Snowfall and Temperature on a California Mountain

Abstract

A SNOWFALL and temperature analysis has been completed for six winter seasons (1948–54) on White Mountain, California (elevation 10,600 ft.). Snowfall and the temperature maxima and minima were measured for every 24 hr. at 0800 Pacific Standard Time. Fig. 1a shows the total snowfall as a function of the mean air temperature of the day on which the snow fell. An interesting peak occurs at − 11 ° C., just as Bossolasco reports¹ for the case of snowfall at Weissfluhjoch. Rau's laboratory work² indicates that the majority of atmospheric nuclei induce freezing between − 10° and − 12° C. Silver iodide begins its activity as a freezing nucleus in the laboratory at − 4° C. ³, and at this point Fig.1a shows another peak. Bossolasco has also mentioned that Mason and Ludlam⁴ report this point as a secondary maximum in laboratory frequency of atmospheric freezing nuclei. However, it is believed that the − 4° C. peak may be related to large cloud-seeding experiments utilizing silver iodide smoke carried on in the Sierra Nevada Mountains about thirty miles up wind to the west⁵ during the seasons 1951, 1952 and 1953. Vonnegut⁶ expected that unusual and far-reaching effects must be expected in the case of such seedings, since silver iodide is much more active than any known natural ice nucleus.