The Freeze Risk to Florida Citrus. Part II: Temperature Variability and Circulation Patterns

Abstract

Severe freezes are a serious problem for the citrus growers of central Florida. To investigate possible climatic causes of intermittent freezes, this paper examines the influence of several atmospheric circulation patterns on winter temperatures in Florida. The Pacific/North American pattern is shown to be particularly influential and the North Atlantic Oscillation also to be significant, while the Southern Oscillation does not show a direct effect. A decreasing trend in Florida winter temperatures since 1947 can be explained by fluctuations in the former two circulation patterns. Climate model studies to investigate possible changes in the frequency or location of these circulation patterns could suggest potential changes in the freeze risk associated with climatic change.