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Like most planets in our solar system, the Earth has its own magnetic field. Thanks to its largely melted iron core, our planet actually looks like a magnetic bar. It has a north and south magnetic pole, separated from the geographical poles, with a field connecting the two. This field protects our planet from radiation and is responsible for creating the north and south lights – spectacular events that are only visible near the magnetic poles.
However, with reports indicating that the magnetic north pole has begun to move rapidly at 31 miles per year – and may soon be over Siberia – it has long been unknown whether the northern lights will also move. Now, a new study, published in Geophysical Research Letters, came up with an answer.
Our planetary magnetic field has many advantages. For more than 2,000 years, travelers can use it to navigate the world. Some animals even seem to be able to find their way through the magnetic field. But more importantly, our geomagnetic field helps protect all life on Earth.
The Earth's magnetic field extends over hundreds of thousands of kilometers from the center of our planet, extending directly into interplanetary space, forming what scientists call a "magnetosphere". This magnetosphere helps to deflect solar radiation and cosmic rays, thus preventing the destruction of our atmosphere. . This protective magnetic bubble is not perfect, however, and some of the solar matter and energy can be transferred to our magnetosphere. Since it is then channeled into the poles by the field, it results in spectacular displays of the northern lights.
A roaming pole
The Earth's magnetic field is created by its molten iron core in motion, its poles are not fixed and they wander independently of each other. In fact, since its first official discovery in 1831, the North Magnetic Pole has traveled more than 1,200 miles from the Boothia Peninsula, in the far north of Canada, to the high Arctic seas. This wandering has generally been quite slow, about 9 km per year, which has allowed scientists to easily follow his position. But since the beginning of the century, this speed has increased to 31 miles a year. The south magnetic pole is also moving, but at a much slower pace (6 to 9 miles per year).
This rapid wandering of the north magnetic pole has caused problems for scientists and navigators. Computer models of the future location of the North Magnetic Pole have become seriously obsolete, making accurate navigation difficult with the aid of a compass. Although GPS works, it can sometimes be unreliable in the polar regions. In fact, the cluster is moving so fast that scientists charged with mapping the Earth's magnetic field have recently been forced to update their model much earlier than expected.
Will auroras move?
The auroras usually form an oval around the magnetic poles, and so if these poles move, it goes without saying that the auroras could too. With predictions suggesting that the north pole will soon be approaching northern Siberia, what effect could this have on the aurora?
Aurora borealis is currently mainly visible from northern Europe, Canada and the northern United States. If, however, they move north, across the geographical pole, following the north magnetic pole, this may well change. Instead, the northern lights would become more visible from Siberia and northern Russia and less visible from the much denser US-Canadian border.
Fortunately, for aurora hunters in the northern hemisphere, this may not be the case. A recent study has developed a computer model of Earth's aurora and magnetic poles from data dating back to 1965. It has shown that aurora, instead of following magnetic poles, follows the geomagnetic poles. There is only a small difference between these two types of poles, but it is an important difference.
Magnetic poles are the points on the Earth's surface where a compass needle points down or up, vertically. They are not necessarily connected and a line of demarcation between these points, across the Earth, would not necessarily cross its center. Therefore, in order to create better models over time, scientists assume that the Earth is like a right magnet at its center, creating exactly opposite poles – "antipodal". This means that if we draw a line between these points, the line would cross directly through the center of the Earth. At points where this line crosses the surface of the Earth, we have the geomagnetic poles.
The geomagnetic poles are a kind of reliable and averaged version of the magnetic poles, which move erratically all the time. Because of this, it turns out that they do not move as close as the magnetic North Pole. And since the dawn seems to follow the more average version of the magnetic field, it means that the aurora borealis do not move as fast. It seems that auroras stay where they are, at least for the moment.
We already know that the magnetic pole is moving. Both poles have wandered since the existence of the Earth. In fact, the poles are even reversed, the north becoming south and the south becoming north. These magnetic inversions occurred during the course of history, every 450,000 years or so. The last reversal took place 780 000 years ago, which means that we could have a reversal soon.
So be assured that a wandering pole, even fast, should not cause too many problems, with the exception of scientists who have the task of modeling it.
Nathan Case is an associate researcher in space and planetary physics at Lancaster University in the United Kingdom.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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