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
Albedo One writing of genre author Gene Wolfe. These columns are often noted for their "opinionated" or controversial stance on genre matters, with that in issue 31 of "Albedo One" being described as "a deliberately provocative rant" by one reviewer. In 1996 the editors offered an open invitation, stating that "If you feel strongly about anything and want to let us and the readers know, you too can don the mightly mantle of Severian." Between 1997 and 1999 "Albedo One" was honored three times by the European Science Fiction Society, winning Awards for "Best Magazine" and "Best Publisher". Stories from the magazine