Persistence and Recurrence Probabilities of Cloud-Free and Cloudy Lines-of-Sight Through the Atmosphere

Abstract

A total of 13,215 high-contrast, whole-sky photographs were studied to derive estimates of cloud-free and cloudy line-of-sight persistence and recurrence probabilities. There were 585 hr when photographs were taken every 5 min, without interruption, and 885 days when photographs were taken every hour from 0900 through 1500 LST. Data taken from these photographs were processed to obtain relative frequencies of cloud-free or cloudy lines-of-sight given the initial condition. The conditional relative frequencies were used in deriving conditional probability estimates. The resulting probability estimates are judged to be realistic and applicable to many locations.