Radiation of the sun
The radio emission of the Sun has two components – constant and variable. During strong solar flares, the radio emission of the Sun increases by a factor of thousands or even millions of times compared with the radio emission of a calm Sun. X-rays come mainly from the upper atmosphere and the corona. Emission is especially strong during years of maximum solar activity. The sun emits not only light, heat and all other types of electromagnetic radiation. It is also a source of a constant stream of particles – corpuscles. Neutrinos, electrons, protons, alpha particles, as well as heavier atomic nuclei make up the corpuscular radiation of the Sun. A significant part of this radiation is a more or less continuous outflow of plasma – the solar wind, which is a continuation of the outer layers of the solar atmosphere – the solar corona. Against the background of this constantly blowing plasma wind, individual regions on the Sun are sources of more directed, amplified, so-called corpuscular streams. Most likely, they are associated with special regions of the solar corona — corona holes, and also, possibly, with long-lived active regions on the sun. Finally, the most powerful short-term fluxes of particles, mainly electrons and protons, are associated with solar flares. As a result of the most powerful flares, particles can acquire speeds that make up a significant fraction of the speed of light. A particle with such high energies is called solar cosmic rays. Solar corpuscular radiation has a strong effect on the Earth, and above all on the upper layers of its atmosphere and magnetic field, causing many interesting geophysical phenomena.
1c). Solar activity is a set of phenomena that periodically occur in the solar atmosphere. Manifestations of solar activity are closely related to the magnetic properties of solar plasma. The appearance of an active region begins with a gradual increase in magnetic flux in a certain region of the photosphere. In the corresponding places of the chromosphere after this, an increase in brightness in the lines of hydrogen and calcium is observed. Such areas are called flocculi. Approximately in the same areas on the Sun in the photosphere (i.e., somewhat deeper), an increase in brightness in white (visible) light is also observed — torches. The increase in energy released in the flare and floccula region is a consequence of the increased magnetic field strengths up to several tens. Then, in solar activity, sunspots are observed that occur 1-2 days after the appearance of the floccule in the form of small black dots – pores. Many of them soon disappear, and only individual pores turn into large dark formations in 2-3 days. A typical sunspot has dimensions of several tens of thousands of kilometers and consists of a dark central part – shadow and fibrous partial shade. The most important feature of spots is the presence of strong magnetic fields in them, reaching in the shadow region the greatest intensity of several thousand extreds. On the whole, the spot is a tube of magnetic field lines extending into the photosphere, which completely fill one or more cells of the chromospheric network. The upper part of the tube expands, and the lines of force in it diverge, like ears of corn in a sheaf. Therefore, around the shadow, magnetic lines of force take a direction close to horizontal. The total, total pressure in the spot includes the pressure of the magnetic field and is balanced by the pressure of the surrounding photosphere, so the gas pressure in the spot is lower than in the photosphere. The magnetic field seems to expand the spot from the inside. In addition, the magnetic field suppresses the convective motion of the gas, carrying energy from the depth up. As a result, the temperature in the region of the spot turns out to be less than about 1000 K. The spot, as it were, is cooled and chained by a magnetic field in the solar photosphere. Most of the spots arise in whole groups, in which, however, two large spots stand out. One, the largest, is in the west, and the other, slightly smaller, is in the east. There are often many small spots around and between them. This group of spots is called bipolar, because both large spots always have the opposite polarity of the magnetic field. They are, as it were, connected with the same magnetic field line tube, which emerged in the form of a giant loop from under the photosphere, leaving the ends somewhere in unobserved, deep layers. The spot that corresponds to the exit of the magnetic field from the photosphere has a northern polarity, and in the region of which the lines of force enter back under the photosphere, it has a southern polarity.
The most powerful manifestation of the photosphere is flash. They occur in relatively small regions of the chromosphere and corona located above groups of sunspots. At its core, a flash is an explosion caused by the sudden compression of the solar plasma. Compression occurs under the pressure of a magnetic field and leads to the formation of a long plasma bundle or tape. The length of such an formation is tens or even hundreds of thousands of kilometers.