This suggests that phase D could be the primary carrier of water in thick, cold slabs sinking through the upper mantle. If such cold slabs penetrate the 660-km discontinuity, then water from the sea floor could end up at the bottom of the lower mantle. Most current methods of modeling or measuring sunlight in the Earth's atmosphere treat the intensity of scattered light as a scalar quantity. In truth, the light is described by four Stokes' parameters, a vector that defines its polarization and phase. Lacis et al. return to the fundamentals of radiative transfer and solve for the intensity of scattered sunlight using an exact vector formulation.
Sky brightness is in percent relative to a perfect Lambertian surface.
Upper right, corresponding polar-plot maps show percent of linear polarization for respective intensities.