PS: Sunspots are temporary phenomena on the sun's photosphere that appear as darker spots than the surrounding area in visible light. Pen | fun | pavilion www. ｂｉｑｕｇｅ。 info They are caused by a high density of magnetic activity that inhibits the intense activity of the convection, creating an area of reduced temperature on the surface. Although their temperature is still about 3000-4500 K, they are clearly visible as black dots when compared to the surrounding 5,780 K, because the thermal intensity (i) of the black body (which is very similar to the black body) is proportional to the fourth power of the temperature (t). The activity cycle of sunspots is 11.2 years, and when they are active, they will have an impact on the earth's magnetic field, causing bad weather and cooling the climate. In severe cases, it can cause damage to all kinds of electronic products and electrical appliances.

ps: If you want to hear more of your voices and receive more of your suggestions, search for the WeChat public account "qdread" now and pay attention to it to give more support to "God Emperor of the Other World"!

Fourth, sunspots

Sunspots are temporary phenomena on the sun's photosphere that appear as darker spots than the surrounding area under visible light. They are caused by the intense activity of convection inhibited by a high density of magnetic activity, creating an area of reduced temperature on the surface. Although their temperature is still about 3000-4500 K, they are clearly visible as black dots when compared to the surrounding 5,780 K, because the thermal intensity (i) of the black body (which is very similar to the black body) is proportional to the fourth power of the temperature (t). The activity cycle of sunspots is 11.2 years, and they usually appear in groups, and when they are active, they will have an impact on the earth's magnetic field and cause bad weather. Cooler climate. In severe cases, it can cause damage to all kinds of electronic products and electrical appliances.

On the photosphere of the Sun, there are some swirling air currents. It resembles a shallow dish with a concave middle. Appearing black, these swirling currents are sunspots. The sunspot itself is not black, and the reason why it can be seen black is that its temperature is one or two thousand degrees lower than that of the light ball, and against the backdrop of the brighter light ball, it becomes a dark sunspot that looks like there is no bright light.

Sunspots are a type of solar activity that occurs in the photosphere of the sun, and it is the most basic and obvious activity phenomenon in solar activity. Sunspots are thought to be actually giant swirls of hot gas on the surface of the sun. The temperature is about 4,000 K (thermodynamic temperature scale units). Because the surface temperature of the photosphere is lower than that of the sun (the surface temperature of the photosphere is about 6,000 degrees Celsius), it looks like some dark spots. Sunspots rarely move alone. Often appears in groups.

Although sunspots are darker, they are as clear and conspicuous as solar flares when observed. Sunspots are not actually dark, but they appear to be black because the temperature of the vortex air flow is 4600C, which is more than 1400C lower than the normal temperature on the surface of the Sun. The size, number, position, and shape of sunspots are not fixed, they change over time. Astronomers refer to the year with the most sunspots as the "peak year of solar activity" and the year with the fewest sunspots as the "valley year of solar activity".

1. Basic characteristics

Sunspots Sunspots produce charged ions. It can destroy the ionosphere in the high altitude of the earth, cause anomalies in the atmosphere, and interfere with the earth's magnetic field, thus interrupting telecommunications. A fully developed sunspot is made up of a darker nucleus and a lighter part around it. The middle depression is about 500 kilometers. Sunspots often appear in pairs or groups, with the majority of them consisting of two main sunspots. The one located in the west is called the "leading sunspot", and the one located in the east is called the "following sunspot". A small black spot is about a thousand kilometers. And a big black can reach 200,000 kilometers.

The formation of sunspots is closely related to the sun's magnetic field. But exactly how he was formed, astronomers have not yet found a definite answer to this question. Scientists speculate, though. It is highly likely that a strong magnetic field has altered the structure of matter in a certain area, so that the light and heat inside the Sun cannot reach the surface efficiently. Such a "low temperature zone" was formed. The more sunspots may indicate that the sun is older (in recent years, it has been found that sunspots occupy half of the surface on red dwarfs), and it may also be a general feature of the lifetime of all stars, the periphery near sunspots should be warmer than the normal place of the sun (the reason for the difference in the length of the other), the movement of sunspots to low latitudes is due to the low density and rotation of the sun, just like the movement of the continental plate of the earth to low latitudes, the existence of depressions of 500 kilometers where there are sunspots may be the reason for the low temperature and no longer expanding.

2. Make an impact

The sun is the source of light and heat on the earth, and its every move will have a variety of effects on the earth. Since sunspots are a phenomenon of intense activity on the sun, the impact on the earth is obvious.

When there is a large group of sunspots on the sun, there will be a magnetic storm phenomenon that will cause the compass to shake and not indicate the direction correctly; Pigeons, who are usually very good at recognizing directions, will get lost; Radio communications can also be severely hampered, or even abruptly interrupted for a period of time, and these anomalies will pose a great threat to the safe navigation of aircraft, ships, and satellites, as well as television faxes, and so on.

Sunspots also cause changes in the Earth's climate. More than 100 years ago, a Swiss astronomer discovered that when there are many sunspots, the earth's climate is dry and agriculture is abundant; When there are few sunspots, the climate is humid and rainy. Zhu Kezhen, a well-known scientist in China, also found out that the centuries in which sunspots were recorded more in ancient Chinese books were also the centuries in which particularly cold winters appeared in China. Some people also counted the changes in rainfall in some areas, and found that this change is also repeated every 11 years, and it is likely that it is also related to the increase or decrease in the number of sunspots.

Scientists who study earthquakes have found that when the number of sunspots increases, there are more earthquakes on Earth. The number of earthquakes also varies from about 11 years to a cycle.

Botanists have also found that tree growth also varies with the 11-year cycle of solar activity. Trees grow faster in years with more sunspots; Years with few sunspots grow slowly.

What's even more interesting is that the change in the number of sunspots can even affect our body, and the change in the number of white blood cells in the human blood also has an 11-year cycle. And the average person in a year with fewer sunspots. The faster you feel hungry, the higher the yield of wheat. Wheat also has fewer aphids.

5. Magnetic storms

Severe geomagnetic disturbances on a global scale are known as magnetic storms. The so-called strong is relative to various geomagnetic disturbances. In fact, the change in the ground geomagnetic field is very small compared to its calm value. In the middle and low latitudes, the amount of variation in the terrestrial geomagnetic field rarely exceeds a few hundred nanometers (the tranquility value of the terrestrial geomagnetic field exceeds 30,000 nanometers in most parts of the world). General magnetic storms can only be detected by systematic observation by special instruments at the geomagnetic station.

Magnetic storms are a common occurrence. There are very few months when magnetic storms do not occur. When solar activity is enhanced, it may occur several times a month. Sometimes a magnetic storm occurs 27 days after (a solar rotation cycle) and then another magnetic storm. This type of magnetic storm is called a reproducible magnetic storm. The number of reproducibility is generally one or two times.

Magnetic storms and magnetospheric storms are different names for the same phenomenon that emphasize different aspects. Although the center of magnetic storms is in the magnetosphere, the traditional description of the morphology of magnetic storms is still represented by changes in the ground-based geomagnetic field. This is because the most well-understood representation of the terrestrial geomagnetic field is still the case.

During a magnetic storm, the magnetic declination and vertical components of the geomagnetic field fluctuate significantly, but the most characteristic is the horizontal component h. The process of magnetic storms is mostly represented by changes in the horizontal component. At the onset of most magnetic storms, there is a steep rise in the horizontal component on the magnetograms of most geomagnetic stations around the world. At mid- and low-latitude stations, the increase is about 10~20 nats. This is called a magnetic storm abrupt start and is denoted as SSC or SC. An abrupt start is a clear sign that identifies the occurrence of a magnetic storm. A magnetic storm with a rapid onset is called a magnetic storm with a rapid onset. The time when the emergency of the high latitude station occurs at the beginning of the low latitude station is ahead, and the time difference is not more than one minute.

The magnetic storm began to rush. The development is fast, the recovery is slow, and it usually lasts for two or three days before gradually returning to calm. After a magnetic storm, the magnetogram shows obvious fluctuations, which is also a sign of magnetic storm. The same magnetic storm behaves very differently on magnetographs at different latitudes and longitudes. In order to visualize the evolution of magnetic storms, magnetograms are usually averaged from several mid- and low-latitude stations at different longitudes around the world. The course of a magnetic storm after averaging is called a magnetic storm (the time at which the emergency starts) and is denoted as DST.

(1) Three stages

Magnetic storm variation can be broadly divided into three phases.

1. The first phase of the magnetic storm

Immediately after the onset of the magnetic storm, the horizontal component is larger than its calm value within a few hours. However, the magnitude of the increase is not large, generally tens of nanometers, and the magnetogram is relatively stable. This period is called the first phase of a magnetic storm.

2. The main phase of the magnetic storm

The horizontal component then quickly drops to a minimum. The descent time is about half a day, during which the magnetogram fluctuates violently. This is the period when magnetic storms are most active, known as the main phase of magnetic storms. Commonly referred to as magnetic storm amplitude or magnetic storm intensity. This is the absolute value of the difference between this minimum and the calm value, also known as the DST amplitude.

3. Magnetic storm recovery phase

The horizontal component drops to a minimum and then begins to rise. Calm returns after two or three days, a period called magnetic storm recovery.

(2) After-effects of magnetic storms

The overall effect of a magnetic storm is to reduce the terrestrial geomagnetic field. This effect lasts until two or three days after the recovery phase and is called the magnetic storm aftereffect. In general, the amplitude of a magnetic storm decreases with increasing latitude, indicating that the source of the main phase is closer to the equator.

During a magnetic storm, the most characteristic phenomenon in the magnetosphere is the increase in the number of current particles in the magnetospheric ring. In the magnetosphere, within the four earth radii above and below the magnetic equatorial plane, and within the area of two ~ ten earth radii from the center of the earth, there are protons with an energy of tens to hundreds of thousands of electron volts. These protons are called ring current particles, and they drift westward in the geomagnetic field to form a westward ring current, or magnetospheric ring current, with an intensity of about 1006 amperes. Magnetospheric ring currents are also present when the magnetosphere is calm. In the main phase of the magnetic storm, a large number of low-energy protons are injected into the ring current region from the magnetic tail plasma, which greatly increases the amplitude of the ring current. The magnetic effect of the enhanced ring current on the ground is the decrease of the h component. Each time a proton is injected, it causes H to drop once, which is called a substorm, and the main phase of a magnetic storm is the result of a series of substorms occurring continuously. The amplitude of the main phase of a magnetic storm is directly proportional to the total energy of the ring current particles. At a magnetic storm amplitude of 100 nanometers, the energies of the ring current particles can reach 4x1015 joules. This is about the total amount of energy that the magnetosphere gains from and dissipates from the solar wind in a typical magnetic storm. The total energy of the Earth's fundamental magnetic field outside the sphere with a radius of three Earth radii is only 3x1016 joules. It can be seen that the magnetospheric disturbance is intense during a magnetic storm.

During the magnetospheric substorm, the injected particles drift westward and orbit the Earth, and do not have time to drift into a closed loop of current during the main phase, so the ring current is always axially symmetrical, stronger on the twilight side.

In addition to the main phase loop current, the substorms that occur during the main phase of sunspots also correspond to the Berkeland current system. The Berkeland current system is obviously non-axisymmetric. It also produces magnetic effects at low and medium latitudes, but due to its distance, the effect is much weaker than in the aurora belt. It is combined with the geomagnetic effect of the non-axisymmetric part of the main phase loop current to form the DS field.

Due to the scattering effect of magnetospheric waves on the particles, as well as the charge exchange reaction of the particles, the ring current particles will disappear continuously. When the substorm stops, no more particles feed the ring current, and the ring current intensity begins to weaken and enters the magnetic storm recovery phase.

All these space currents, while generating a magnetic field on the ground, will also produce induced currents in the conductive crust and mantle, but the magnitude of the change in the geomagnetic field caused by the induced current is only half that of the change in the geomagnetic field caused by the space current. (The novel "God Emperor of the Other World" will have more fresh content on the official WeChat platform, and there will also be a 100% lottery gift for everyone!) Open WeChat now, click on the "+" sign in the upper right corner to "add friends", search for the official account "qdread" and follow, hurry up! (To be continued.) )

...

...