Thermal field of a multilayered sphere

The thermal field of a multilayered isothermal sphere placed in a transparent medium is calculated. Second moments of the fluctuating thermal field components including spectral electric and magnetic energy density are determined both in quasistatic and in the far-field regions. The radiant flux flowing out of sphere is also calculated. The formulas obtained are the generalization of the Levin-Rytov´s result for the thermal field of a homogeneous sphere. The result is valid for all radii, frequencies and complex dielectric constants of the sphere layers. It is illustrated by the example of the thermal emission of a wet snow flake