Cloud cover Cloud cover Cloud cover (also known as cloudiness, cloudage, or cloud amount) refers to the fraction of the sky obscured by clouds when observed from a particular location. Okta is the usual unit of measurement of the cloud cover. The cloud cover is correlated to the sunshine duration as the least cloudy locales are the sunniest ones while the cloudiest areas are the least sunny places. The global cloud cover averages around 0.68 when analyzing clouds with optical depth larger than 0.1. This value is lower (0.56) when considering clouds with an optical depth larger than 2, and higher when
Digit (unit) Digit (unit) The digit or finger is an ancient and obsolete non-SI unit of measurement of length. It was originally based on the breadth of a human finger. It was a fundamental unit of length in the Ancient Egyptian, Mesopotamian, Hebrew, Ancient Greek and Roman systems of measurement. In astronomy a digit is one twelfth of the diameter of the sun or the moon. The digit, also called a finger or fingerbreadth, is a unit of measurement originally based on the breadth of a human finger. In Ancient Egypt it was the basic unit of subdivision of the cubit. On