AN ELEVATIONAL CONTROL OF PEAK SNOWPACK VARIABILITY¹

Abstract

The records of the seasonal peaks in snow accumulation on 24 snow courses show that the relative variability (measured by the coefficient of variation) is inversely related to elevation in the San Juan Mountains, southwestern Colorado. Analysis on an annual basis shows that this is due to a tendency for the peak snowpack at high elevations to be closer to the long‐term mean while that at low levels is further from the normal. This is true in both above‐normal and below‐normal accumulation seasons. Extrapolation of 20 annual elevation‐accumulation trends suggests that mean accumulation is reached at 4107 ± 186 m elevation. This is approximately the height of the topographic harrier of the San Juan Mountains suggesting that the pattern of variability is a partial function of an atmospheric‐topographic interaction.

Climatic Change in the Colorado Rocky Mountains: Estimates Based on Modern Climate at Late Pleistocene Equilibrium Lines

“…Along a particular side of a single range, however, there is generally a fairly strong relationship between altitude and snow accumulation, as has been noted by other workers (Caine, 1975;Barry, 1981;Porter et al, 1983;Zielinski and McCoy, 1987). Along a particular side of a single range, however, there is generally a fairly strong relationship between altitude and snow accumulation, as has been noted by other workers (Caine, 1975;Barry, 1981;Porter et al, 1983;Zielinski and McCoy, 1987).…”

Use of April 1 SWE measurements as estimates of peak seasonal snowpack and total cold‐season precipitation

“…The amount of runoff available in any given year is largely determined by the amount of precipitation received in the previous winter, so an understanding of precipitation patterns is important in gauging future water supplies. Much research has been performed in this region over the past several decades relating winter precipitation to elevation, aspect, global atmospheric circulation, and a variety of other factors [e.g., Spreen, 1947;Caine, 1975 with an antifreeze solution. As snow accumulates on top of the pillow, the pressure on the solution increases owing to the increased overlying mass.…”

“…The amount of runoff available in any given year is largely determined by the amount of precipitation received in the previous winter, so an understanding of precipitation patterns is important in gauging future water supplies. Much research has been performed in this region over the past several decades relating winter precipitation to elevation, aspect, global atmospheric circulation, and a variety of other factors [e.g., Spreen, 1947;Caine, 1975;Changnon et al, 1991Changnon et al, , 1993McCabe, 1994;Johnson and Hanson, 1995]. Much of this research has been based on measurements from highelevation snow courses, where the snow-water equivalent ( Figure 1) has allowed the measurement of SWE at any time interval.…”

Effects of sample and grid size on the accuracy and stability of regression‐based snow interpolation methods

“…Altitude determines the type of precipitation (solid or liquid) and the evolution of melting in a given area (Caine, 1975;Balk and Elder, 2000). Slope of the cell is recognized to affect snow redistribution processes (Mittaz et al, 2002).…”