Seventh Annual AMS Student Conference


Changes in Arctic Snowfall/Total Precipitation Ratios

Ryan L. Ruhge, University of Nebraska, Lincoln, NE; and S. Feng and M. P. Lawson

One consequence of a changing climate in high latitudes is the probable change in snowfall to total precipitation (S/P) ratios. Increasing temperatures in polar regions should result in a smaller amount of accompanying precipitation being frozen. A major impact of this precipitation change is less resulting snowpack. Snowpack, and the resulting spring runoff, are crucial to the maintenance of regional water supplies throughout the world. Also, a reduction in snowpack and the resulting decrease in albedo and higher surface temperatures will cause changes in the energy budget and the regional climate. This study analyses sub-regional temperature change over the recent 50 years and the resulting impact (decrease/increase) in snowfall with respect to total precipitation poleward of 60 degrees N. Latitude, based on global WMO data available for the circumpolar region. The method employs the current and previous weather conditions from the data to determine the daily, monthly, and annual precipitation type and amount, and an S/P ratio is determined for these data for each station.

Results also are analyzed using a multivariate statistical approach as well as time-series characteristics (5- and 11-year weighted moving means) to attempt to spatially and temporally correlate these results with atmospheric circulation teleconnections. We seek to discover possible stronger associations with these teleconnections, rather than forcing strictly related to global warming, specifically the NAM/NAO index.

Finding the rate at which these ratios are decreasing with respect to the rate of increasing temperatures is the most important conclusion to come from this study. Also, changes in overall precipitation amounts with varying temperatures, and changes in how far north the extent of significant precipitation may be occurring are other expected conclusions to come from this study. The research methodology employed for this study could serve to analyze the S/P ratios of stations at high elevations to document potential similarities/differences with high latitude locations.

Poster Session 1, Student Conference General Poster Session
Sunday, 20 January 2008, 5:30 PM-7:00 PM, Exhibit Hall B

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