41 thousand years ago.. What is the secret of the transition of the aurora borealis towards the equator?
The weak magnetosphere can be easily penetrated by the solar wind, leading to ozone layer damage, climate disruption, and extinction events.
The aurora borealis is defined as a mixture of colors that form at the north and south poles of the globe and is called the northern lights when it appears at the North Pole, and the Australian aurora when it appears at the south poles.
At the annual conference of the American Geophysical Union (AGU), which was held this month in “New Orleans” in the United States, a team of scientists reported that the disturbance of the Earth’s magnetic field that occurred approximately 41,000 years ago had pushed the aurora borealis towards the equator where it cannot be seen. Never, and that it took about 1,300 years for the magnetic field to regain its original strength and inclination.
The geomagnetic disturbance known as the “Laschamps event”, which occurred 41,000 years ago, resulted in a weakening of the magnetic north and south of the planet, causing the magnetic field to tilt on its axis in addition to losing a small part of its strength.
The Lachamp event is also called the Earth’s magnetic trip when the magnetic poles switch places for a brief period before returning to their original position again.
This event affected the magnetic tensile strength that usually directs the solar wind-borne solar particles towards the north and south poles, to interact with atmospheric gases and illuminate the night sky there.
According to a report published on the “Science Alret” website, Agnit Mukhopadiye, a doctoral student in the Department of Climate and Space Sciences at the University of Michigan, indicated that this period of intense geomagnetic change may also have shaped changes in the Earth’s atmosphere, And in turn, it affected the living conditions in parts of the planet.
The mineral drift near the center of the Earth, synchronized with the planet’s rotation, generates magnetic poles at the surface in the north and south. The magnetic field lines connect the poles in curved arcs that form what is known as the “magnetosphere”, which protects the planet from radioactive particles from space.
The magnetosphere also protects Earth’s atmosphere from erosion by the solar wind, or particles that come with the solar wind.
Earth’s magnetic disturbance
About 41,000 years ago, Mukhopadhyay says, the strength of the magnetosphere declined “to about 4% of modern values” off its original axis. “Several investigations in the past have predicted that the magnetosphere would disappear completely during the day.”
The researchers collected data on the planet’s magnetism from ancient rock deposits as well as volcanic data, to simulate the magnetic field during the Lachamp event. They combined this data in a simulation of the interactions of the magnetosphere with the solar wind, and then used these results in another model to calculate the location, shape and strength of the aurora borealis.
Mukhopadiye explains that it is the first time that scientists have used this technique to “simulate the geospace system and predict the formations of the magnetosphere, along with the location of the aurora borealis.”
They found that although the magnetosphere shrank to about 3.8 times Earth’s radius during the Lachamp event, it did not completely disappear. During this period, the poles that were previously located in the north and south moved towards equatorial latitudes, and the aurora borealis followed.
“The geomagnetic tilt was significantly deviated from the geographic poles, which led to the aurorae regions being pushed from the geographic polar regions of the Earth to latitudes in the direction of the equator,” Mukhopadiye noted.
The researcher and his team believe that prehistoric habitability on Earth was affected during the “Lachamp event” that caused an ecological crisis, a finding consistent with previous research as well.
Earlier this year, other researchers found that the weak magnetosphere can be easily penetrated by the solar wind, which leads to damage to the ozone layer, climate disruption and extinction events, and this may have contributed to the disappearance of “Neanderthals” in Europe as well, according to a report published In “Live Science” in February of this year.
Source : Science Alert + Live Science + Websites