Determination of the coefficient of effective thermal diffusivity of soil under natural changes in environmental conditions

An experimental setup and a data processing technique have been developed to obtain the soil temperature distribution in depth and in time. The results of measuring the soil temperature during 2021 in the city of Ramenskoye, Moscow Region at depths from 0 to 1.475 m are obtained and presented. An analytical solution of the problem of heat transfer in the soil based on the superposition principle is shown and verified. The coefficient of effective thermal diffusivity of soil a = 0.99 · 10−6 m2/s was determined indirectly in a passive experiment. Conclusions are drawn about the coincidence with the results of the experiment of the asymptotic nature of the dependence of the analytical solution for determining the amplitude of soil temperature fluctuations on depth and linear for the phase. An analytical solution is presented to obtain the temperature distribution in the soil with the known law of temperature fluctuations on the surface and the coefficient of effective thermal diffusivity.