A consistent data set of Antarctic ice sheet topography, cavity geometry, and global bathymetry

Timmermann, Ralph; Brocq, A. M. Le; Deen, T.; Domack, Eugene W.; Dutrieux, Pierre; Galton-Fenzi, B; Hellmer, Hartmut; Humbert, Angelika; Jansen, Daniela; Jenkins, Adrian; Lambrecht, Astrid; Makinson, Keith; Niederjasper, Fred; Nitsche, Frank; Nøst, Ole Anders; Smedsrud, Lars H.; Smith, Walter H. F.

doi:10.5194/essd-2-261-2010

Cited by 128 publications

(100 citation statements)

References 37 publications

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“…(8). The extent and importance of small-scale pinning is somewhat speculative, and deserves more study, observationally by examination of surface features or improved bathymetry (Horgan and Anandakrishnan, 2006;Fricker et al, 2009;Hulbe et al, 2010;Timmermann et al, 2010), and by modeling such as Favier et al (2012).…”

Section: Sub-grid Pinning Pointsmentioning

confidence: 99%

Description of a hybrid ice sheet-shelf model, and application to Antarctica

2012

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Abstract. The formulation of a 3-D ice sheet-shelf model is described. The model is designed for long-term continentalscale applications, and has been used mostly in paleoclimatic studies. It uses a hybrid combination of the scaled shallow ice and shallow shelf approximations for ice flow. Floating ice shelves and grounding-line migration are included, with parameterized ice fluxes at grounding lines that allows relatively coarse resolutions to be used. All significant components and parameterizations of the model are described in some detail. Basic results for modern Antarctica are compared with observations, and simulations over the last 5 million years are compared with previously published results. The sensitivity of ice volumes during the last deglaciation to basal sliding coefficients is discussed.

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Section: Sub-grid Pinning Pointsmentioning

confidence: 99%

Description of a hybrid ice sheet-shelf model, and application to Antarctica

2012

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“…The bathymetry in both simulations is based on RTopo-1 (Timmermann et al, 2010), and modified to include local high-resolution bathymetry as described in Mayet et al (2013). Ice draft of the MGT and B09B, along with the underlying bathymetry, is based on an early version of the most up-to-date product by Mayet et al (2013).…”

Section: Environmental Data and Numerical Modeling Ocean Model And Bamentioning

confidence: 99%

Mapping Antarctic Suspension Feeder Abundances and Seafloor Food-Availability, and Modeling Their Change After a Major Glacier Calving

et al. 2018

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Seafloor communities are a critical part of the unique and diverse Antarctic marine life. Processes at the ocean-surface can strongly influence the diversity and abundance of these communities, even when they live at hundreds of meters water depth. However, even though we understand the importance of this link, there are so far no quantitative spatial predictions on how seafloor communities will respond to changing conditions at the ocean surface. Here, we map patterns in abundance of important habitat-forming suspension feeders on the seafloor in East Antarctica, and predict how these patterns change after a major disturbance in the icescape, caused by the calving of the Mertz Glacier Tongue. We use a purpose-built ocean model for the time-period before and after the calving of the Mertz-Glacier Tongue in 2010, data from satellites and a validated food-availability model to estimate changes in horizontal flux of food since the glacier calving. We then predict the post-calving distribution of suspension feeder abundances using the established relationships with the environmental variables, and changes in horizontal flux of food. Our resulting maps indicate strong increases in suspension feeder abundances close to the glacier calving site, fueled by increased food supply, while the remainder of the region maintains similar suspension feeder abundances despite a slight decrease in total food supply. The oceanographic setting of the entire region changes, with a shorter ice-free season, altered seafloor currents and changes in food-availability. Our study provides important insight into the flow-on effects of a changing icescape on seafloor habitat and fauna in polar environments. Understanding these connections is important in the context of current and future effects of climate change, and the mapped predictions of the seafloor fauna as presented for the study region can be used as a decision-tool for planning potential marine protected areas, and for focusing future sampling and monitoring initiatives.

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“…On the other hand, some of the narrow straits that are important to the global thermohaline circulation (e.g., Fram and Denmark Straits, and the region between Iceland and Scotland) are represented with high resolution (TWH12). Ice shelf draft, cavity geometry, and global ocean bathymetry have been derived from the RTopo-1 dataset (Timmermann et al, 2010) and thus consider data from many of the most recent surveys of the Antarctic continental shelf.…”

Section: Model Descriptionmentioning

confidence: 99%

Southern Ocean warming and increased ice shelf basal melting in the twenty-first and twenty-second centuries based on coupled ice-ocean finite-element modelling

2013

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We utilize a global finite element sea ice -ice shelf -ocean model (FESOM), focused on the Antarctic marginal seas, to analyse projections of ice shelf basal melting in a warmer climate. Ice shelf -ocean interaction is described using a three-equation system with a diagnostic computation of temperature and salinity at the ice-ocean interface. A tetrahedral mesh with a minimum horizontal resolution of 4 km and hybrid vertical coordinates is used. Ice shelf draft, cavity geometry, and global ocean bathymetry have been derived from the RTopo-1 data set. The model is forced with the atmospheric output from two climate models: (1) the Hadley Centre Climate Model (HadCM3) and (2) Max Planck Institute's ECHAM5/MPI-OM coupled climate model. Results from experiments forced with their 20th-century output are used to evaluate the modeled present-day ocean state. Sea-ice coverage is largely realistic in both simulations; modeled ice shelf basal melt rates compare well with observations in both cases, but are consistently smaller for ECHAM5/MPI-OM. Projections for future ice shelf basal melting are computed using atmospheric output for the IPCC scenarios E1 and A1B. In simulations forced with ECHAM5 data, trends in ice shelf basal melting are small. In contrast, decreasing convection along the Antarctic coast in HadCM3 scenarios leads to a decreasing salinity on the continental shelf and to intrusions of warm deep water of open ocean origin. In case of Filchner-Ronne Ice Shelf (FRIS), this water reaches deep into the cavity, so that basal melting increases by a factor of four to six compared to the present value of about 90 Gt/yr.

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A consistent data set of Antarctic ice sheet topography, cavity geometry, and global bathymetry

Cited by 128 publications

References 37 publications

Description of a hybrid ice sheet-shelf model, and application to Antarctica

Description of a hybrid ice sheet-shelf model, and application to Antarctica

Mapping Antarctic Suspension Feeder Abundances and Seafloor Food-Availability, and Modeling Their Change After a Major Glacier Calving

Southern Ocean warming and increased ice shelf basal melting in the twenty-first and twenty-second centuries based on coupled ice-ocean finite-element modelling

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