Accumulation distribution in terre adélie, antarctica: effect of meteorological parameters

Abstract

ABSTRACT. Along the 1040 km extending from Cape Prud'homme (lat.66°4I'S., long.139°55'E.), near Dumont d'Urville station, to Dome C (lat. 74 °39 , S., long. 124 ° 10' E.), the variations in annual accumulation can be analysed by a division of the entire data set into three sub-sets depending on the types of measurements and the character of the spatial distribution. Along the first 33 km, from the coast to stake E40, annual measurements show considerable inter-annual variability, 52% of which can be explained by the spatio-temporal homogeneity of the balance distribution. However, we obtain a better result (64%) for the fluctuation homogeneity standardized using the standard deviation. This means that there is a strong space-time distribution structure, characterized by an equal variation of the balance around the mean value specific to each location. This is so in spite of the existence of considerable surface roughness (sastrugi), the influence of which should be reduced by averaging values around each stake. From stake E40 to stake R60, a distance of 170 km, the almost periodic oscillations in the accumulation with a wavelength close to 40 km can be explained by the formation of a gravityinertia wave, disturbing the geostrophic equilibrium, occurring at the break in slope 200 km from the coast. The very low values of accumulation for stakes D55 and D58S show that the oscillations were almost stationary during the study period (about 25 years). Finally, along the 840 km from stake R60 to Dome C we can observe a decrease in accumulation resulting from the decrease in mean temperature.

Ground‐based measurements of spatial and temporal variability of snow accumulation in East Antarctica

“…Wind erosion, wind redistribution, sublimation, and other processes during or after the precipitation event lead to a deposition at the surface which is spatially less homogeneous than the original precipitation. Variations in accumulation over tens of kilometers have been observed since the 1960s [Black and Budd, 1964;Pettré et al, 1986]. These accumulation variations and surface processes result in surface features including sastrugi, longitudinal dunes [Goodwin, 1990], dunes on the 100-m scale Karlöf et al, 2005b], and, most impressively, megadunes on a kilometer scale [Fahnestock et al, 2000;Frezzotti et al, 2002a].…”

An up‐to‐date quality‐controlled surface mass balance data set for the 90°–180°E Antarctica sector and 1950–2005 period

“…This difficulty does not prevent from obtaining reliable observed SMB data in studied areas, as attested by other reliable SMB measurement methods in most of the previous cited works. However, several authors showed very large standard deviations (up to 150%) in the accumulation pattern derived from annual SMB stake farms (or single stake) measurements [Petit et al, 1982;Pettre et al, 1986;Mosley-Thompson et al, 1999;Goodwin et al, 2003;Frezzotti et al, 2005]. As pointed out by Fisher et al [1985], the observed variability limits the degree to which a single annual snow accumulation value may be temporally representative of the local SMB on longer period.…”

Recent intra‐annual snow accumulation at South Pole: Implications for ice core interpretation

“…Wind velocities at South Pole are quite high, particularly during winter months, and we hypothesize that the very large stake-to-stake variability in monthly accumulation is primarily caused by these high winds since snow transport is highly dependent on wind speed [Pomeroy and Jones, 1996;Pettre et al, 1986]. The standard deviation in gross monthly accumulation is plotted in Figure 7, along with two indicators of windiness during each accumulation month.…”