McIntyre (1950) has indicated that the shape of seasonal frequency polygons of temperature at a particular level and station depends on the relative frequency of different air masses at the level. For a summer and a winter month the temperature distribution in various air masses at four levels in the troposphere at Macquarie Island were examined, the stable layers being regarded as air mass boundaries. The histograms show, as expected, that the frequency of occasions of cold air decreases and of warm air increases with height. Given large enough samples, the temperature distribution within air masses at Macquarie Island appears to be normal. This is supported by significance tests. However most of the total distributions below 300 mb, particularly in winter, probably are not normal. As this probably applies at most stations outside equatorial areas, total distributions of temperature will not be adequately defined by their means and standard deviations but could be represented by the means, standard deviations and total frequency of each air mass class contained in the total distribution. This information would be valuable for general studies of the frontal and air mass structure of the atmosphere.
J.N. McRae (Tue,) studied this question.