How are auroras created

Aurora is a colorful luminous phenomenon that occurs when charged particles from the sun flow into the Earth's magnetic field, high above the Earth's north and south poles. They are called the Aurora australis at the South Pole and the Northern Lights at the North Pole.

Earth's auroras are caused by the excitation of molecules or atoms in the upper atmosphere by a stream of high-energy charged particles from the Earth's magnetosphere or the sun.

Auroras often appear in the latitudes near the magnetic poles of the sky, generally in a band, arc, curtain, radial shape, these shapes are sometimes stable and sometimes continuous changes. There are three conditions that create auroras: the atmosphere, magnetic fields, and high-energy charged particles. All three are indispensable.

Characteristics of aurora

The beauty of aurora

The aurora is regarded as one of the most beautiful wonders in nature. As early as 2,000 years ago, China began to observe the aurora and has a rich record of the aurora. The aurora is diverse, colorful, shaped, and beautiful, and there is no other phenomenon in nature that can match it.

It is difficult for any color pen to depict the dazzling light that plays impermanence and change in the cold bipolar air. Auroras sometimes appear for a very short time, like festive fireworks flash in the sky and disappear without a trace.

Sometimes they shine in the sky for hours; Sometimes like a ribbon, sometimes like a fire like a colorful giant screen, as if showing a ball screen movie, giving people the visual enjoyment of beauty.

People divide the aurora into five kinds according to its morphological characteristics: one is the arc with a neat and slightly curved base; The second is the auroral belt with curved and twisted floating bands; Third, the aurora is shaped like a cloud; The fourth is a veil like uniform curtain of auroral curtain; The fifth is a ray of extreme light along the direction of the magnetic field line.

The magical sounds of the aurora

The Aurora borealis is a luminous phenomenon that often appears in the upper atmosphere of the Earth at high latitudes, and is the result of the interaction of the solar wind and the Earth's magnetic field. The Northern lights are very beautiful, and accompanied by the northern lights, is a very mysterious sound.

The mysterious sounds of the Northern Lights have been the subject of many legends and have inspired fear and awe in the wilderness. The exact cause of the mysterious sounds of the Northern Lights is still a mystery, and the sounds do not always accompany the aurora.

From what has been recorded, it sounds like an indistinct crackle and tends to last only a short period of time. Others who have heard auroral sounds describe the sound as a crackling sound and feel that the sound is far away.

From these different descriptions, the scientists speculate that there may be several different principles behind the northern lights sound production.

How auroras form

Auroras are massive electrical discharges around the Earth. Charged particles from the Sun arrive near the Earth, and the Earth's magnetic field forces some of them to concentrate along the field lines to the north and south poles.

When they enter the upper atmosphere of the poles, they collide with and excite atoms and molecules in the atmosphere, producing light and forming auroras. The most common place is in two rings around latitude 67 degrees north and south. Fairban, Alaska, has more than 200 days a year of auroral phenomena, so it is known as the "Northern Aurora capital."

So auroras can only be seen at the Earth's north and south poles.

The magnetic field lines of the Earth's magnetosphere carry the energy of the solar wind into the Earth's interior, which drives the formation of the geomagnetic field. In addition to the Earth's internal electrical conductors, there is also a weak electrical conductor in the atmosphere's ionosphere.

When the solar wind is strong, the magnetic field line energy meets the magnetic reactance inside the Earth, and there is a lot of energy that cannot be consumed, so the aurora is formed in the ionosphere.