The beautiful aurora scenery we saw was taken in the suburbs of Huairou in Beijing, and was taken by a netizen named "Pushi". Yesterday, China's National Geographic Channel ** Weibo, and left a message saying that this is "the second aurora image record in Beijing's history". In fact, not only Beijing, but also geomagnetic storms caused by solar storms are bringing a wide range of aurora to some areas, which have been recorded in northern Heilongjiang, Hulunbuir in Inner Mongolia and other places. So, what is a geomagnetic storm?Auroras are rare in Beijing in the mid-latitudes, so is this geomagnetic storm very serious, and how will it affect our lives?
High-intensity aurora lights up the night sky of Mohe.
How beautiful is the picture?
Last night (December 1), there was an aurora in Arctic Village, Mohe City. Fuchsia and yellow-green aurora change colors, accompanied by bright stars dancing in the night sky.
It is understood that the occurrence of the aurora in the Daxinganling area of Heilongjiang is due to geomagnetic storm activity. In the middle and high latitudes of China, when the magnetic index is high, the aurora will erupt strongly. Mohe is the northernmost and highest latitude city in China, and it is also one of the best places to observe the aurora in China. Since the beginning of this year, there have been many aurora lights in Mohe. On the evening of December 1, in addition to Mohe, other cities in Heilongjiang Province also saw the beautiful scenery of the aurora.
What is a geomagnetic storm?
Why are there auroras?
A geomagnetic storm is a typical solar eruption activity. We know that the corona is the outermost layer of the solar atmosphere, when the sun erupts, there will be coronal mass ejections, a projectile can throw hundreds of millions of tons of solar materials away from the surface of the sun at a high speed of hundreds of thousands of meters per second, not only the kinetic energy of the huge mass and speed convergence, they also carry the sun's strong magnetic field energy, once it hits the earth, it will cause a change in the direction and size of the geomagnetic field, which is called a geomagnetic storm. There are many effects of geomagnetic storms, and the most intuitive one visible to the naked eye is the aurora, how is the aurora generated?Let's find out.
One of the many effects of magnetic storms is that they drive particles in the Earth's upper atmosphere to intensify, eventually causing the atmosphere to heat up and expand into higher space. The aurora, in fact, is only a "by-product" of geomagnetic storms, after the coronal material carries the energy of the sun and the earth meets, part of it will enter the poles with the earth's magnetic field, and collide with the atmosphere at a height of 100 to 400 kilometers from the ground, the process of impact is accompanied by energy exchange, these energy are absorbed by the extranuclear electrons of atmospheric atoms and molecules, and then quickly released, and the result of release is to produce luminescence. Green and red aurora come from oxygen atoms, while purple and blue aurora tend to come from nitrogen atoms.
Is it rare for aurora to occur in low and mid-latitude regions?
It is understood that 2024 is still an active year for the Sun. This means that at least this winter, the northern part of our country may still see the aurora. We know that the aurora can be observed at high latitudes, and Beijing is at about 40 degrees north latitude, so why can we also see the aurora?Is it rare for such auroras to occur in the mid-latitudes?Today, we also interviewed Zhu Jin, a researcher at the Beijing Planetarium, to hear his interpretation.
Why are the aurora seen in our country.
Mostly red?
Most of the aurora observed in our country are red, why is that?In fact, most of the aurora is concentrated in 90,400 kilometers above the Earth.
This is a schematic map of human observation of the aurora drawn by China National Geographic magazine, in which above 300 km, the aurora is mainly light red, 200 300 km is mainly dark red, 100 200 km is mainly green, and below 100 km is blue, purple or a mixture of colors. Because the surface of the earth has a certain curvature, the earth itself will block some distant objects. If the observation point is too far away from the aurora, you will only see the red aurora at a higher altitude. As a result, most of the aurora seen in China is red, while in the Arctic Circle, it is mostly green.
Why do we need to warn of geomagnetic storms?
Can the aurora be predicted?
The China Meteorological Administration also issued an early warning for this geomagnetic storm event. Previously, the National Space Weather Monitoring and Warning Center of the China Meteorological Administration issued a forecast that geomagnetic storms may occur on November 30, December 1 and December 2, among which, geomagnetic storms above moderate or even geomagnetic storms may occur on December 1. So, why the early warning?Does this mean that the aurora can also be predicted?
Experts say that when the solar coronal mass ejection or solar flare erupts, it will travel to the Earth at the speed of light, and humans will know about eight minutes after the occurrence of the above-mentioned solar activity. The Sun's stream of charged particles travels much slower, taking about two or three days to reach Earth, so humans can warn of possible geomagnetic storms.
For light chasers, the long-term forecast of the aurora is for reference only and is not entirely accurate, but the real-time "forecast" for 2 to 3 days in the short term is still worth believing.
In addition, Zhu Jin, a researcher at the Beijing Planetarium, also said that the impact of geomagnetic storms on the human body is very small and negligible, but it will have an impact on short-wave communications, but it will not last too long. In addition, geomagnetic storms may have an impact on the space station, the space station may be dragged by the atmosphere to cause the orbital altitude to drop, the error of satellite navigation equipment may also increase, and aviation flight will also face the dual risks of deterioration of the communication environment and radiation across the polar region, so advance forecasting can also prevent risks.
Edited by Chen Yanting.