C06 Ice Sheet and Ocean Interactions on Multiple Scales

IACS (Cryosphere)



28-Jun-2015, 08:30 - 10:00


 
Abstract content:

Coupled ice sheet-ocean simulations with the POPSICLES model

We present idealized and realistic simulations using the POPSICLES coupled ice sheet-ocean model. POPSICLES couples the POP2x ocean model—a modified version of the Parallel Ocean Program (Smith and Gent, 2002)—and the BISICLES ice-sheet model (Cornford et al., 2012). POP2x includes sub-ice-shelf circulation using partial top cells (Losch, 2008) and boundary layer physics following Holland and Jenkins (1999) and others. BISICLES makes use of adaptive mesh refinement and a momentum balance similar to the L1L2 model of Schoof and Hindmarsh (2009) to accurately model regions of dynamic complexity, such as ice streams, outlet glaciers, and grounding lines.

We show that POPSICLES produces similar results to Goldberg et al. (2012a,b) in an idealized setup comparable to Pine Island Glacier/Ice Shelf. We present results from a new set of idealized, coupled experiments, the Marine Ice Sheet-Ocean Model Intercomparison Project (MISOMIP). We propose the MISOMIP experiments, together with their standalone ocean (ISOMIP+) and ice-sheet (MISMIP+) companions as standard test cases for coupled ice sheet-ocean models.

In a realistic configuration, our POPSICLES simulations cover the full Antarctic Ice Sheet and the Southern Ocean and span the period 1990 to 2010. Simulations are performed at 0.1 deg. (~5 km) ocean resolution and with adaptive ice-sheet model resolution as fine as 500 m. We explore the influence on basal melting and system dynamics resulting from two different choices of climate forcing: a mean climatology and the interannually varying CORE v. 2 forcing data (Large and Yeager 2008). We also point out the influence of uncertainties in ice shelf cavity thickness (due to a lack of observations of sub-ice-shelf bathymetry) on melt rates and grounding-line dynamics.

 
Author(s):
X. Asay-Davis1, D. Martin2, S. Cornford3, S. Price4, W. Collins5.
1Potsdam Institute for Climate Impact Research, Earth System Analysis, Potsdam, Germany.
2Lawrence Berkeley National Laboratory, Applied Numerical Algorithms Group, Berkeley- CA, USA.
3University of Bristol, School of Geographical Sciences, Bristol, United Kingdom.
4Los Alamos National Laboratory, Fluid Dynamics and Solid Mechanics Group, Los Alamos- NM, USA.
5Lawrence Berkeley National Laboratory, Climate Science Department, Berkeley- CA, USA.

 

Keywords:
ice-ocean interactions     ice-sheet modeling     ocean modeling     Antarctica