The Asymmetry of Global Solar Radiation Around Solar Noon

Abstract

Using approximately 25 years of rehabilitated global solar radiation measurements, an analysis of the asymmetry of global solar radiation around solar noon was performed for three climatic regions of the United states represented by Miami, Florida; Fort Worth, Texas; and Washington, DC. An asymmetric distribution of the global solar radiation during the summer months was found at all three regions. The most pronounced asymmetry occurred at Miami during July and August: radiation in excess of 12% was received in the morning as compared to the afternoon. At the other station the morning totals exceed the afternoon totals by 3%?4%. At Fort Worth. a reversal in the asymmetry was observed during the spring: the afternoon hours received 3% more radiation than the morning hours. Similar analyses were performed using hourly observations of clouds and resulted in consistent findings.