Abstract
The mass release of intercepted snow on the lower part of the canopy of an Abies mariesii forest in a mountainous area of Fukushima Prefecture, Japan, was measured using time-lapse cameras to clarify the relationships between the occurrence of snow mass release and meteorological conditions. Based on the number of occurrences in a 1-h shooting interval, mass release events can be classified into the following two types: Type I events, in which a limited number of mass releases are recognized, and Type II events, in which mass releases are recognized at many branches during a shooting interval. Moreover, Type II events can be classified into two types: Type II-A, in which most of the intercepted
snow masses on many branches are released rapidly and disappear in several hours, and Type II-B, in which snow masses on many branches continue to be released gradually for several days. A comparison with the meteorological conditions at a weather station near the observation site during each type of mass release event revealed that Types I, II-B, and II-A occur mostly when air temperature is lower than 0℃, between 0 and 2℃, and higher than 2℃, respectively. In contrast, no significant differences of mass release event type were associated with differences in wind speed or global radiation. These results indicate that mass release of intercepted snow on the lower part of the canopy is controlled mainly by air temperature.
