a measure of the additional absorption of solar radiation from light absorbing particles (LAP) such as dust or soot. Units of measure are Watts per square meter (W/m2) and values can range from 0 to 500 W/m2. The maximum value depends on incoming solar radiation (elevation, direct sun vs shaded) and the amount of dust or soot. A value of 0 means no additional radiation is being absorbed. A value of 500 means nearly all of the solar energy is absorbed (depends on latitude, elevation, clouds). Radiative forcing is calculated by the difference between the net (downward minus upward) radiative fluxes (irradiance) with and without LAP.