The sunshine state: investigating external drivers of sky conditions

Abstract

Following rapid population growth and urbanization in Florida, there is an increased demand for energy. The state currently gets more than 50% of its electricity from burning imported natural gas. As the future of fossil fuels is uncertain and their impact on climate has proven negative, one could expect great potential and interest in further developing the solar industry, which utilizes the most prominent of renewable energy sources in Florida. Solar energy production is dependent on the supply of clear skies and plentiful insolation. This paper seeks to explain variations in the number of clear sunny days by identifying the months with clearest (cloudiest) sky conditions during the years 1950–2009 in relation to some of the most dominant low frequency climate patterns of variability in the Northern Hemisphere. The hypergeometric distribution is used to test for significant association between the phases of El Niño Southern Oscillation (ENSO), North Atlantic Oscillation, Pacific-North American, and Atlantic Multi-decadal Oscillation (AMO) and cloud cover in Florida. We find that ENSO and AMO significantly impact the occurrence of clear/cloudy skies with the warm phase of ENSO associated with cloudier conditions across much of the state and the warm phase of AMO bringing clearer conditions to northern stations.