Numbers and lengths of snow patches above 600 m altitude in northeast
Scotland were recorded in summer and autumn during the period 1974-198
9, and were compared with regional climate in those years. The number
of patches and their total length declined from July to October and va
ried between years. Only two patches survived through the study. Both
number and total length were strongly related to winter and spring tem
perature and to amounts of snow-drift. Areal density of patches increa
sed with altitude up to 1200 m but decreased sharply on the exposed hi
ll tops above this altitude. The direction of snow-drift affected the
distribution of patches among slopes of different aspect. Most patches
faced northeast or southeast, the same aspect as most corries. In sum
mer, the previous months' climate had little effect on the number or t
otal length of patches in the following month, or on the rate of loss
between months. Patch losses in most summers followed a negative expon
ential decay curve. Our results indicate that summer snow patches are
a useful short-term integrative index of climate change.