okta

1. (meteorology) One eighth of the total area of the celestial dome; used as a measure of cloudiness (one okta means that one eighth of the sky is obscured, two oktas that one quarter is obscured, and so on).Examples: "...64% of the low- and 50% of the high-cloud amount differences were within ± 1 okta, although many of these successes (71% in the low-cloud amount) were for cases of totally clear or totally cloudy skies."; "‘Fog is traditional for the season and cloud is anticipated at six to seven oktas, sir.’"; "Mean cloud amount distributions are transformed to normal distributions. The accuracy of the method is indicated by the retrieval of the original distribution with a typical error of 14% in the frequency of each okta of cloud amount."