Search academic texts

Information × Registration Number 0207U000285, 0102U003757 , R & D reports Title Nonstationary processes on the Sun, in the Solar System and cosmic plasmas popup.stage_title Head Kostik R.I., д.ф.-м.н. Registration Date 19-01-2007 Organization Main Astronomical Observatory popup.description2 Aims: To obtain physical parameters of the dynamical phenomena which define the main properties of the solar photosphere and control the non-radiative energy transfer to the outer layers (chromosphere and corona). The study is based on the observations and theoretical modeling of the optical solar spectra. Methods: Analysis of own and published earth-based and space observations; mathematical modeling. Results: Observations of the Sun and comets were performed. Models of the solar flares at different stages of their evolution were created. It was shown that power of the 5-min oscillations in the solar atmosphere is higher in the regions with enhanced convective motions. This observational fact proves that turbulent convection is indeed an origin of excitation of local solar oscillations. Modeling of acoustic wave propagation in a sunspot has shown that in general there appear two magnetoacoustic modes: fast and slow. An assumption was made that 3-min oscillations which were observed in the sunspot photosphere and chromosphere simultaneously, were caused by the slow magnetoacoustic wave. Coherent non-linear theory of the three-wave interaction which includes Langmuir wave, kinetic Alfven wave and whistler was investigated. Initial stage of the energy exchange between these waves and its following time dynamics were studied. A model of an active region on the comet nuclei was created. It consists of a cavity in the protective dust layer on the bottom of which ice is exposed by the solar radiation. Such crater-like structure increases sublimation flow in 1.5-2.5 times. Results of photometrical observations of Uranus, Titan, Neptune and Triton were gathered and systematized in order to find long-period and short-period oscillations of these objects.5635 Product Description popup.authors popup.nrat_date 2020-04-02 Close