Statistical analysis of freezing temperatures in Central and Southern Florida

Abstract

The probability distributions of the number of freezing periods per year, their timing and severity are examined at 25 stations in southern and central Florida. The proposed distributions, derived from stochastic crossing theory, provide adequate fits with the exception of three variables at different stations. The estimated parameter values reflect the changing geography of the freeze hazard. The freeze variable that exhibits the greatest variability over the area appears to be the number of periods, while the average severity of freezes and their timings are fairly homogeneous. The theoretical basis of the method permits estimation of the distribution of the dates of first and last freezes and the distribution of the coldest temperature likely to be encountered during any period of interest. The risks of periods of extremely cold temperatures, rarely observed in the historic records, may also be obtained from those at the more commonly encountered level. The technique provides a thorough yet easily interpreted summary of cold-spell risks at any location.

Patterns of habitat use by the Asian citrus psyllid,Diaphorina citri, as influenced by abiotic and biotic growing conditions

“…To determine how biotic and abiotic factors may influence D. citri abundance of particular groves during winter, we examined a number of landscape characteristics potentially associated with D. citri abundance. Winter in Florida is a variable season with periods at around 23 °C to brief overnight frosts as low as −10 °C, which are damaging to citrus trees (Waylen, ). During cold nights, the coolest layer of air is between the ground and 1.5 m above, which can be 2–6 °C cooler than ambient temperature (Bill et al , ).…”

“…Florida has a subtropical climate dominated by hot and wet summers with warm and dry winters. There is also a risk of sustained temperatures below 0 °C (Waylen, ) that may lead to citrus tree loss and D. citri population reduction.…”

Investigating teleconnection drivers of bivariate heat waves in Florida using extreme value analysis

“…This approach unifies existing approaches to the modeling of extremes, namely the peak over threshold (POT) and block maxima approaches which have been applied extensively in hydrological and climatological studies of events above high or low thresholds (Rice 1945;Leadbetter et al 1983;Rodriguez-Iturbe and Bras 1985;Waylen 1988;Waylen and LeBoutillier 1989;Goto-Maeda et al 2008;Waylen et al 2012). The point process is formulated in terms of the limiting Generalized Extreme Value (GEV) distribution parameters (µ, σ, ξ) and as a result, extremal properties are characterized by only these three parameters (Coles 2001).…”

The stochastic properties of high daily maximum temperatures applying crossing theory to modeling high-temperature event variables

“…The probability distributions of the dates of first, F(x≤t), and last, L(x≤t), events can be calculated from the timedependent function shown above as demonstrated by Waylen (1988):…”

“…When a variable, such as daily maximum temperatures, exhibits a distribution that is approximately Gaussian, many of its properties can be predicted using the simple statistical framework outlined in Crossing Theory (Rice 1954;Leadbetter et al 1983;Rodriguez-Iturbe and Bras 1985). In particular, the theory is applicable to the estimation of stochastic properties of the variable beyond a given level, and has been used extensively in studies of flood event, as well as in the analysis of freeze probabilities (below threshold) (Waylen 1988;Waylen and LeBoutillier 1989;Goto-Maede et al 2008).…”