Solar Activity. Solar activity and its impact on nature and climate

Solar activity monitoring and geomagnetic conditions Earth online according to various parameters... As well as maps of the Earth's ozone layer and earthquakes in the world over the past two days, weather and temperature maps.

X-ray radiation from the Sun

X-ray emission from the Sun shows a graph of solar flare activity. X-ray images show events on the Sun and are used here to track solar activity and solar flares. Large solar X-ray flares can alter the Earth's ionosphere, which blocks high-frequency (HF) radio transmissions to the sunlit side of the Earth.

Solar flares are also associated with Coronal Mass Ejections (CMEs), which can eventually lead to geomagnetic storms. SWPC sends space weather alerts at the M5 (5x10-5 W/MW) level. Some large flares are accompanied by strong radio bursts, which can interfere with other radio frequencies and cause problems for satellite communications and radio navigation (GPS).

Schumann resonances

Schumann resonance is the phenomenon of the formation of standing electromagnetic waves of low and ultra-low frequencies between the Earth's surface and the ionosphere.

The Earth and its ionosphere are a giant spherical resonator, the cavity of which is filled with a weakly electrically conductive medium. If an electromagnetic wave that arises in this environment, after circling the globe, again coincides with its own phase (enters resonance), then it can exist for a long time.

Schumann resonances

Having read Schumann's article on the resonant frequencies of the ionosphere in 1952, German doctor Herbert König drew attention to the coincidence of the main resonant frequency of the ionosphere of 7.83 Hz with the alpha wave range (7.5-13 Hz) of the human brain. He found it interesting and contacted Schumann. From that moment their joint research began. It turned out that other resonant frequencies of the ionosphere coincide with the main rhythms of the human brain. The idea arose that this coincidence was not a coincidence. That the ionosphere is a kind of master generator for the biorhythms of all life on the planet, a kind of conductor of the orchestra called life.

And, accordingly, the intensity and any changes in Schumann resonances affect the higher nervous activity man and his intellectual abilities, which was proven in the middle of the last century.

Proton index

Protons are the main source of energy in the Universe, generated by stars. They take part in thermonuclear reactions, in particular, pp-cycle reactions, which are the source of almost all the energy emitted by the Sun, come down to connecting four protons into a helium-4 nucleus, converting two protons into neutrons.

Proton flux

The electron and proton flux are taken from GOES-13 GOES Hp, GOES-13 and GOES-11. High-energy particles can reach Earth anywhere from 20 minutes to several hours after a solar event.

Components of magnetic field

GOES Hp is a minute chart containing averaged parallel components of the Earth's magnetic field in nano Teslas (nT). Measurements: GOES-13 and GOES-15.

Cosmic radiation

8-12 minutes after large and extreme solar flares, high-energy protons reach the Earth - > 10 MeV or they are also called solar cosmic rays(SKL). The flow of high energy protons entering the Earth's atmosphere is shown in this graph. A solar radiation storm can cause disturbances or breakdowns in spacecraft equipment and disable electronic equipment on Earth, lead to radiation exposure of astronauts, passengers and jet crews.

Geomagnetic disturbance of the Earth

An increase in the flow of solar radiation and the arrival of waves of solar coronal ejections cause strong fluctuations in the geomagnetic field - magnetic storms occur on Earth. The graph shows data from the GOES spacecraft; the level of geomagnetic field disturbance is calculated in real time.

Auroras

Auroras occur when the solar wind hits the upper layers of the Earth's atmosphere. Protons cause the diffuse Aurora phenomenon, which propagates along the Earth's magnetic field lines. Auroras are usually accompanied by a unique sound, reminiscent of a slight crackling sound, which has not yet been studied by scientists.

Electrons are excited by accelerating processes in the magnetosphere. The accelerated electrons propagate in the Earth's magnetic field in the polar regions, where they collide with atoms and molecules of oxygen and nitrogen in upper layers earth's atmosphere. In these collisions, electrons transfer their energy into the atmosphere, thus trapping atoms and molecules into higher energy states. When they relax back down to lower energy states, they
release energy in the form of light. This is similar to how a neon light bulb works. Auroras usually occur from 80 to 500 km above the earth's surface.

Ozone layer map

Temperature map

World weather

Earthquake map

The map shows earthquakes on the planet over the past 24 hours

The content of the article

SOLAR ACTIVITY. An active region on the Sun - (AO) - is a set of changing structural formations in a certain limited region of the solar atmosphere, associated with an increase in the magnetic field in it from values ​​of 10–20 to several (4–5) thousand oersteds. In visible light, the most noticeable structural formation of the active region is dark, sharply defined sunspots, often forming entire groups. Usually, among many more or less small spots, two large ones stand out, forming a bipolar group of spots with the opposite polarity of the magnetic field in them. Individual spots and the entire group are usually surrounded by bright openwork, mesh-like structures - torches. Here the magnetic fields reach values ​​of tens of oersteds. In white light, faculae are best visible at the edge of the solar disk, however, in strong spectral lines (especially hydrogen, ionized calcium and other elements), as well as in the far ultraviolet and x-ray regions of the spectrum, they are much brighter and occupy a larger area. The length of the active region reaches several hundred thousand kilometers, and its lifetime ranges from several days to several months. As a rule, they can be observed in almost all ranges of the solar electromagnetic spectrum from x-rays, ultraviolet and visible rays to infrared and radio waves. At the edge of the solar disk, when the active region is visible from the side, above it, in the solar corona, prominences are often observed in the emission lines - huge plasma “clouds” of bizarre shapes. From time to time, sudden explosions of plasma occur in the active region - solar flares. They generate powerful ionizing radiation (mainly X-rays) and penetrating radiation (energetic elementary particles, electrons and protons). High-speed corpuscular plasma flows change the structure of the solar corona. When the Earth falls into such a flow, its magnetosphere is deformed and a magnetic storm occurs. Ionizing radiation greatly affects conditions in the upper atmosphere and creates disturbances in the ionosphere. Possible influences on many other physical phenomena ( cm. section SOLAR-TERRESTRIAL RELATIONS).

First observations of sunspots.

Sometimes on the Sun, even with the naked eye, through smoked glass, you can see black dots - spots. These are the most noticeable formations in the outer, directly observable layers of the solar atmosphere. Reports of sunspots, sometimes observed through fog or smoke from fires, are found in ancient chronicles and annals. For example, the earliest mentions of “black places” on the Sun in the Nikon Chronicle date back to 1365 and 1371. The first telescopic observations were at the very beginning of the 17th century. were almost simultaneously carried out independently of each other by Galileo Galilei in Italy, Johann Holdsmith in Holland, Christopher Scheiner in Germany and Thomas Harriot in England. Under very good atmospheric conditions, in photographs of the Sun you can sometimes see not only the fine structure of sunspots, but also light openwork areas around them - torches, best visible at the edge of the solar disk. It is clear that, in contrast to an ideal emitter (for example, a white plaster ball, uniformly illuminated from all sides), the solar disk at the edge appears darker. This means that the Sun does not have a solid surface with the same brightness in all directions. The reason for the darkening of the solar disk towards the edge is the gaseous nature of its outer, cooling layers, in which the temperature, as in the deeper layers, continues to decrease outward. At the edge of the solar disk, the line of sight crosses the higher and colder layers of its atmosphere, which emit significantly less energy.

Galileo Galilei on sunspots.

Galileo was born in Pisa ( Northern Italy) in 1564. In 1609, he was one of the first to point his tiny telescope at the sky. Nowadays, every schoolchild can even make for himself from spectacle glass and an ordinary magnifying glass best tool. However, it is amazing how much new Galileo saw through his very imperfect telescope: the satellites of Jupiter, mountains and depressions on the Moon, the phases of Venus, spots on the Sun, stars in Milky Way and much more. Being an adherent of Copernicus' ideas about the central position of the Sun in our planetary system, he sought to confirm his ideas with observations. In 1632 Galileo published his famous book Dialogue about two world systems. In fact, this was the first popular science book written in a brilliant literary language, not in Latin, as was then customary among scientists, but in a language understandable to all compatriots of Galileo Italian. This book turned out to be a bold and risky support for the teachings of Copernicus, for which Galileo was soon brought to trial by the Inquisition. Naturally, Galileo hoped to use observations of the Sun as the most convincing argument. Therefore, in 1613 he published three letters in the form of beautiful engravings under the general title Descriptions and evidence related to sunspots. These letters were a response to the absurd arguments of Abbot Scheiner, who also observed sunspots, but mistook them for planets, which, in his opinion, were moving in the direction prescribed by the Ptolemaic system (geocentric), and therefore supposedly confirmed it. Galileo pointed out the mistake of Scheiner, who did not notice that his trumpet was inverting the image. He then proved that the spots belonged to the Sun, which turned out to be rotating. Galileo even made an assumption, which turned out to be correct, but which could only be proven two and a half centuries later, that the spots consist of gases colder and more transparent than the atmosphere of the Sun. Finally, having compared the blackness of the spots with the darkness of the sky beyond the edge of the image of the Sun and noticing that the Moon is darker than the background of the sky near the Sun, he established that sunspots are brighter than the brightest places on the Moon. This work by Galileo is the first serious scientific study devoted to the physical nature of the Sun. At the same time, this work is a brilliant example of fiction, illustrated with beautiful engravings by the author himself.

Observations of sunspots.

The total number of spots and the groups formed by them changes slowly over a certain period of time (cycle) from 8 to 15 years (on average 10–11 years). It is important that the presence of sunspots affects the Earth's magnetic field. This was noticed by Gorrebov back in the 18th century, and now it is already known that solar activity is associated with many terrestrial phenomena, so the study of solar-terrestrial connections is very important for practical life. Therefore, continuous and constant observations of the Sun are necessary, which are often hampered by bad weather and the insufficient network of special observatories. It is clear that even modest amateur observations, carried out carefully and well described (indicating time, place, etc.) can be useful for the international summary of solar activity data ( cm. Solar Geophysical data). In addition, observations made by an amateur in a given place may lead the observer to discover a new, previously unnoticed connection with some earthly phenomenon specific to that particular place. Every amateur can use his telescope to determine the most famous index of solar activity - the relative Wolff sunspot number (named after the German astronomer who introduced it in the mid-19th century). To determine the Wolf number, you need to count how many individual spots are visible in the image of the Sun, and then add to the resulting number ten times the number of groups that they form. Obviously, the result of such a calculation depends greatly on many factors, ranging from the size of the instrument, the quality of the image, which is greatly influenced by weather conditions, and ending with the skill and vigilance of the observer. Therefore, each observer must, based on a comparison of his long-term observations with generally accepted data, estimate the average coefficient by which he must multiply his estimates of Wolf numbers in order to obtain, on average, results on the generally accepted scale. A summary of generally accepted values ​​for Wolf numbers (W) can be found, for example, in the bulletin Solar Data, published by the Pulkovo Observatory in St. Petersburg.

Physical features of sunspots.

Sunspots and especially groups of sunspots are the most visible active formations in the solar photosphere. There are many known cases when large spots on the Sun were observed with the naked eye through smoked glass. Spots are always associated with the appearance of strong magnetic fields with strengths of up to several thousand oersteds in the solar active region. The magnetic field slows down the convective heat transfer, due to which the temperature of the photosphere at a shallow depth under the sunspot decreases by 1–2 thousand K. The spots originate in the form of many small pores, some of which soon die, and some grow into dark formations with a brightness of 10 times less than that of the surrounding photosphere. The shadow of a sunspot is surrounded by a penumbra formed by filaments radial to the center of the sunspot. The duration of existence of sunspots ranges from several hours and days to several months. Most sunspots form pairs elongated approximately along the solar equator - bipolar groups sunspots with opposite polarity of magnetic fields in the eastern and western members of the group. The number of sunspots and the bipolar groups formed by them changes cyclically (that is, over a variable time interval, on average close to 11 years) changing: first increasing relatively quickly, and then slowly decreasing.

Photospheric torches.

Around the sunspots there are often bright areas called torches from the Greek word torch(bun, torch). This is the initial phase of solar activity, best visible near the edge of the solar disk, where the contrast with the undisturbed background of the photosphere reaches 25–30%. The torches look like a collection of small bright points (torch granules hundreds of kilometers in size) forming chains and an openwork mesh. They are found in almost every active region on the Sun, and their appearance precedes the formation of sunspots. Outside active regions, faculae periodically appear in the polar regions of the Sun.

Floccules.

In the chromosphere above the plumes, their continuations are observed, having a similar structure and called flocculi (from the Latin flocculis- a small piece of fluff). This is a manifestation of solar activity in the chromosphere, clearly visible on the solar disk when observed in the spectral lines of hydrogen, helium, calcium and other elements.

Prominences and filaments.

Active formations in the solar corona - prominences - can reach the largest sizes. These are clouds of chromospheric material in the corona, supported by magnetic fields. They have a fibrous and ragged structure and consist of moving filaments and plasma clots, distinguished by an exceptional variety of shapes: sometimes they are like calm haystacks, sometimes they are swirling funnels reminiscent of chanterelle mushrooms or bushes, often these are figures of the most bizarre shapes. They also vary greatly in their dynamic features, ranging from quiet, long-lived formations to suddenly exploding eruptive prominences. The longest-lived, slowly changing quiet prominences are like curtains hanging almost vertically on magnetic field lines. When observed on the solar disk, such prominences are projected into long narrow filaments , which appear dark in images of the Sun in the red spectral line of hydrogen. This is explained by the fact that the substance of prominences absorbs photospheric radiation only from below, and scatters it in all directions.

Solar flares.

In a well-developed active region, a small volume of solar plasma sometimes suddenly explodes. This most powerful manifestation of solar activity is called a solar flare.

It occurs in the region of change in the polarity of the magnetic field, where strong oppositely directed magnetic fields “collide” in a small region of space, as a result of which their structure significantly changes. Typically a solar flare is characterized by rapid growth(up to ten minutes) and a slow decline (20–100 minutes). During a flare, radiation increases in almost all ranges of the electromagnetic spectrum. In the visible region of the spectrum, this increase is relatively small: for the most powerful flares, observed even in white light against the background of a bright photosphere, it is no more than one and a half to two times. But in the far ultraviolet and x-ray regions of the spectrum and, especially, in the radio range at meter waves, this increase is very large. Sometimes bursts of gamma rays are observed. Approximately half of the total energy of the flare is carried away by powerful emissions of plasma matter, which passes through the solar corona and reaches the Earth's orbit in the form of corpuscular streams interacting with the Earth's magnetosphere, sometimes leading to the appearance of auroras.

As a rule, flares are accompanied by the release of high-energy charged particles. If it is possible to detect protons during a flare, then such a flare is called a “proton flare.” Streams of energetic particles from proton flares pose a serious danger to the health and life of astronauts in outer space. They can cause malfunctions of on-board computers and other devices, as well as their degradation. The most powerful flares are visible even in “white light” against the background of a bright photosphere, but such events are very rare. For the first time such an outbreak was independently observed on September 1, 1859 in England by Carrington and Hodgson. The easiest way to observe solar flares is in the red line of hydrogen emitted by the chromosphere. In the radio range, the increase in radio brightness in active regions is so great that the total energy flux of radio waves coming from the entire Sun increases tens and even many thousands of times. These phenomena are called bursts of solar radio emission. Bursts appear at all wavelengths - from millimeter to kilometer. They are created by shock waves generated by the flare propagating in the solar corona. They are accompanied by streams of accelerated protons and electrons, causing plasma heating in the chromosphere and corona to temperatures of tens of millions of kelvins. The most likely source of energy released during a solar flare is thought to be a magnetic field. When the magnetic field strength increases in a certain region of the chromosphere or corona, a large amount of magnetic energy accumulates. In this case, unstable states can arise, leading to an almost instantaneous explosive process of energy release commensurate with the energy of billions nuclear explosions. The whole phenomenon lasts from several minutes to several tens of minutes, during which up to 10 25 –10 26 J (10 31–32 erg) are released in the form of an energetic ejection of plasma and a flow of solar cosmic rays, as well as electromagnetic radiation of all ranges - from X-rays and gamma rays - radiation up to meter radio waves. Hard ultraviolet and X-ray radiation from flares change the state of the Earth's atmosphere, causing magnetic disturbances that have a significant impact on the entire Earth's atmosphere, causing many geophysical, biological and other phenomena.

Solar cosmic rays

- a stream of charged particles of high energy, accelerated in the upper layers of the solar atmosphere, which arise during solar flares. They are detected near the Earth's surface in the form of sudden and sharp increases in the intensity of cosmic rays against the background of more highly energetic galactic cosmic rays . Observational upper limit on solar cosmic ray particle energy e To» 2·10 10 eV. The lower limit of their energy is uncertain and exceeds mega electron volts (e ToЈ 10 6 eV). During some flares it drops below 10 5 eV, i.e., essentially closes with the upper limit of the energy of solar wind particles. The conventionally accepted lower limit for the energy of solar cosmic rays is 10 5 – 10 6 eV. At lower energies, the particle flow acquires the properties of plasma , for which it is no longer possible to neglect the electromagnetic interaction of particles with each other and with the interplanetary magnetic field.

The main share of solar cosmic rays is made up of protons with e Toі 10 6 eV, there are also nuclei with a charge Z i 2 (up to 28 Ni nuclei) and energy e To from 0.1 to 100 MeV/nucleon, electrons with e Toі 30 keV (experimental limit). Noticeable fluxes of 2H deuterons were recorded, the presence of tritium 3H and the main isotopes C, O, Ne and Ar was established. During some flares, a noticeable amount of nuclei of the 3 He isotope appears. Relative content of nuclei with Zі 2 mainly reflects the composition of the solar atmosphere, while the fraction of protons varies from flare to flare.

A complex of phenomena (processes) preceding the moment t 0 generation of solar cosmic rays, as well as processes occurring near the moment t 0 (accompanying effects) and those accompanying the generation of solar cosmic rays (with a delay T relative to the moment t 0 or t 0 + D t, where D t– acceleration duration) is called a solar proton event (SPE). For particles with e Toі 10 8 eV The time dependence of the intensity of the flux of solar cosmic rays near the Earth (time profile of the SPE) has a characteristic asymmetrical appearance. It is depicted by a curve with a very rapid increase (over minutes and tens of minutes) with a slower decrease (from several hours to » 1 day). In this case, the amplitude of the increase on the Earth's surface can reach hundreds and thousands of percent relative to the background flux of galactic cosmic rays. As we move away from the Earth's surface (in the stratosphere, in satellite orbits, and in interplanetary space), the energy threshold for recording solar cosmic rays gradually decreases, and the frequency of observed proton events increases significantly. In this case, the time profile of the rays, as a rule, stretches over several tens of hours.

The distribution of solar cosmic rays by energy and charge near the Earth is determined by the mechanism of acceleration of particles in the source (solar flare), the characteristics of their exit from the acceleration region and the conditions of propagation in the interplanetary medium, therefore it is very difficult to reliably establish the shape of the spectrum of solar cosmic rays. Apparently, it is not the same in different energy intervals: in the representation of the differential energy spectrum by a power function ~ e-– g To g index decreases as the energy decreases) (the spectrum becomes flatter). In interplanetary magnetic fields, the spectrum noticeably transforms with time, and the value of g increases and the spectrum remains steeply falling, i.e. the number of particles decreases rapidly with increasing energy. The spectrum indicator in the source can vary from event to event within 2 Ј g Ј 5 depending on the power of the SPE and the energy interval under consideration, and for the Earth - accordingly within 2 Ј g Ј 7. Full number accelerated protons released into interplanetary space during a powerful SPE can exceed 10 32 , and their total energy is 10 31 erg, which is comparable to the energy of the electromagnetic radiation of the flare. The height at which particle acceleration occurs in the solar atmosphere appears to be different for different flares: in some cases, the acceleration region (source) is located in the corona, at a concentration of plasma particles P~ 10 11 cm –3 , in others – in the chromosphere, where P~ 10 13 cm –3 . The exit of solar cosmic rays beyond the solar atmosphere is significantly influenced by the configuration of magnetic fields in the corona.

Particle acceleration is closely related to the mechanism of occurrence and development of solar flares themselves. The main source of flare energy is the magnetic field. When it changes, electric fields arise, which accelerate charged particles. The most probable mechanisms of particle acceleration in flares are considered to be electromagnetic. Cosmic ray particles with charge Ze, mass At r and speed n in electromagnetic fields are usually characterized by magnetic rigidity R = Amp With n /Ze, Where A– atomic number of the element. When accelerated by a quasi-regular electric field that arises when the neutral current layer breaks in a flare, the process acceleration, all particles of hot plasma from the discontinuity region are involved, and a spectrum of solar cosmic rays of the form ~ exp ( –R/R 0), where R 0 – characteristic stiffness. If the magnetic field in the flare region changes regularly (for example, it grows over time according to a certain law), then the effect of betatron acceleration is possible. This mechanism leads to a power-law spectrum in rigidity (~ R – g). In the highly turbulent plasma of the solar atmosphere Irregularly changing electric and magnetic fields also arise, which lead to stochastic acceleration. The mechanism of statistical acceleration during collisions of particles with magnetic inhomogeneities (Fermi mechanism) has been developed in most detail. This mechanism gives an energy spectrum of the form ~ e – gk.

Under flare conditions, the main role should be played by fast (regular) acceleration mechanisms, although the theory also allows for an alternative possibility - slow (stochastic) acceleration. Due to the complexity of the physical picture of flares and the lack of accuracy of observations, it is difficult to choose between different mechanisms. At the same time, observations and theoretical analysis show that some combination of acceleration mechanisms may be at work in a flare. Fundamentally important information The processes of acceleration of solar cosmic rays can be obtained by recording the flux of neutrons and gamma radiation from flares, as well as from X-ray and radio electromagnetic radiation. Data on these radiations obtained using spacecraft indicate the rapid acceleration of solar cosmic rays (in seconds of time).

Leaving the acceleration region, particles of solar cosmic rays wander for many hours in the interplanetary magnetic field, scattering on its inhomogeneities, and gradually move to the periphery of the Solar system. Some of them invade the Earth's atmosphere, causing additional ionization of atmospheric gases (mainly in the region of the polar caps). Sufficiently intense fluxes of solar cosmic rays can significantly deplete the ozone layer of the atmosphere. Thus, solar cosmic rays play an active role in the system of solar-terrestrial connections. Powerful streams of fast particles during solar flares can create a serious danger in interplanetary space for spacecraft crews, their solar panels and electronic equipment. It has been established that the largest contribution to the total dose comes from solar protons with an energy of 2·10 7 – 5·10 8 eV. Particles of lower energies are effectively absorbed by the skin of spacecraft. Relatively small solar proton events create a maximum flux of protons with energy ec i 10 8 eV is not higher than 10 2 – 10 3 cm –2 s –1, which is comparable to the proton flux in the Earth’s internal radiation belt. Behind Lately one of the most powerful X17 flares occurred in September 2005. The values ​​of the maximum proton fluxes during powerful SPEs increase as the energy decreases. To ensure radiation safety of spacecraft, it is necessary to predict solar flares.

Cycle of solar activity.

The German amateur astronomer Heinrich Schwabe from Dessau, a pharmacist by profession, observed the Sun every clear day for a quarter of a century and noted the number of sunspots he noticed. When he was convinced that this number regularly increases and decreases, he published his observations in 1851 and thereby attracted the attention of scientists to his discovery. The director of the observatory in Zurich, R. Wolf, studied in detail the earlier data on the observation of sunspots and organized their further systematic registration. He introduced a special index to characterize the sun's sunspot activity, proportional to the sum of the number of all individual sunspots, in this moment observed on the solar disk, and ten times the number of groups formed by them. Subsequently, this index began to be called Wolf numbers. It turned out that the alternation of maxima and minima of the series of Wolf numbers does not occur strictly periodically, but at time intervals ranging from eight to fifteen years. However, in different eras the interval turned out to be the same, on average - about eleven years. Therefore, the phenomenon began to be called the 11-year cycle of solar activity.

At the beginning of the cycle, there are almost no sunspots at all. Then, over several years, their number increases to a certain maximum, after which somewhat more slowly it decreases again to a minimum. Taking into account the alternation of the magnetic polarity of the spots of bipolar groups and the entire Sun in neighboring cycles, the 22-year cycle of solar activity is physically more justified. There is evidence of the existence of longer cycles: 35-year (Brückner cycle), secular (80–130 years) and some others.

Solar activity indices.

The level of solar activity is usually characterized by special solar activity indices. The most famous of these are the Wolf numbers W, introduced by the German astronomer Rudolf Wolf: W = k(f + 10g), Where, f is the number of all individual spots currently observed on the solar disk, and g– tenfold the number of groups formed by them. This index successfully reflects the contribution to solar activity not only from the sunspots themselves, but also from the entire active region, mainly occupied by faculae. Therefore the numbers W agree very well with modern, more accurate indices, for example, the amount of radio emission flux from the entire Sun at a wave of 10.7 cm. There are also many other indices of solar activity, determined by the area of ​​faculae, flocculi, sunspot shadows, number of flares, etc.

The role of the Sun for life on Earth.

Different types of solar radiation determine the heat balance of land, ocean and atmosphere. Outside the earth's atmosphere, for every square meter of area perpendicular to the sun's rays, there is a little more than 1.3 kilowatts of energy. The Earth's land and waters absorb about half of this energy, and about one-fifth of it is absorbed in the atmosphere. The rest of the solar energy (about 30%) is reflected back into interplanetary space, mainly by the Earth's atmosphere. It is difficult to imagine what will happen if for some time some kind of barrier blocks the path of these rays to Earth. Arctic cold will quickly begin to grip our planet. In a week the tropics will be covered with snow. The rivers will freeze, the winds will subside and the ocean will freeze to the bottom. Winter will come suddenly and everywhere. Will begin heavy rain, but not from water, but from liquid air (mainly liquid nitrogen and oxygen). It will quickly freeze and cover the entire planet with a seven-meter layer. No life can survive in such conditions. Fortunately, all this cannot happen, at least suddenly and in the foreseeable future, but the picture described quite clearly illustrates the importance of the Sun for the Earth. Sunlight and heat were the most important factors in the emergence and development biological forms life on our planet. The energy of wind, waterfalls, river flows and oceans is the stored energy of the Sun. The same can be said about fossil fuels: coal, oil, gas. Under the influence of electromagnetic and corpuscular radiation from the Sun, air molecules disintegrate into individual atoms, which, in turn, are ionized. Charged upper layers of the earth's atmosphere are formed: the ionosphere and ozonosphere. They divert or absorb harmful ionizing and penetrating solar radiation, passing to the Earth's surface only that part of the Sun's energy that is useful to the living world, to which plants and living beings have adapted. However, even an insignificant residual part ultraviolet rays, reaching our beaches, can cause a lot of trouble for unwary tourists eager to get a tan.

Solar-terrestrial connections.

A complex of phenomena associated with the impact of solar corpuscular and electromagnetic radiation on geomagnetic, atmospheric, climatic, weather, biological and other geophysical and geological processes- the subject of a special discipline called solar-terrestrial connections. Its main ideas were laid down at the beginning of the 20th century. through the works of outstanding Russian scientists V.I. Vernadsky, K.E. Tsiolkovsky and A.L. Chizhevsky - the founder of heliobiology, an active researcher of the influence of solar activity on the most various phenomena happening on Earth.

The sun and the troposphere.

The Earth's surface heats up more than the air, so the surface air layers are warmer than the overlying ones. If you look at an open landscape on a hot day, you will notice rising jets of hot air. Thus, mixing (convection) occurs in the lower atmosphere of the Earth, similar to that which leads to the formation of granulation in the solar photosphere. This layer, 10–12 kilometers thick (in mid-latitudes), is called the troposphere. It is clearly visible from above from the window of an airplane flying over a veil of cumulus clouds - a manifestation of convection in the earth's atmosphere. The temperature in the troposphere steadily decreases with altitude, down to values ​​of –40 and even –80° C at altitudes of about 8 and 100 km.

Sun, weather and climate.

The influx of sunlight and heat into the rotating Earth leads to daily temperature changes at almost all latitudes, except at the polar ice caps, where nights and days can last up to six months. But what is most important here is the annual rhythm of solar irradiation, which is also noticeable throughout the Earth, except for the equatorial zone, where only the change of day and night is felt. Daily and annual changes in the Earth's exposure to solar rays lead to complex periodic variability in heating in different regions of the Earth. Uneven heating of different parts of the land, ocean and atmosphere leads to the emergence of powerful jet streams in the oceans, as well as winds, cyclones and hurricanes in the troposphere. These movements of matter smooth out temperature changes and at the same time have a strong influence on the weather at every point on the Earth and shape the climate on the entire planet. It can be expected that the thermal regime on Earth, established over thousands of years, should provide extremely accurate repeatability weather phenomena in each given region. In some places this is indeed the case. For example, since ancient history it has been known that the floods of the Nile, associated with precipitation in its upper reaches, begin like clockwork on the same day of the tropical year. However, in many other places, while the general patterns remain the same, noticeable deviations from the average are often observed. Many of them are reflected in calendars different nations, in particular in Russian (May is cold - the year is fertile, if on Evdokia a chicken can drink from a puddle, the summer will be warm, etc.). However, the dates, for example, of Epiphany and Vladimir frosts are more stable, and those of Christmas - less so. From geology we know about several ice ages. All these anomalies, at least partially, may be associated with solar activity.

Edward Kononovich

Literature:

Pikelner S.B. Sun. M., Fizmatgiz, 1961
Menzel D. Our sun. M., Fizmatgiz, 1963
Vitinsky Yu.I., Ol A.I., Sazonov B.I. The Sun and the Earth's Atmosphere. L., Gidrometeoizdat, 1976
Kononovich E.V. The sun is a day star. M., Education, 1982
Mitton S. Day star. M., Mir, 1984
Kononovich E.V., Moroz V.I. General astronomy course. M., URSS, 2001



Watch solar activity in real time: photo of the photosphere, magnetic field, transition layer, solar corona and solar wind, influence on the Earth.

SOHO Data

SDO/HMI data

LASCO coronagraph data

SOHO Data

EIT will provide large-scale images of the corona and transition region on the solar disk up to 1.5 solar radii. The optical system concentrates on spectral emission lines from Fe IX (171 Å), Fe XII (195 Å), Fe XV (284 Å) and He II (304 Å) to provide sensitive temperature analysis. Range: 6 × 10 4 K to 3 × 10 6 K

Image SOHO EIT 171

Image SOHO EIT 195

Image SOHO EIT 284

Image SOHO EIT 304

The telescope's field of view is 45 x 45 arc minutes and 2.6 arc seconds, which guarantees 5 times the spatial resolution. EIT intends to probe the coronal plasma globally, as well as the cool, turbulent atmospheric layer below. The data will form the basis for ground surveys.

SDO/HMI data

Solar Oscillation Investigation (SOI) uses the Doppler Shift Meter (MDI) to study the interior of the Sun by capturing photospheric stellar wobble events. Mode analysis displays the static and dynamic characteristics of the convection region and core. If we understand the properties, then let's understand better solar magnetic field and surface activity.

Image SDO/HMI Continuum

The instrument images the stars on a 10242 CCD camera through a string of narrow spectral filters. The final elements (a pair of interferometers) help MDI produce filtergrams with a FWHM bandwidth of 94 mA. Every minute, 20 frames are recorded at 5 wavelengths in the Ni I 6768 spectral line. The device determines the intensity and speed of the continuum with a resolution of 4’’ across the entire disk.

SDO/HMI Magnetogram Image

To ensure a constant view of the longest-lasting modes (displaying the internal solar structure), a set of spatial averages is carefully calculated. MDI spends half its time processing all downstream speeds and intensities of the image. High Speed ​​Telemetry (HRT) is available every year for 8 hours a day. During the 8-hour intervals, the HRT will be programmed to make other observations, such as higher resolution field calculations. Polarizers are inserted several times a day to change the line of sight of the magnetic field. MDI operations will be scheduled in advance and activated during daily 8-hour windows. Incoming data will be processed immediately. The data will go to the SOI Support Center (Stanford), where 3 terabytes of calibrated data are reviewed each year. Then the information will be posted for joint study.

LASCO coronagraph data

LASCO (wide-angle spectrometric coronagraph) was used by the SWPC office to analyze solar heating and transient events, including flares, corona and stellar wind. The resulting images are of great importance for the WSA-Enlil model, which began operating in 2011. It is the primary tool for predicting coronal mass release and the impact of solar wind on our planet.

Picture of LASCO C2

Picture of LASCO C3

LASCO is one of 11 instruments on NASA's SOHO (Solar and Heliospheric Observatory) spacecraft. It was launched in 1995 from the Kennedy Space Center. The instrument is represented by three coronagraphs displaying 1.1-32 solar radii. One radius covers 700,000 km. A coronagraph is a telescope that blocks light from the solar disk, allowing the faint radiation of the corona to be seen. The LASCO coronagraphs are part of the SOHO instrument suite, launched in 1995. SWPC used coronagraph images to forecast weather. The WSA-Enlil model is currently in effect.

The solar disk significantly influences planetary processes. After all, this is the main source of life. Therefore, solar activity attracts attention, as it leads to a transformation of the meteorological state of the Earth (pressure drops, water levels and temperature jumps) and human mental health. And watching magnetic storms online in real time is an unforgettable experience.

The Sun's atmosphere is dominated by a wonderful rhythm of ebb and flow of activity. the largest of which are visible even without a telescope, are areas of extremely strong magnetic field on the surface of the star. A typical mature spot is white and daisy-shaped. It consists of a dark central core called the umbra, which is a loop of magnetic flux extending vertically from below, and a lighter ring of fibers around it called the penumbra, in which the magnetic field extends outward horizontally.

Sunspots

At the beginning of the twentieth century. George Ellery Hale, using his new telescope to observe solar activity in real time, discovered that the spectrum of the spots was similar to that of cool red M-type stars. Thus, he showed that the shadow appears dark because its temperature is only about 3000 K, much less than the 5800 K of the surrounding photosphere. The magnetic and gas pressure in the spot should balance the surroundings. It must be cooled so that the internal pressure of the gas becomes significantly lower than the external one. Intense processes are taking place in “cool” areas. Sunspots cool due to the strong field's suppression of convection, which transfers heat from below. For this reason, the lower limit of their size is 500 km. Smaller spots are quickly heated by surrounding radiation and destroyed.

Despite the lack of convection, a lot of organized movement occurs in the sunspots, mainly in the penumbra, where horizontal field lines allow it. An example of such movement is the Evershed effect. This is a flow with a speed of 1 km/s in the outer half of the penumbra, which extends beyond its limits in the form of moving objects. The latter are elements of the magnetic field that flow outward through the area surrounding the sunspot. In the chromosphere above it, Evershed's reverse flow appears in the form of spirals. The inner half of the penumbra moves towards the shadow.

Vibrations also occur in sunspots. When a region of the photosphere known as the "light bridge" crosses the shadow, a fast horizontal flow is observed. Although the shadow field is too strong to allow motion, rapid oscillations with a period of 150 s occur just higher in the chromosphere. Above the penumbra the so-called traveling waves propagating radially outward with a period of 300 s.

Number of sunspots

Solar activity systematically passes over the entire surface of the star between 40° latitude, which indicates the global nature of this phenomenon. Despite significant fluctuations in the cycle, on the whole it is impressively regular, as evidenced by the well-established order in the numerical and latitudinal positions of the sunspots.

At the beginning of the period, the number of groups and their sizes quickly increase until after 2-3 years their maximum number is reached, and after another year the maximum area is reached. The average lifespan of a group is about one rotation of the Sun, but a small group may only last 1 day. The largest sunspot groups and largest eruptions usually occur 2 or 3 years after the sunspot limit is reached.

Up to 10 groups and 300 spots may appear, and one group can number up to 200. The course of the cycle may be irregular. Even near the maximum, the number of spots may temporarily decrease significantly.

11 year cycle

The number of spots returns to a minimum approximately every 11 years. At this time, there are several small similar formations on the Sun, usually at low latitudes, and for months they may be completely absent. New spots begin to appear at higher latitudes, between 25° and 40°, with a polarity opposite to the previous cycle.

At the same time, new spots can exist at high latitudes and old ones at low latitudes. The first spots of the new cycle are small and last only a few days. Because the rotation period is 27 days (longer at higher latitudes), they usually do not return, and newer ones end up closer to the equator.

For an 11-year cycle, the configuration of the magnetic polarity of groups of sunspots is the same in a given hemisphere and in the other hemisphere is turned towards opposite direction. It changes in the next period. Thus, new spots at high latitudes in the northern hemisphere may have a positive polarity followed by a negative one, while groups from the previous cycle at low latitudes will have the opposite orientation.

Gradually old spots disappear, and new ones appear in large quantities and sizes at lower latitudes. Their distribution is butterfly shaped.

Full cycle

Since the configuration of the magnetic polarity of sunspot groups changes every 11 years, it returns to the same value every 22 years, and this period is considered the period of a complete magnetic cycle. At the beginning of each period, the general field of the Sun, determined by the dominant field at the pole, has the same polarity as the spots of the previous one. As the active regions rupture, the magnetic flux is divided into sections with a positive and negative sign. After many spots have appeared and disappeared in the same zone, large unipolar regions with one sign or another are formed, which move towards the corresponding pole of the Sun. During each minimum at the poles, the flow of the next polarity in that hemisphere predominates, and this is the field visible from Earth.

But if all magnetic fields are balanced, how are they divided into large unipolar regions that control the polar field? No answer has been found to this question. Fields approaching the poles rotate more slowly than sunspots in the equatorial region. In the end weak fields reach the pole and reverse the dominant field. This changes the polarity that the leading spots of the new groups must take, thus continuing the 22-year cycle.

Historical evidence

Although the solar activity cycle has been fairly regular for several centuries, significant variations have also been observed. In 1955-1970 much more spots was in the northern hemisphere, and in 1990 they dominated the southern. The two cycles that peaked in 1946 and 1957 were the largest in history.

English astronomer Walter Maunder found evidence of a period of low solar magnetic activity, pointing out that between 1645 and 1715 very few sunspots were observed. Although the phenomenon was first discovered around 1600, few sightings were recorded during this period. This period is called the Mound minimum.

Experienced observers have reported the appearance new group spots as a great event, noting that they had not seen them for many years. After 1715 this phenomenon returned. It coincided with the coldest period in Europe from 1500 to 1850. However, the connection between these phenomena has never been proven.

There is some evidence of other similar periods at intervals of about 500 years. When solar activity is high, strong magnetic fields generated by the solar wind block high-energy galactic cosmic rays approaching Earth, leading to less carbon-14 production. Measuring 14 C in tree rings confirms low solar activity. The 11-year cycle was not discovered until the 1840s, so observations were sporadic before that time.

Ephemeral Areas

In addition to sunspots, there are many tiny dipoles called ephemeral active regions, which last less than a day on average and are found throughout the Sun. Their number reaches 600 per day. Although ephemeral regions are small, they can make up a significant part of the star's magnetic flux. But since they are neutral and quite small, they probably do not play a role in the evolution of the cycle and the global field model.

Prominences

This is one of the most beautiful phenomena that can be observed during solar activity. They are similar to clouds in the Earth's atmosphere, but are supported by magnetic fields rather than heat currents.

Plasma of ions and electrons, component solar atmosphere, cannot cross horizontal field lines, despite the force of gravity. Prominences appear at the boundaries between opposite polarities, where field lines change direction. Thus, they are reliable indicators of abrupt field transitions.

As in the chromosphere, prominences are transparent in white light and, with the exception of total eclipses, should be observed in Hα (656.28 nm). During an eclipse, the red Hα line gives the prominences a beautiful pink hue. Their density is much lower than that of the photosphere because there are too few collisions to generate radiation. They absorb radiation from below and radiate it in all directions.

The light visible from Earth during an eclipse is devoid of upward rays, causing the prominences to appear darker. But since the sky is even darker, they appear bright against its background. Their temperature is 5000-50000 K.

Types of prominences

There are two main types of prominences: quiet and transitional. The former are associated with large-scale magnetic fields that mark the boundaries of unipolar magnetic regions or groups of sunspots. Since such areas live for a long time, the same is true for quiet prominences. They may have different shape- hedges, suspended clouds or funnels, but always two-dimensional. Stable filaments often become unstable and erupt, but can also simply disappear. Quiet prominences live for several days, but new ones can form at the magnetic boundary.

Transient prominences are an integral part of solar activity. These include jets, which are a disorganized mass of material ejected by the flash, and clumps, which are collimated streams of small emissions. In both cases, part of the substance returns to the surface.

Loop-shaped prominences are the consequences of these phenomena. During the flare, the flow of electrons heats the surface to millions of degrees, forming hot (more than 10 million K) coronal prominences. They radiate strongly as they cool and, unsupported, descend to the surface in elegant loops following magnetic lines of force.

Flashes

The most spectacular phenomenon associated with solar activity are flares, which are a sharp release of magnetic energy from the sunspot region. Despite their high energy, most are almost invisible in the visible frequency range because energy emission occurs in a transparent atmosphere and only the photosphere, which reaches relatively small energy levels, can be observed in visible light.

The flares are best seen in the Hα line, where the brightness can be 10 times greater than in the neighboring chromosphere and 3 times greater than in the surrounding continuum. In Hα, a large flare will cover several thousand solar disks, but only a few small bright spots appear in visible light. The energy released in this case can reach 10 33 erg, which is equal to the output of the entire star in 0.25 s. Most of this energy is initially released in the form of high-energy electrons and protons, with visible radiation being a secondary effect caused by the particles impacting the chromosphere.

Types of flares

The range of flare sizes is wide - from gigantic ones, bombarding the Earth with particles, to barely noticeable ones. They are usually classified by their associated X-ray fluxes with wavelengths from 1 to 8 angstroms: Cn, Mn or Xn for greater than 10 -6 , 10 -5 and 10 -4 W/m 2 , respectively. Thus, M3 on Earth corresponds to a flux of 3 × 10 -5 W/m 2. This indicator is not linear as it only measures the peak and not the total radiation. The energy released in the 3-4 largest flares each year is equivalent to the sum of the energies of all the others.

The types of particles created by the flares change depending on where the acceleration occurs. There is not enough material between the Sun and Earth for ionizing collisions, so they retain their original ionized state. Particles accelerated in the corona by shock waves exhibit a typical coronal ionization of 2 million K. Particles accelerated in the flare body have significantly higher ionization and extremely high concentrations of He 3, a rare isotope of helium with only one neutron.

Most major outbreaks occur in small quantity superactive large groups of sunspots. Groups are large clusters of one magnetic polarity surrounded by the opposite one. Although predicting solar flare activity is possible due to the presence of such formations, researchers cannot predict when they will appear and do not know what produces them.

Impact on Earth

In addition to providing light and heat, the Sun affects the Earth through ultraviolet radiation, the constant flow of solar wind, and particles from large flares. Ultraviolet radiation creates ozone layer, which in turn protects the planet.

Soft (long-wave) X-rays create the layers of the ionosphere that make short-wave radio communications possible. During days of solar activity, the radiation from the corona (slowly varying) and flares (impulsive) increases, creating a better reflective layer, but the density of the ionosphere increases until radio waves are absorbed and shortwave communication is difficult.

The harder (shorter wavelength) X-ray pulses from the flares ionize the lowest layer of the ionosphere (the D-layer), creating radio emission.

The Earth's rotating magnetic field is strong enough to block the solar wind, forming a magnetosphere with particles and fields flowing around it. On the side opposite the star, the field lines form a structure called a geomagnetic plume or tail. When the solar wind intensifies, there is a sharp increase in the Earth's field. When the interplanetary field switches in the opposite direction to Earth's, or when large clouds of particles hit it, the magnetic fields in the plume reconnect and energy is released, creating auroras.

Magnetic storms and solar activity

Each time a large one approaches the Earth, the solar wind accelerates and occurs. This creates a 27-day cycle, especially noticeable at sunspot minimum, which makes it possible to predict solar activity. Large flares and other events cause coronal mass ejections, clouds of energetic particles that form a ring current around the magnetosphere, causing sharp fluctuations in the Earth's field called geomagnetic storms. These phenomena disrupt radio communications and create voltage surges on long-distance lines and other long conductors.

Perhaps the most intriguing of all terrestrial phenomena is the possible influence of solar activity on our planet's climate. The Mound minimum seems reasonable, but there are other clear effects. Most scientists believe there is an important connection masked by a number of other phenomena.

Because charged particles follow magnetic fields, corpuscular emission is not observed in all large flares, but only in those located in the western hemisphere of the Sun. The lines of force on its western side reach the Earth, sending particles there. The latter are mainly protons, because hydrogen is the dominant constituent element of the sun. Many particles, moving at a speed of 1000 km/s second, create a front shock wave. The flow of low-energy particles in large flares is so intense that it threatens the lives of astronauts outside the Earth's magnetic field.

On this page you can very well monitor our space weather, which is primarily determined by the Sun. Data is updated very often - almost every every 5-10 minutes , so you can always, by visiting this page, know the exact state of affairs in the field of activity of our Sun and space weather.

• Thanks to this page and its online data, you can quite accurately understand the state of space weather and its impact on Earth at the current moment in time. Graphs and maps are posted (online from specialized online servers that collect and process data from satellites) describing space weather (which is convenient for tracking anomalies).

Now you can see The sun online in animation mode, in order to visually better observe all changes in the Sun, such as flares, objects flying nearby, etc.:

The state of space weather in our system depends primarily on the current state of the Sun. Hard radiation and flares, streams of ionized plasma, solar wind originating in the Sun are the main parameters. Hard radiation and flares depend on so-called sunspots. Maps of spots and radiation distribution in X-rays are visible below (this is a photo of the sun taken today: March 18, Monday).

(18.03.2019) Sunrise: 06:37, sun at zenith: 12:38, sunset: 18:39, day length: 12:02, morning twilight: 06:00, evening twilight: 19:16, .

Coronal transient ejections and nascent solar wind streams marked in the figure below (this is a photo of the Sun’s corona taken today: March 18, Monday).

Solar flare schedule. Using this graph, you can find out the strength of the flares that occur on the Sun every day. Conventionally, flares are divided into three classes: C, M, X, this can be seen on the scale of the graph below, the peak value of the red line wave determines the strength of the flare. The most strong flash- class X.

World Temperature Map

World weather high temperatures can be followed on the frequently updated map below. Recently, a shift in climate zones has been clearly visible.

Sun now (March 18, Monday) in the ultraviolet spectrum(in one of the most convenient for viewing the state of the Sun and its surface).

Stereo image of the Sun. As you know, two satellites were recently specially sent into space, which entered a special orbit in order to “see” the Sun from two sides at once (previously we saw the Sun only from one side) and transmit these images to Earth. Below you can see this image, which is updated daily.

[photo from the first satellite]

[photo from the second satellite]