Aurora erupts in Beijing, and there may be more tomorrow morning! Why does this astronomical wonder happen?

In the early morning of October 11, affected by the geomagnetic storm, auroras were seen again in many places in Beijing.

Beijing Labagou witnessed a massive aurora explosion, with the northern sky turning red visible to the naked eye.

Photographed by: Jing Decai

In addition, Beijing Daily photographers also captured the shining aurora at the Jinshanling Great Wall in Luanping County, Chengde City, Hebei Province, which is near Beijing.

Photographed by: Zhou Wanping

At the Hebei section of the Jinshanling Great Wall at the border between Beijing and Hebei, the ancient Great Wall looks spectacular against the backdrop of the starry sky and the aurora.

Looking from Beijing Lingshan Scenic Area, the city lights and the aurora in the direction of Huailai complement each other.

It is reported that this is the second time that the aurora can be observed at 40° north latitude in my country. The last time was around May 11 this year.

Previously, the National Space Weather Monitoring and Early Warning Center introduced that from 8:00 on October 8 to 8:00 on October 10, Beijing time, the sun experienced five explosive activities. The strongest were the X2.1 flare that erupted in solar active area 13842 at around 3:12 on October 8, and the X1.8 flare that erupted in active area 13848 at 9:56 on October 9, both reaching the level of large flares.

Since the first eruption of the sun on October 9 happened to be facing the earth, and there was a lot of energy and matter and the propagation speed was fast, strong geomagnetic activities may occur in the following days. A large geomagnetic storm may occur from the evening of the 10th to the evening of the 11th. If there is no new eruption activity, a small to moderate geomagnetic storm may occur on the 12th, and then gradually return to calm.

Starting from the evening of October 10, especially from the early morning of October 11 to the early morning of October 12, there is a chance that relatively obvious auroras will appear in northern my country, and in some areas there is even the possibility of red and green composite auroras.

There are currently two main indices for measuring geomagnetic storms: Dst and Kp. Generally speaking, Dst <-30 nT or Kp reaches 5, which means a small geomagnetic storm; Dst <-100 nT or Kp reaches 7, which means a large geomagnetic storm; and Dst <-200 nT or Kp reaches 8, which means an extremely large geomagnetic storm.

Aurora forecast for the next three days. (Source: Aurora Forecast App)

Current situation of active regions (sunspots) on the solar surface.

Not only in Beijing, but also in Mohe, Heilongjiang, auroras have recently appeared due to the influence of geomagnetic storms. According to CCTV News, auroras appeared in Mohe City, Daxing'anling Region, Heilongjiang Province from the evening of October 7 to the early morning of October 8. Over the Arctic Village in Mohe City, red, green, and purple auroras danced in the night sky, which was very shocking.

Mohe is the northernmost and highest-latitude city in China. It is also one of the best places to observe the aurora in the country. Every year, many photography enthusiasts come here to chase the aurora. Since 2024, the aurora has appeared many times in Mohe City.

The aurora was photographed in Jixiang Township, Tangyuan County, Jiamusi City, Heilongjiang Province in the early morning of October 8. Xinhua News Agency

What exactly are the Aurora?

The aurora is a colorful plasma phenomenon that occurs when the flow of charged particles from the sun (solar wind) enters the Earth's magnetic field, and the brilliant and beautiful light appears at night in the high altitudes near the Earth's North and South Poles. In the South Pole, it is called the Southern Lights, and in the North Pole, it is called the Northern Lights. The Earth's aurora is produced by the high-energy charged particle flow (solar wind) from the Earth's magnetosphere or the sun, which excites (or ionizes) molecules or atoms in the upper atmosphere.

Most auroras appear between 90 and 130 kilometers above the Earth. In 1959, one auroras display was measured at an altitude of 160 kilometers and a width of more than 4,800 kilometers. But some auroras are much higher, reaching altitudes of 560 to 1,000 kilometers or more.

Due to the effect of the geomagnetic field, these high-energy particles turn to the polar regions, so auroras are common in high magnetic latitudes. Auroras often appear in the range of about 25° to 30° from the magnetic poles, and this area is called the auroral zone. The geomagnetic latitude range of 60°-90° is called the auroral zone, the area between 45°-60° is called the weak auroral zone, and the area below 45° is called the micro auroral zone.

Why are geomagnetic storms occurring so frequently this year?

Solar flare activity shows a cyclical variation of about 11 years. The 25th solar activity cycle began in 2019 and is currently entering its peak year. Experts say that this year and next year will be high seasons for solar activity, and there may be some space weather events such as strong solar flares and geomagnetic storms in the future, which are normal natural phenomena. Geomagnetic storms have little impact on human health and daily life.

For pigeon players who are participating in the autumn racing, they should try to avoid releasing or racing during geomagnetic storms. They should also pay close attention to regular weather forecasts to reduce unnecessary pigeon losses.

Where can I see the Northern Lights in Beijing?

To photograph the aurora, you need to stay away from light pollution areas and head due north. Netizens have recorded the aurora phenomenon many times in Huairou, Mentougou, and Yanqing, Beijing. The places where photography enthusiasts often shoot are Mutianyu, Baihewan, Labagoumen, etc.

How to take good photos of the Aurora?

Things to note when photographing the Aurora:

To photograph the aurora, you need to stay away from light-polluted areas and usually need to climb mountains at night, so be sure to pay attention to safety!

The brightness of the aurora is similar to that of moonlight, slightly brighter than starlight. You can refer to the exposure parameters of moonlight. At the same time, the sensitivity should be increased and the white balance needs to select a fixed value.

When photographing the aurora, the autofocus will fail. You can use the screen to frame the shot, focus manually, and use a tripod.

Find the right direction and make sure there are no large obstructions to the north.

Source: Beijing Evening News WeChat Official Account, Beijing Daily, CCTV News, Space Weather, Guangxi Normal University School of Physics Science and Technology WeChat Official Account