The paper presents results of theoretical analysis of microphysical optical characteristics of atmospheric aerosol such as source function of electromagnetic energy absorbed in the particle volume, as well as absorption efficiency, absorption asymmetry, and radiation pressure factors. We present calculated results on these characteristics, obtained on the basis of Lorentz-Mie theory for different types of atmospheric aerosol, and discuss their dependence on the parameters influencing them. We intend to use these results for experimental study of dynamics of microparticles in the field of directed low-intensity radiation, mimicking the behavior of tropospheric and stratospheric aerosols.