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Research subject. Based on the two-stage mechanism of the Earth's heterogeneous accumulation, previously proposed by V.N. Anfilogov and Yu.V. Khachay, the thermal evolution of the core during its formation was studied. Account is taken of both the heat release from 26Al, the content of which was established with a fairly reliable accuracy, and that from 60Fe.Materials and methods. The methods of mathematical modelling were used. Calculations were carried out for three estimates of the fractional content of the radioisotope 60Fe to stable 56Fe at the time of CAI formation (Ca-Al-In- clusions, calcium- and aluminium-rich inclusions found in carbonaceous chondrites) based on the results of various authors.Results. As a result of numerical experiments, variants of the temperature and melting temperature distributions at different stages of the core formation for different 60Fe/56Fe ratios were obtained.Conclusions. The results show that the central region of the forming core can remain melted even by the end of its accumulation. As a consequence, in this region for this time, the conditions for free thermal convection and, accordingly, for the implementation of the MHD dynamo mechanism remain.

Research subject. The relationships between heat fluxes and ground surface temperatures in a diurnal cycle.Methods. Experimental studies, including actinometric observations and monitoring of surface temperatures and surface heat fluxes for a soil and an artificial layer, were performed at the Verkhnee Dubrovo meteorological station in 2020.Results. The surface heat flux varies synchronously both with the total solar radiation near the earth’s surface and insolation at the upper boundary of the atmosphere. Maximal values of these heat fluxes are observed at the solar noon. The temperature response lags behind them by the time interval determined by the soil’s thermal heterogeneity. In this study, we extend our model of the ground surface temperature response to external radiative forcing, which was developed earlier, to the case of a thermal inhomogeneous half-space. An analytical expression for the simplest case of inhomogeneity (the presence of an upper layer with thermal properties different from those of the underlying rocks) is given and investigated. If the upper layer demonstrates a reduced thermal conductivity, the phase shift between the heat flux and the temperature response decreases in comparison with the value for a homogeneous half-space (45°).Conclusion. The soil studies conducted at the “Verkhnee Dubrovo” meteorological station allowed us to construct a thermophysical section and to verify the previously developed model using experimental data. The errors of theoretical estimates, in general, do not exceed those of the phase estimate at a 10-minute sampling rate. The obtained results can be applied when conducting climatic (including palaeoclimatic) and environmental studies, as well as when investigating heat exchange processes on artificial urban surfaces and their role in the formation of urban heat islands.

tional field during the growth of the planet and the angular velocity of the Earth's rotation. Further Research: It is proposed to extend the results obtained to the conditions for taking into account the dynamics of the double Earth-Moon system.

In previous studies it was shown that the energy release during the decay of short-living radioactive elements in small bodies is sufficient for the temperature inside such a protoplanetary core to become larger than the melting temperature of iron. This ensures the realization of the process of differentiation of matter and the development of convection in the inner envelopes. At all stages of proto-Earth's formation, convective heat and mass transfer is the most important factor in the dynamics of the planet. However, the release of heat due to friction in the viscous liquid of the outer regions of the core so far has not been taken into account at all or was taken into account only in the formed envelopes of a planet of constant radius. In this chapter, we present the results of a numerical simulation of the thermal evolution of a 3D spherical segment of a protoplanet of an increasing radius, taking into account the accidental falling of bodies and particles. An algorithm for the numerical solution of the problem is given, taking into account the dissipation of tidal energy in the Earth-Moon system at the stage of planetary accumulation.