On the Linear Relationhip Between Daily Relative Sunshine Duration and Daily Mean Cloud Cover
Abstract
This paper explores the relationship between daily relative sunshine duration – S and daily mean cloud cover – C. A theoretical model that leads to the idealized linear relationship S=1-C often encountered in literature is derived, based on well-defined simplifying assumptions. We demonstrate the application of the theoretical model to vertical visibility and cloud cover readings by ceilometer. We explore the deviations from linearity in the real world in the context of the theoretical model. An estimate of the relationship between measurements of S and C based on sunshine recorders, ground based human observers, and ceilometers is given.
Keywords
Ceilometer, Climatology, Cloud cover, Sunshine, Stochastic modeling