Snow accumulation and compaction derived from GPR data near

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TitleSnow accumulation and compaction derived from GPR data near Ross Island, AntarcticaAbstractWe present an improved method for estimating accumulation and compaction rates of dry snow in Antarctica with ground penetrating radar (GPR). Using an estimate of the emitted waveform from direct measurements, we apply deterministic deconvolution via the Fourier domain to GPR data with a nominal frequency of 500 MHz. This reveals unambiguous reflection horizons which can be observed in repeat measurements made one year apart. At two measurement sites near Scott Base, Antarctica, we extrapolate point measurements of average accumulation from snow pits and firn cores to a larger area by identifying a dateable dust layer horizon in the radargrams. Over an 800 m x 800 m area on the McMurdo Ice Shelf (77◦450S, 167◦170E) the average accumulation is found to be 269 ± 9kgm−2 a−1. The accumulation over an area of 400 m x 400 m on Ross Island (77◦400S, 167◦110E, 350 m a.s.l.) is found to be higher (404 ± 22 kg m-2 a -1) and shows increased variability related to undulating terrain. Compaction of snow between 2 m and 13 m depth is estimated at both sites by tracking several internal reflection horizons along the radar profiles and calculating the average change in separation of horizon pairs from one year to the next. The derived compaction rates range from 7 cm m-1 at a depth of 2 m, down to no measurable compaction at 13 m depth, and are similar to published values from point measurements. Copyright 2011 Author(s).AcknowledgementsThe authors would like to thank Steven Arcone and Olaf Eisen for their thorough reviews and suggestions for the improvement of the manuscript. This work was supported by Antarctica New Zealand under the field event K053 "Cryosphere Remote Sensing" and by scholarships from the Christchurch City Council and the University of Canterbury for Nikolai Kruetzmann. The participation of Mette Riger-Kusk in the field work in 2008 is greatly acknowledged. The measurements were conducted within the ESA CryoSat-2 calibration and validation activities for project AOCRY2CAL-4512.

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1st AuthorKruetzmann, N.AuthorKruetzmann, N.Rack, W.McDonald, A.George, S.Year2011JournalCryosphereVolume5Number2Pages391-404DOI10.5194/tc-5-391-2011URLhttps://www.scopus.com/inward/recor.....1d31d2e4f9ba9e9ab9deccaa4Keywordscompactiondepth determinationground penetrating radarradar imagerysnow accumulationterrainwave reflectionwaveform analysis, AntarcticaEast AntarcticaRoss IslandScott Base, rank5

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TypeArticleCitationKruetzmann, N., Rack, W., McDonald, A. and George, S. (2011). Snow accumulation and compaction derived from GPR data near Ross Island, Antarctica. Cryosphere, 5(2): 391-404