Albedo distribution of solar radiation reaching the Earth's surface. These factors vary with atmospheric composition, geographic location and time (see position of the Sun). While bi-hemispherical reflectance is calculated for a single angle of incidence (i.e., for a given position of the Sun), albedo is the directional integration of reflectance over all solar angles in a given period. The temporal resolution may range from seconds (as obtained from flux measurements) to daily, monthly, or annual averages. Unless given for a specific wavelength (spectral albedo), albedo refers to the entire spectrum of solar radiation. Due to measurement constraints, it is often given
Albedo 0.39 light it receives that is reflected back into space. The album title refers to the average albedo value of the planet Earth as it was in 1976. From the explanation on the back of the LP cover : ""The reflecting power of a planet or other non-luminous body. A perfect reflector would have an Albedo of 100%. The Earth's Albedo is 39%, or 0.39"". As with "Heaven and Hell", it was performed at the Royal Albert Hall in 1977. The album reached #18 on the UK Album Charts. In 2011 the album was included along with "Heaven and Hell" and