A consistent data set of Antarctic ice sheet topography, cavity geometry, and global bathymetry R. Timmermann1, A. Le Brocq2, T. Deen3, E. Domack4, P. Dutrieux3, B. Galton-Fenzi5, H. Hellmer1, A. Humbert6, D. Jansen7, A. Jenkins3, A. Lambrecht8, K. Makinson3, F. Niederjasper1, F. Nitsche9, O. A. Nøst10, L. H. Smedsrud11, and W. H. F. Smith12 1Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany 2University of Exeter, Exter, UK 3British Antarctic Survey, Cambridge, UK 4Hamilton College, Clinton, NY, USA 5University of Tasmania, Hobart, Tasmania 6KlimaCampus, University of Hamburg, Hamburg, Germany 7Swansea University, Swansea, UK 8University Innsbruck, Innsbruck, Austria 9Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA 10Norwegian Polar Institute, Tromsø, Norway 11Bjerknes Centre for Climate Research, Bergen, Norway 12Laboratory for Satellite Altimetry, NOAA NESDIS, Silver Spring, MD, USA
Abstract. Sub-ice shelf circulation and freezing/melting rates in ocean general
circulation models depend critically on an accurate and consistent
representation of cavity geometry. Existing global or pan-Antarctic topography data sets
have turned out to contain various inconsistencies and inaccuracies. The goal
of this work is to compile independent regional surveys and maps into a global data
set. We use the S-2004 global 1-min bathymetry as the backbone and add an
improved version of the BEDMAP topography (ALBMAP bedrock topography) for an
area that roughly coincides with the Antarctic continental shelf. The
position of the merging line is individually chosen in different sectors in
order to capture the best of both data sets. High-resolution gridded data for
ice shelf topography and cavity geometry of the Amery,
Fimbul, Filchner-Ronne, Larsen C and George VI Ice Shelves, and for Pine
Island Glacier are carefully merged into the ambient ice and ocean
topographies. Multibeam survey data for bathymetry in the former Larsen B
cavity and the southeastern Bellingshausen Sea have been obtained from the
data centers of Alfred Wegener Institute (AWI), British Antarctic Survey
(BAS) and Lamont-Doherty Earth Observatory (LDEO), gridded, and blended into
the existing bathymetry map. The resulting global 1-min Refined Topography data
set (RTopo-1) contains self-consistent maps for upper and lower ice surface heights,
bedrock topography, and surface type (open ocean, grounded ice, floating ice, bare land surface).
The data set is available in NetCDF format from the
PANGAEA database at doi:10.1594/pangaea.741917.
Citation: Timmermann, R., Le Brocq, A., Deen, T., Domack, E., Dutrieux, P., Galton-Fenzi, B., Hellmer, H., Humbert, A., Jansen, D., Jenkins, A., Lambrecht, A., Makinson, K., Niederjasper, F., Nitsche, F., Nøst, O. A., Smedsrud, L. H., and Smith, W. H. F.: A consistent data set of Antarctic ice sheet topography, cavity geometry, and global bathymetry, Earth Syst. Sci. Data, 2, 261-273, doi:10.5194/essd-2-261-2010, 2010.