A CCD camera and a laser measure the properties of these substances in the CLidar (KLYE-dar) technique. A quantity characterizing these substances is denoted by lowercase g and is calculated by an intensity-weighted integral over all azimuthal angles. NASA's MODIS instrument measures the asymmetry parameter and optical depth of these substances, which may be (15[1])classified into an “accumulation mode” or a “coarse mode” based on (15[1])size. In (15[1])aggregate, the anthropogenic (*) “loading” of these substances has produced a net negative radiative (10[1])forcing, in part (10[1])since these substances directly scatter (10[2]-5[2])sunlight and provide (-5[2])nuclei for (-5[1])cloud (-5[1])condensation. (-5[2])Volcanic eruptions produce (10[1])“primary” examples of, for 10 (-5[1])points, what collections of atmospheric particulate matter, a type of colloid in which (10[1])a solid is (10[1])dispersed in a gas? (10[8]0[2])■END■