Search academic texts

Information × Registration Number 0210U001462, 0107U000674 , R & D reports Title Astrophysical investigations and monitoring of the Sun, Jupiter and the Moon on data of earthbased and space observations popup.stage_title Head Korokhin Viktor, Registration Date 17-02-2010 Organization Kharkov National University named after V.N. Karazin popup.description2 Objects of the investigations are the solar corona and chromosphere, the lunar surface and Jovian atmosphere. Goal of the work is monitoring of solar activity, studying of physical properties of the solar corona and chromosphere, atmospheres and surfaces of planets. Methods of investigation are spectrometrical, photometrical and polarimetrical, using theoretical analysis of data, theoretical and digital modeling the processes of light scattering on planets surfaces and in atmospheres. It is concluded that most of the quasi-synchronous events of March 3 - 4, 2002, were generated by simultaneous emergence of the new magnetic flows in the photosphere which was conditional on the evolution of great equatorial coronal hole (CH). Series of daily solar indices of sunspot numbers W (1900 -2008), solar flux at 2800 MHz F10.7 (1947 - 2008) and numbers of X-ray flares Nx (1981 - 2008) were studied. Methods of Fourier analysis and of wavelet analysis were used for detection of ~ 156 day quasi-periodicity (called as Rieger Type Periodicities, RTP). We have found that the significant amplitude of RTP for W existed near of solar maxima except 14, 15 and 23 cycle's maxima. The largest power of 156 -day peak was observed at the declining phase of cycle 16, at maximum of cycle 21 and at the increasing phase of cycles 20 and 23. The significant RTP was observed at the minima of 17, 18 and 19 cycles too. We drew the conclusion that the dependence RTP from the phase of solar cycles is absent. Dependencies of solar indices values on orbital positions of Mercury, Venus, and Earth were studied by the method of superpose epochs. The statistically significant asymmetry in the distribution of Nx on the heliographic longitude of the planets is revealed. Dependencies of solar indices W and F10.7 on orbital positions of Mercury and Venus are statistically significant too. The statistically significant seasonal variations of these indices on orbital position of Earth are not found. On the basis of the polarimetric data the study of physical processes in upper atmosphere and in magnetosphere of Jupiter, caused by solar radiation and the solar activity, was carried out. It is noted the influence of solar cosmic rays on forming of polarization. Computer modeling of light scattering in Jupiter's atmosphere using Monte-Carlo method has been carried out. Studying the affect of non-spherical shape of aerosols on results of modeling shows that scattering on aerosol layer which consist of spheroids with relation of semiaxes from 0.4 to 3.6 results in similar values of polarization. Calculated latitudinal dependencies of linear polarizations for haze which consist of such particles have qualitative accordance with observations. An algorithm and software for mapping the parameters of phase function with taking into account relief of the surface have been developed. This algorithm allows to release practically fully the maps of these parameters from influence of relief and allow to construct map of zonal components of relief slopes. An algorithm for correction of photometric observations for the relief influence has been developed. It allows to study phase dependence of brightness of lunar surface not only for flat marine regions but also for highlands and other areas with the expressed topography. Comparison of data of topography of the Moon retrieved from photometric observations with data of laser altimeter LALT of spacecraft Kaguya (Selene) has been carried out. The comparison shows, that both the maps demonstrates very similar distribution of zonal slopes over the lunar disk. However, our map shows a residual influence of albedo, and the LALT map contains many artifacts. Thus, the considered version of the LALT map should be used with caution. Our map can be used for an independent control of the LALT data. Algorithm of modeling the light scattering in multicomponent mediums using Monte-Carlo method has been realized on C++ programming language. It allow to make calculations not only by the personal computers but also computers of practically any architecture. Due to new realization the speed of work of the program was considerably increased (in 10-20 times), computer's memory using was decreased (approximately in 20 times) and distributed calculations have been added. Modeling of light scattering in Jovian atmosphere (with polarization) and in Venus atmosphere (without polarization) were performed. Comparison of synthetic images of Venus with VMC data (Venus Express) allows preliminary studying the geological composition of Venus surface and temperature lapse rate in lower atmosphere. Product Description popup.authors Акімов А. Акімов Л. Бєлкіна І. Бушуєва Т. Великодський Ю. Герасименко С. Дятел Н. Кайдаш В. Корохін В. Марченко Г. Опанасенко М. Шалигін Є. Шалигіна О. Шкуратов Ю. popup.nrat_date 2020-04-02 Close