Evaluation of several degree-day estimation methods in California climates

摘要: Procedures for estimating degree-day accumulations are frequently employed instead of the more accurate method calculating degree-days from hourly temperature data because on-site commonly restricted to daily minimum and maximum records. Data seven methods at each nine locations during 2 years in California were compared by month values calculated summation. Methods included three sine-wave approaches, triangulation approaches averaging (i.e., rectangle) method. Results double-sine corrected-sine corrected day length) nearly identical those single-sine The double produced very similar results single deviated a greater extent temperatures November through February than did methods. Degree-day estimations late spring summer months one another all estimation cooler year. Since no advantages noted complicated methods, or is preferred as they less procedures. Of various threshold cut-off evaluated, error levels unaffected when using employment horizontal with not significantly increase amount degree-days. However, an was observed employing intermediate vertical techniques computing