Council Snowmelt 2000

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Council Snowmelt 2000
Image Courtesy Bob Huebert / ARSC
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Council Snowmelt 2000
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Council Snowmelt 2000
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Snow Surveys, Council Alaska Julie Knudson Anne
Carr, Water and Environmental Research Center,
University of Alaska   Comprehensive snow surveys
were performed on both the Melsing Creek and Guy
Rowe drainages to establish the pre-melt snow
cover. Daily snow survey sites were also
established at a representative forest, shrub,
and tundra site within the Melsing Creek
watershed, where snow pits were dug, ablation
poles installed, and daily depths and snow water
equivalent were measured.   For every snow water
equivalent measurement, double sampling was used.
Ten snow densities were collected and 50 depths
were measured. At each site ablation stakes were
installed along a transect that trended
east/west. Three stakes were installed at each
site approximately 25 feet apart with the entire
transect 50 feet long. The 50 depths were
measured on a line parallel to the ablation poles
and were taken approximately every 2 feet on both
the north and south side of the line. In
addition, the ablation poles were also read and
these results were plotted for each pole.
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There were two warming trends observed, with a
period of refreezing in between. In response to
the refreezing, the river stage dropped with the
temperature. May 7 represented the start of the
initial melt, with day temperatures above 0oC.
Temperatures remained above 0oC at night for the
first time on May 16. The ablation graphs show
this first melt period occurring between May
11-May 20, with the dates fluctuating dependent
on the site. The temperature began to drop
approximately on May 18 and remained cold until
May 23. The second melt period responded to
warming temperatures by May 27, with nightly
temperatures again above 0oC by May 29. The first
major rain event occurred May 31- June 2, this
corresponds to the peak discharge on Melsing
Creek. Complete melt occurred at the Shrub site
on May 30 and the Forest site on June 3. The last
measurement at the Tundra site occurred on June
9, with an estimated 4 days until complete melt
in the entire basin.
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Shrub Site
Tree Site
Tundra Site
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Snowpack Ablation
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Snowpack ablation during spring, 2000 displays
remarkable variability among the many sites where
snowmelt processes were monitored.
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Anne Carr
Julie Knudson
Funding for this research was provided by the
National Science Foundation Arctic Systems
Science Program (Grant No. OPP-9818066).