Many parts of the world are presently experiencing a decrease in the daily temperature range, and a number of investigators in the past have suggested that this change in climate may be related to the observed buildup of greenhouse gases. However, other geophysical variables, themselves related to increases in greenhouse gases, may be influencing the daily temperature range. In this investigation, we demonstrate a statistically significant, inverse correlation between the area of North American snow cover and the United States diurnal temperature range. Because global warming is expected to reduce the areal extent of snow cover, the results of this study reveal snow cover should act to increase the diurnal temperature range in the years to come. This climate variable appears therefore to be influencing the daily temperature range counter to other feedbacks discussed in previous studies. Ultimately, our work demonstrates tht the direct linkage between the diurnal temperature range and greenhouse gases may be complicated by feedbacks associated with other geophysical variables. ¿ American Geophysical Union 1992 |