Accepted for publication in Hydrological Processes
Robert F. Harrington and Roger C. Bales
Patrick Wagnon
Hydrology and Water Resources Department,
University of Arizona,
Tucson, Arizona 85721
Laboratoire de Glaciologie et de Geophysique,
Grenoble, France
volume of snow was placed in
a plexiglass box, and melted from above using
a heating plate.
The meltwater and solute
fluxes issuing from the bottom of the snow
were monitored.
In experiments with NaCl tracer added to
the snow,
solute concentrations
were generally lower in the flow fingers than in the
background wetting front.
Dye tracer experiments revealed contemporaneous
areas of concentrated dye and dilute meltwater
in flow fingers.
This suggests that the meltwater in
flow fingers is diluted by low concentration water
from the top of the snowpack. Flow fingers contribute more
meltwater flux primarily because flow is maintained for a
longer period of time than in the non-finger areas;
however, the relative contribution of flow fingers to solute flux
apparently was not as great as that of the background wetting front
because of dilution of solute in the flow finger areas.
Figure 1: Plan view of snow box. Data from the
sixteen central compartments are
used for analysis.
Figure 2: Mean flow rate and
concentration factor for each
ionic tracer experiment.
Figure 3: Histogram of arrival times of meltwater at the
base of the snowpack
for the sixteen flow channels for the ionic
tracer experiments. Black indicates
finger flow areas; white indicates background wetting front.
Figure 4: Flow
rates and concentration factors for ionic tracer
experiments. Solid lines are flow finger
affected areas; dashed are background wetting
front areas.
Figure 5: Cross section of dyed flow finger twenty h into
experiment C. The image is classified into three
zones: white areas
are dry snow; black areas are areas of wet snow
with concentrated dye; and
gray areas are wet snow where the dye is relatively dilute.
