Development of a Global Cloud Model for Simulating Earth-Viewing Space Missions

The beta distribution: A statistical model for world cloud cover

“…Greaves, Spiegler, and Willand [2] suggest a method for doing this using the normal probability distribution. They state two reasons why this distribution was chosen.…”

“…Inspection of the empirical cloud cover frequency curves [Sherr et al, 1968;Greaves et al, 1971] shows distributions Copyright ¸ 1974 by the American Geophysical Union. whose shapes vary from U shaped through transitional J shapes to bell-shaped distributions.…”

“…It is frequently desired to predict cloud cover within much larger areas. Greaves et al [1971] suggest a method to do this using the normal probability distribution. They give two reasons why this distribution was chosen: first, 'It gives acceptable results,' and second, 'it is well known and widely tabulated.'…”

“…The purpose of this report is to present an adequate underlying theoretical statistical distribution to represent worldwide cloud cover. Cloud cover is obviously very important in all earth-space experiments, and considerable work has been performed in developing empirical global cloud cover models [Sherr et al, 1968;Brown, 1970;Greaves et al, 1971;Chang et al, 1972]. These studies have divided the earth's surface into 29 regions as shown by Figure 1.…”

Meteorological satellite accomplishments

“…Park, et al (1974) have demonstrated that brightness measurements can be used to estimate cloud type heights, especially for well developed cumulonimbus. Greaves (1973) developed a relationship between ground and satellite derived cloud amount frequency distributions. This relationship was used in a .statistical modelling technique to describe global cloudiness.…”