Difference between revisions of "Higher order velocity schemes"

From Interactive System for Ice sheet Simulation
Jump to: navigation, search
Line 1: Line 1:
 
==Higher-Order model basics==
 
==Higher-Order model basics==
The main distinction between so-called "higher-order" models and "0-order" (or "shallow ice") models is that higher-order models attempt a closer approximation to solving the non-linear, full [[Stokes system of equations]]. In general, this usually means incorporating some approximation of horizontal-stress gradients; along-flow stretching or compression and across-flow shearing.
+
The main distinction between so-called "higher-order" models and "0-order" (or "shallow ice") models is that higher-order models attempt a closer approximation to solving the non-linear, [[Stokes equations]]. In general, this usually means incorporating some approximation of horizontal-stress gradients; along-flow stretching or compression and across-flow shearing.
  
  

Revision as of 12:58, 30 July 2009

Higher-Order model basics

The main distinction between so-called "higher-order" models and "0-order" (or "shallow ice") models is that higher-order models attempt a closer approximation to solving the non-linear, Stokes equations. In general, this usually means incorporating some approximation of horizontal-stress gradients; along-flow stretching or compression and across-flow shearing.


shallow

  • HO model; what distinguishes it from a LO model, why is it useful.
  • Available HO schemes (e.g. Full Stokes, Blatter-Pattyn, Bueler & Pollard Hybrids)
  • Architecture (transport, and non-linear iteration on diffusivity) of Glimmer an how it differs from a HO model architecture
  • Introduce HO CISM (Blatter-Pattyn 1st-order scheme)
  • Discretization and solution (elliptic solve, operator splitting approach, etc)
  • Boundary conditions + masking, one sided differences, basal BC (no-slip, viscous, and plastic behavior all through Beta^2 implementation)
  • Run verification suites; ISMIP-HOM, Ross IS
  • Apply HO velocity fields to 1st-order upwind transport (dH/dt) scheme (see Adding a module to Glimmer I)