THE DISTRIBUTIONS OF FREEZE-DATE AND FREEZE-FREE PERIOD FOR CLIMATOLOGICAL SERIES WITH FREEZELESS YEARS

H. C. S. THOM Office of Climatology, U.S. Weather Bureau, Washington, D.C.

Search for other papers by H. C. S. THOM in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

It is shown that the freeze distribution is a mixture of the distribution of freeze-date and the simple dichotomous distribution of freeze and freezeless years. This is applied both nonparametrically and assuming a normal distribution of freeze date to three stations at three different thresholds to obtain the probabilities of freeze before or after any date. The distribution of the freeze-free period is developed and application made to one of the stations to obtain probabilities of the freeze-free period being less than a given time interval. The expressions for the mean freeze-date and freeze-free period are also developed and estimates made for the stations treated.

Abstract

It is shown that the freeze distribution is a mixture of the distribution of freeze-date and the simple dichotomous distribution of freeze and freezeless years. This is applied both nonparametrically and assuming a normal distribution of freeze date to three stations at three different thresholds to obtain the probabilities of freeze before or after any date. The distribution of the freeze-free period is developed and application made to one of the stations to obtain probabilities of the freeze-free period being less than a given time interval. The expressions for the mean freeze-date and freeze-free period are also developed and estimates made for the stations treated.

Save