A STATISTICAL COMPARISON OF METEOROLOGICAL DATA WITH DATA OF RANDOM OCCURRENCE

Abstract

SYNOPSIS Daily, monthly and annual means of meteorological data show fluctuations of varying orders of magnitude, which may be regarded as either of a fortuitous character or as presenting more or less systematic characteristics. Certain precise relations which are distinctive of purely fortuitous data are derived by both theoretical and empirical methods. These relations constitute criteria for determining the extent to which meteorological data differ from such fortuitous data. Monthly and annual means of temperature are nearly Gaussian in their distribution, their deviations being of the nature of accidental errors. but the order of succession of their occurrence is not fortuitous. Rainfall data are more fortuitous in their characteristics than temperature. In a plot of unrelated numbers the two-interval is predominant, while in the case of most meteorological annual means the three-year interval is the most frequent. The variations of mean annual temperatures show systematic characteristics to a greater extent in the Southern Hemisphere and the low latitudes of the Northern Hemisphere than in the higher latitudes of the Northern Hemisphere. Statistical criteria a plied to the variations of the period of the solar spots disclose markedly systematic characteristics. A period of recurrence of extremes of pressure at Toronto, averaging 32 to 34 days seems to be disclosed by a purely statistical method of treatment of the dates of highest and lowest pressure in each month for a long aeries of years.