Albedo their reflectivities. Fresh 'black' ice exhibits Fresnel reflection. Snow on top of this sea ice increases the albedo to 0.9. Cloud albedo has substantial influence over atmospheric temperatures. Different types of clouds exhibit different reflectivity, theoretically ranging in albedo from a minimum of near 0 to a maximum approaching 0.8. "On any given day, about half of Earth is covered by clouds, which reflect more sunlight than land and water. Clouds keep Earth cool by reflecting sunlight, but they can also serve as blankets to trap warmth." Albedo and climate in some areas are affected by artificial clouds, such as
Surface-to-surface missile bomb was the first operational surface-to-surface missile. Contemporary surface-to-surface missiles are usually guided. An unguided surface-to-surface missile is usually referred to as a rocket (for example, an RPG-7 or M72 LAW is an anti-tank rocket whereas a BGM-71 TOW or AT-2 Swatter is an anti-tank guided missile). Examples of surface-to-surface missile include the MGM-140 ATACMS, the Ground-Launched Small Diameter Bomb (GLSDB) and the Long Range Precision Fires (LRPF). Surface-to-surface missiles are usually broken down into a number of categories: Different parties break down missile type by the range differently. For example, the United States Department of Defense has no definition