Thermal emission spectra of the zodiacal cloud predicted by IMEM for the apex of Earth’s motion around the Sun and the ecliptic pole, assuming that the dust particles are composed of amorphous carbon (top), silicate (middle), and iron (bottom) material. Thick curves are the excess temperatures with respect to the blackbody emission of the CMB (right scale), thin curves are the absolute intensities of emission (left scale). Also plotted are the absolute intensities of the Kelsall model for the wavelengths at which it was normalized to the observations (squares, see Fig. 15 for description).