field it could also be called electromagnetic pollution.
This is when we see the Aurora Borealis in our night skies.
But strange things are happening in both outer and inner space. The Earth's magnetic field has been weakening. This decrease actually began 2,000 years ago, but the rate of decrease suddenly became much more rapid 500 years ago. However, in the last 20 years or so, the magnetic field has become erratic.
Aeronautical maps of the world, which are used to allow aeroplanes to land using automatic pilot systems, have had to be revised globally in order for the autopilot systems to work.
Now, NASA's five THEMIS spacecraft have discovered a breach in the Earth's magnetic field that is 10 times larger than anything previously thought to exist. When this happens, solar wind can flow in through the opening to "load up" the magnetosphere for powerful geomagnetic storms.
Exploring the mystery is a key goal of the THEMIS mission, launched in February 2007.
The big discovery came on 3 June 2007, when the five probes serendipitously flew through the breach just as it was opening. Onboard sensors recorded a torrent of solar wind particles streaming into the magnetosphere, signaling an event of unexpected size and importance.
But the breach itself is not the biggest surprise. Researchers are even more amazed and baffled at the unexpected way it forms, overturning longheld ideas of space physics.
"At first I didn't believe it," said THEMIS project scientist David Sibeck of the Goddard Space Flight Center. "This finding fundamentally alters our understanding of the solar wind-magnetosphere interaction."
"The opening was huge—four times wider than Earth itself," said Wenhui Li, a space physicist at the University of New Hampshire, who has been analysing the data. Li's colleague Jimmy Raeder, also of the University of New Hampshire, said: "127 particles per second were flowing into the magnetosphere—that's a 1 followed by 27 zeros. This kind of influx is an order of magnitude greater than what we thought was possible."
Space physicists have long believed that holes in the Earth's magnetosphere open only in response to solar magnetic fields that point south. The great breach of June 2007, however, opened in response to a solar magnetic field that pointed north. To the layperson this may sound like a quibble, but to a space physicist it is almost seismic.
Unexpected Shield Drop
Regarding how our magnetic field is changing, what is understood today in the scientific community is that the solar wind presses against the Earth's magnetosphere almost directly above the equator, where our planet's magnetic field points north.
Scientists previously believed that if a bundle of solar magnetism came along and pointed north, too, the two fields should reinforce one another, strengthening the Earth's magnetic defences and slamming the door shut on the solar wind. In the language of space physics, a north-pointing solar magnetic field is called a "northern IMF" (interplanetary magnetic field) and it is synonymous with "shields up".
The big surprise is that when a northern IMF came along, the shields went down. This has completely overturned many scientists' understanding of things.
As researchers investigated the tear in the magnetic field, they discovered that 20 times more solar wind passed into the Earth's protective shield when the magnetic fields were aligned.
Northern IMF events don't actually trigger geomagnetic storms, Raeder noted, but they do set the stage for storms by loading the magnetosphere with plasma. A loaded magnetosphere is primed for auroras, power outages and other disturbances that can result when a CME (coronal mass ejection) hits.
This means that the impact of solar flares is 20 times as strong when the magnetic fields are aligned. The Earth's and the Sun's magnetic fields will be in sync at the peak of Solar Cycle 24, expected in 2012. This will cause an influx of solar particles. What the scientists didn't discuss is the impact on the human bioelectrical system.
Earth's Magnetic Field Changes Climate
The Earth's climate has been significantly affected by the planet's magnetic field, according to a Danish study published in January 2009 which could challenge the notion that human emissions are responsible for global warming.
"Our results show a strong correlation between the strength of the Earth's magnetic field and the amount of precipitation in the tropics," one of the two Danish geophysicists behind the study, Mads Faurschou Knudsen of the geology department at Aarhus University in Denmark, told Videnskab journal.
The results of the study (also published in the US scientific journal Geology) lend support to a controversial theory published a decade ago by Danish astrophysicist Henrik Svensmark, who claimed that the climate is highly influenced by galactic cosmic ray (GCR) particles penetrating the Earth's atmosphere.
Geomagnetic Field Reversal
Another recent study suggests that rapid changes in the churning movement of the Earth's liquid outer core are weakening the magnetic field in some regions of the planet's surface.
"What is so surprising is that rapid, almost sudden, changes take place in the Earth's magnetic field," said study co-author Nils Olsen, a geophysicist at the Danish National Space Center in Copenhagen. The findings suggest similarly quick changes are simultaneously occurring in the liquid metal, 1,900 miles (3,000 kilometres) below the surface, Olsen said. Fluctuations in the magnetic field have occurred in several far-flung regions of the Earth.
The changes "may suggest the possibility of an upcoming reversal of the geomagnetic field" said study co-author Mioara Mandea, a scientist at the German Research Centre for Geosciences in Potsdam. Earth's magnetic field has reversed hundreds of times over the past billion years, and the process could take thousands of years to complete.
The decline in the magnetic field is also opening the Earth's upper atmosphere to intense charged-particle radiation, according to scientists.
Cosmic Rays Slam the Earth
An international team of researchers has discovered a puzzling surplus of high-energy electrons bombarding Earth from space. The source of these cosmic rays is unknown, but it must be close to the solar system and could be made of dark matter. The results were reported in the 20 November 2008 issue of the journal Nature.
"This is a big discovery," said co-author John Wefel of Louisiana State University. "It's the first time we've seen a discrete source of accelerated cosmic rays standing out from the general galactic background." To study the most powerful and interesting cosmic rays, Wefel and colleagues spent the last eight years flying a series of balloons through the stratosphere over Antarctica. Their NASA-funded cosmic ray detector found a significant surplus of high-energy electrons.
"The source of these exotic electrons must be relatively close to the solar system—no more than a kiloparsec away," said co-author Jim Adams of the NASA Marshall Space Flight Center.
Galactic cosmic rays are subatomic particles accelerated to almost light- speed by distant supernovae explosions and other violent events. They swarm through the Milky Way, forming a haze of high energy particles that enter the solar system from all directions. Cosmic rays consist mostly of protons and heavier atomic nuclei with a dash of electrons and photons spicing the mix. Why must the source be nearby?
According to Adams: "High-energy electrons lose energy rapidly as they fly through the galaxy. They give up energy in two main ways: (1) when they collide with lower-energy photons, a process called inverse Compton scattering; and (2) when they radiate away some of their energy by spiralling through the galaxy's magnetic field." High-energy electrons are therefore local, but the researchers cannot pinpoint the source in the sky.
The Sun's Magnetic Field