Airborne-radar and ice-core observations of annual snow accumulation over Thwaites Glacier, West Antarctica confirm the spatiotemporal variability of global and regional atmospheric models

• Published in: Geophysical Research Letters
• Main Authors: Medley, Brooke, Joughin, Ian, Das, Sarah B., Steig, Eric J., Conway, Howard, Gogineni, S., Criscitiello, Alison S., McConnell, Joseph R., Smith, B. E., van den Broeke, Michiel R., Lenaerts, Jan T. M., Bromwich, D. H., Nicolas, J. P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: John Wiley & Sons 2013
• Subjects: West Antarctica; Snow accumulation; Airborne radar; Firn; Thwaites Glacier; Antarc*; Antarctica; ice core
• Online Access: https://hdl.handle.net/1912/6234

Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 40 (2013): 3649–3654, doi:10.1002/grl.50706. We use an airborne-radar method, verified with ice-core accumulation records, to determine the spatiotemporal variations of snow accumulation over Thwaites Glacier, West Antarctica between 1980 and 2009. We also present a regional evaluation of modeled accumulation in Antarctica. Comparisons between radar-derived measurements and model outputs show that three global models capture the interannual variability well (r > 0.9), but a high-resolution regional model (RACMO2) has better absolute accuracy and captures the observed spatial variability (r = 0.86). Neither the measured nor modeled accumulation records over Thwaites Glacier show any trend since 1980. Although an increase in accumulation may potentially accompany the observed warming in the region, the projected trend is too small to detect over the 30 year record. This research was supported at UW by NSF OPP grants ANT-0631973 (B.M., I.J., E.J.S., and H.C.) and ANT-0424589 (B.M. and I.J.) and at WHOI by ANT-0632031 (S.B.D. and A.S.C.). D.H.B. and J.P.N. were supported by NASA grant NN12XAI29G. We acknowledge the work by the CReSIS team that went into developing the snow-radar system, which was partially supported with by NASA grant NNX10AT68G and by NSF OPP grant ANT-0424589 awarded to S.P. 2014-01-26