Properties of space and time distribution of solar coronal holes

The space and time distribution properties of solar coronal holes (CH) are investigated. The data of the catalogue UAG-102, supplemented up to 1995, and synoptic H-charts of Solar Geophysical Data are used. It was found that both the polar and equatorial CH can be divided into two subclasses. The properties of time classes are discerned. Statistical weights of the recurrent CH are accounted, which allow to determine the character of rotation of the different classes of CH with more accuracy. It was shown that the equatorial CH with long lifetimes possess differential rotation that is similar to sunspot groups, and the long-living polar CH rotate as a rigid body. A conclusion about the existence of two types of large-scale solar magnetic fields is made.     

Active filaments as the main source of the solar wind plasma in the Earth’s orbit

The works on the relations of active filaments to geomagnetic disturbances, performed in 1953–1974 in the Geophysical Institute of Czechoslovakia [Bednarova-Novakova and Halenka, 1974], and to interplanetary MHD disturbances, performed in 1996–2006 in IZMIRAN by the author of this work with the collaborators, are briefly reviewed. The results of these works form the basis for the conclusion that the coronal-chromospheric plasma related to active filaments is the main source of plasma in the solar wind streams in the Earth’s orbit.     

Solar proton increases and dynamics of the electron outer radiation belt during solar events in December 2006

Increases in solar protons and variations in the electron and proton fluxes from the outer radiation belt are studied based on the GLONASS satellite measurements (the circular orbit at an altitude of ～20000 km with an inclination of ～65°) performed in December 2006. Indications in the channels, registered protons with energies of Ep = 3–70 MeV and electrons with energies of Ee > 0.04 and >0.8 MeV, are analyzed. The data on electrons with Ee = 0.8–1.2 MeV, measured on the Express-A3 geostationary satellite, are also presented. Before the strong magnetic storm of December 14 (|Dst|_max = 146 nT), the maximum of the outer belt electrons with the energy >0.7 MeV was observed at L ～ 4.5. After the storm, the fluxes of these electrons increased by more than an order of magnitude as compared to the prestorm level, and the maximum of a “new” belt shifted to L < 4 (minimal L reached by the GLONASS orbit). Under quiet geomagnetic conditions, solar protons with the energies >3 MeV fill only high-latitude legs of the GLONASS orbit. During the strong magnetic storm of December 15, the boundary of proton penetration into the magnetosphere almost merged with the orbital maximum of the proton radiation belt.     

The Influence of Atmospheric Fronts on Free and Forced Oscillations of the Water Level in the Sea of Azov

Doklady Earth Sciences - The influence of inhomogeneous moving atmospheric pressure fields on currents and free and forced oscillations of the level of the Sea of Azov, induced by constant wind, is...     

Spectrum and Variability of the Supernova Remnant G21.5-0.9

Measurements of the flux densities of the supernova remnant G21.5-0.9 at 4840 and 8450 MHz were performed in 2013–2018 on the 32-m telescope of the Svetloe Observatory of the Institute of Applied Astronomy, Russian Academy of Sciences. Multiple measurements revealed source variability. The flux densities of G21.5-0.9 for 1967–2010 from previously published data are used to compare the intensity of G21.5-0.9 and standard sources. An artificial-Moon flux scale is used to bring all the data into a single system and determine a refined spectrum. Analysis of the resulting data indicates that, first, the observed break in the source spectrum is not associated with energy losses of relativistic electrons due to synchrotron emission and, second, the source variability is manifest as flux-density changes described by one of two power-law dependencies for the flux versus frequency. The spectral indices of each of these dependencies have one of two constant values. Possible origins of the detected changes in the spectrum of G21.5-0.9 are discussed.

     

Ten-antenna prototype of a radio heliograph based on the Siberian Solar Radio Telescope

An upgrade of the Siberian Solar Radio Telescope (SSRT) [Smolkov et al., 1986; Grechnev et al., 2003] to a multiwave radio heliograph has been started. The radio heliograph being created will be designed mainly to measure coronal magnetic fields, to determine the locations of solar-flare energy release, and to investigate coronal mass ejections. These tasks define the parameters of next-generation radio heliographs. A high spatial resolution, a high image acquisition rate, and a high sensitivity are required simultaneously. All these parameters should be realized in the widest possible frequency range—from fractions to tens of GHz). The expected parameters of the future SSRT-based radio heliograph are listed below: spatial resolution 12″–24″, temporal resolution 0.02–1.0 s, frequency range 4–8 GHz, sensitivity up to 100 K, left-hand and right-hand circular polarizations, data rate 0.5–20 Mb s⁻¹ (normal and flare modes). In this paper, we describe the broadband antennas, analog optical data transmission lines, and correlator used in the 10-antenna radio heliograph prototype.     

The resource potential of Russian lands for crop farming

Geoinformational analysis shows that the fraction of lands that are optimal for farming of the main crops in Russia is about 10% of the available land at best (for summer wheat, buckwheat). For the majority of other crop cultures, this value is a few percent at most. The available resources are used very incompletely. The index of completeness of land resource potential use is no more than 10% for the majority of crops. Only in the case of soy are the available resources almost completely involved, whereas available land resources of winter wheat, grain maize, and sunflowers are used at 20–30%.