Hostname: page-component-76fb5796d-qxdb6 Total loading time: 0 Render date: 2024-04-26T07:12:10.662Z Has data issue: false hasContentIssue false

Firn depth correction along the Antarctic grounding line

Published online by Cambridge University Press:  25 June 2008

Michiel van den Broeke*
Affiliation:
Institute for Marine and Atmospheric Research (IMAU), Utrecht University, The Netherlands
Willem Jan van de Berg
Affiliation:
Institute for Marine and Atmospheric Research (IMAU), Utrecht University, The Netherlands
Erik van Meijgaard
Affiliation:
Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands

Abstract

To reduce the uncertainty in the calculation of Antarctic solid ice fluxes, the firn depth correction (Δh) in Antarctica is inferred from a steady-state firn densification model forced by a regional atmospheric climate model. The modelled density agrees well with observations from firn cores, apart from a site at the origin of fast flowing West Antarctic ice stream (Upstream B), where densification is anomalously rapid. The spatial distribution of Δh over Antarctica shows large variations, especially in the grounding line zone where large climate gradients exist. In places where the grounding line crosses ablation areas, Δh is zero. Along the remainder of the grounding line, Δh values range from typically 13 m in dry coastal areas (e.g. Dronning Maud Land) to 19 m in wet coastal areas (e.g. West Antarctica).

Type
Physical Sciences
Copyright
Copyright © Antarctic Science Ltd 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alley, R.B. & Bentley, C.R. 1988. Ice-core analysis on the Siple coast of West Antarctica. Annals of Glaciology, 11, 17.CrossRefGoogle Scholar
Arnaud, L., Lipenkov, V.Y., Barnola, J.-M., Gay, M. & Duval, P. 1998. Modelling of the densification of polar firn: characterization of the snow-firn transition. Annals of Glaciology, 26, 3944.CrossRefGoogle Scholar
Bamber, J. & Gomez-Dans, J.-L. 2005. The accuracy of digital elevation models of the Antarctic continent. Earth Planetary Science Letters, 237, 516523.CrossRefGoogle Scholar
Barnola, J.-M., Pimienta, P., Raynaud, D. & Korotkevich, Y.S. 1991. CO2 climate relationship as deduced from the Vostok ice core: a re-evaluation of the air dating. Tellus, 43B, 8390.CrossRefGoogle Scholar
Craven, M. & Allison, I. 1998. Firnification and the effects of wind-packing on Antarctic snow. Annals of Glaciology, 27 239245.CrossRefGoogle Scholar
Herron, M. & Langway, C. Jr 1980. Firn densification: an empirical model. Journal of Glaciology, 25, 373385.CrossRefGoogle Scholar
Kameda, T., Shoji, H., Kawada, K., Watanabe, O. & Clausen, H.B. 1994. An empirical relation between overburden pressure and firn density. Annals of Glaciology, 20, 8794.Google Scholar
Kaspers, K.A., van de Wal, R.S.W., van den Broeke, M.R., van Lipzig, N.P.M. & Brenninkmeijer, C.A.M. 2004. Model calculations of the age of firn air across the Antarctic continent. Atmospheric Chemistry and Physics, 4, 18171853.Google Scholar
Li, J. & Zwally, H.J. 2004. Modeling the density variation in the shallow firn layer. Annals of Glaciology, 38, 303313.CrossRefGoogle Scholar
Pimienta, P. & Duval, P. 1987. Rate controlling processes in the creep of polar glacier ice. Journal de Physique, 48, 243248.Google Scholar
Rignot, E., Bamber, J.L., van den Broeke, M.R., Davis, C., Li, Y., van de Berg, W.J. & van Meijgaard, E. 2008. Recent Antarctic mass loss from radar interferometry and regional climate modelling. Nature Geoscience, 2, 106110.CrossRefGoogle Scholar
Reijmer, C.H., van Meijgaard, E. & van den Broeke, M.R. 2005. Evaluation of temperature and wind over Antarctica in a regional atmospheric climate model. Journal of Geophysical Research, 110, 10.1029/2004JD005234.CrossRefGoogle Scholar
Spencer, M.K., Alley, R.B. & Creyts, T.T. 2001. Preliminary firn-densification model with 38-site dataset. Journal of Glaciology, 47, 671676CrossRefGoogle Scholar
Van Lipzig, N.P.M., Turner, J., Colwell, S.R. & van den Broeke, M.R. 2004. The near-surface wind field over the Antarctic continent. International Journal of Climatology, 24, 19731982.CrossRefGoogle Scholar
Van de Berg, W.J., van den Broeke, M.R., van Meijgaard, E. & Reijmer, C.H. 2006. Reassessment of the Antarctic surface mass balance using calibrated output of a regional atmospheric climate model. Journal of Geophysical Research, 111, 10.1029/2006JD007127.CrossRefGoogle Scholar
Van den Broeke, M.R. 2008. Depth and density of the Antarctic firn layer. Arctic, Antarctic and Alpine Research, 40.CrossRefGoogle Scholar
Van den Broeke, M.R., van de Berg, W.J., van Meijgaard, E. & Reijmer, C.H. 2006. Identification of Antarctic ablation areas using a regional atmospheric climate model. Journal of Geophysical Research, 111, 10.1029/2006JD007127.CrossRefGoogle Scholar
Vaughan, D.G., Bamber, J.L., Giovinetto, M. & Cooper, A.P.R. 1999. Reassessment of net surface mass balance in Antarctica. Journal of Climatology, 12, 933946.2.0.CO;2>CrossRefGoogle Scholar
Winther, J.-G., Jespersen, M.N. & Liston, G.E. 2001. Blue-ice areas in Antarctica derived from NOAA AVHRR satellite data. Journal of Glaciology, 47, 325334.CrossRefGoogle Scholar
Zwally, H.J., Giovinetto, M.B., Li, J., Cornejo, H.G., Beckley, M.A., Brenner, A.C., Saba, J.L. & Yi, D. 2005. Mass changes of the Greenland and Antarctic ice sheets and shelves and contributions to sea-level rise: 1992–2002. Journal of Glaciology, 51, 509527.CrossRefGoogle Scholar