Where has all the snow gone? Snowpack sublimation in northern Utah

Climatic data for twenty-one winters was used to construct an index to assess the significance of evapo-sublimation at Flagstaff, Arizona. Large intra- and inter-annual variability was noted in the record using this 'sublimation opportunity index' as well as a similar one based on ('corrected for') the presence of snowcover.An instrument to record evapo-sublimation has been developed and preliminary data is presented which compares values from this 'sublimimeter' to the index values for periods in 1990-91 and 1991-92.While the index is not a predictive model, relatively good (R2 = 0.62, cross-correlation coefficient = 0.89, cross association value = 79%) agreement is found between index values and the observed values.It appears that at least 22% and as much as 70% of the snowpack at this high elevation site may be lost to sublimation and, therefore, that the date of snowpack accumulation is critical to the runoff efficiency of high elevation snowpacks.