TY - JOUR AU - Frezzotti, M. AU - Gandolfi, S. AU - Urbini, S. PY - 2002// TI - Snow megadunes in Antarctica: Sedimentary structure and genesis T2 - J. Geophys. Res. JO - Journal of geophysical research-atmospheres VL - 107 PB - American Geophysical Union KW - 1827 Hydrology: Glaciology KW - 1863 Hydrology: Snow and ice KW - 1894 Hydrology: Instruments and techniques KW - 3322 Meteorology and Atmospheric Dynamics: Land/atmosphere interactions KW - 5470 Planetology: Solid Surface Planets: Surface materials and properties N2 - Megadune fields occupy large areas in the interior of the East Antarctic ice sheet and are the result of unusual snow accumulation and redistribution processes. They therefore are important to surface mass balance and ice core interpretation. Field observations (GPS, GPR, and surface measurements) have provided a detailed description of megadune sedimentation and morphology over a 70 km2 area, located 200 km east of Dome C. A combination of remote sensing analysis (using Landsat and satellite radar altimetry) and field measurements indicate that slope in the prevailing wind direction (SPWD) and climatic conditions play a crucial role in megadune genesis. The megadune areas tend to be characterized by slightly steeper regional slope and the presence of highly persistent katabatic winds. The megadunes represent 2 to 4 m amplitude waves of 2 to 5 km wavelength formed by variable net accumulation, ranging between 25% (leeward faces) to 120% (windward faces) of the accumulation in adjacent nonmegadune areas. Leeward faces are characterized by glazed, sastrugi-free surfaces and extensive depth hoar formation. Windward faces are covered by large rough sastrugi up to 1.5 m in height. SN - 0148-0227 UR - http://dx.doi.org/10.1029/2001JD000673 N1 - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=5631), last updated on Thu, 15 Jul 2010 15:02:27 +0200 ID - Frezzotti_etal2002 ER -