Da. Braaten, A DETAILED ASSESSMENT OF SNOW ACCUMULATION IN KATABATIC WIND AREAS ONTHE ROSS ICE SHELF, ANTARCTICA, J GEO RES-A, 102(D25), 1997, pp. 30047-30058
An investigation of time dependent snow accumulation and erosion dynam
ics in a wind-swept environment was undertaken at two automatic weathe
r stations sites on the Ross Ice Shelf between January 1994 and Novemb
er 1995 using newly developed instrumentation employing a technique wh
ich automatically disperses inert, colored (high albedo) glass microsp
heres onto the snow surface at fixed intervals throughout the year. Th
e microspheres act as a time marker and tracer to allow the accumulati
on rate and wind erosion processes to be quantified with a high tempor
al resolution. Snow core and snow pit sampling was conducted twice dur
ing the study period to identify microsphere horizons in the annual sn
ow accumulation profile, allowing the snow accumulation/erosion events
to be reconstructed. The two sites chosen for this investigation have
characteristically different mean wind speeds and therefore allow a c
omparative examination on the role of wind on ice sheet growth. Mass a
ccumulation rate at the two sites for the 14-day integration periods a
vailable ranged from 0.0 to >2.0 kg m(-2) d(-1) The mean mass accumula
tion rate during the study period was greater at the site with stronge
r winds (0.69 kg m(-2) d(-1)) than the site with lower mean wind speed
s (0.61 kg m(-2) d(-1)); however, the difference between the two means
is not statistically significant. Accumulation rates derived from an
ultrasonic snow depth gauge operated at one of the sites are compared
to the actual tracer-derived accumulation rates and show the limitatio
ns of only having a measure of snow surface height with no instantaneo
us measurements of the snow density profile. Snow depth gauge derived
accumulation rates were found to be greatly overestimated during high-
accumulation periods and were greatly underestimated during low-accumu
lation periods.