Cloud transient characterization in different time steps

Abstract

In this paper we evaluate the cloud transients by analyzing the dynamics of the direct fraction index kb for one year of solar radiation data in different time steps. We use instant 5-sec data integrated data and compare the number and percentage of occurrences of the different defined sky conditions. We find that the most common situation is a progressive transient and that the average transient lasts between one and 5 minutes. We also perform a cloud transient duration analysis observing that the denser clouds have greater persistence.