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The Design Document page provides a description of the algorithms, implementation and planned testing including unit, verification, validation and performance testing. Please read  Step 1.3 Performance Expectations that explains feature documentation requirements from the performance group point of view. 

Design Document

 

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The first table in Design Document gives overview of this document, from this info the Design Documents Overview page is automatically created.

In the table below, 4.Equ means Equations and Algorithms, 5.Ver means Verification, 6.Perf - Performance, 7. Val - Validation

  • Equations: Document the equations that are being solved and describe algorithms
  • Verification Plans: Define tests that will be run to show that implementation is correct and robust. Involve unit tests to cover range of inputs as well as benchmarks.
  • Performance expectations: Explain the expected performance impact from this development
  • Validation Plans: Document what process-based, stand-alone component, and coupled model runs will be performed, and with what metrics will be used to assess validity

Use the symbols below (copy and paste) to indicate if the section is in progress or done or not started.

In the table below, 4.Equ means Equations and Algorithms, 5.Ver means Verification, 6.Perf - Performance, 7. Val - Validation,   (tick) - completed, (warning) - in progress, (error) - not done

 

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Overview table for the owner and an approver of this feature

1.Description

 
2.OwnerStephen Price
3.Created 
4.Equ(warning)
5.Ver(warning)
6.Perf(warning)
7.Val(warning)
8.Approver 
9.Approved Date 

 

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Table of Contents

Table of Contents

 

 


 


Title: O_24_LI MPAS Land Ice in ACME Design Doc

Requirements and Design

ACME Ocean and Ice Group

Date: 2015-9-23

Summary

A three dimensional, thermo-mechanical ice sheet model, implemented in the MPAS -Land Ice modeling framework, will be coupled to ACME. The model itself is more fully described elsewhere, including extensive verification and performance testing (see additional discussion below and in the references at the bottom of this document). This document describes the model at a high - level requirements and design for the process of integrating that model into with a focus on development and verifciation of new features added under ACME.


Requirements


Requirement:

Support for Trilinos and Albany third-party libraries in ACME

Conservation of mass, energy, and momentum

Date last modified:  2015-9-23
Contributors: Stephen Price

The MPAS Land Ice model requires linking to an "external dycore", the FELIX-Albany dycore developed under the PISCEES project (Tezuar et al., 2015a; 2015b, below). The dycore is built using the the Trilinos and Albany software libraries, which therefor must be made available to the ACME build system.  

Requirement: blah

land ice model will conserve mass, energy, and momentum.



Requirement: Accurate marine ice sheet dynamics


Date last modified:  2015-9-23
Contributors: Stephen Price

The momentum and mass conservation components of the dynamical core will provide an accurate simulation of marine ice sheet dynamics. Specifically, the simulation of retreat and advance of the grounding line (position at which ice goes afloat due to buoyancy) will be verified according to standard benchmark test cases.

Requirement: Iceberg calving

Date last modified:  2015-9-23
Contributors: Stephen Price

The momentum and mass conservation components of the dynamical core will allow for the retreat and advance of floating ice margins (the fronts of ice shelves) through the implementation of iceberg "calving" physics.

Requirement:

blah

Support for optimal initial conditions


Date last modified:  2015-9-23 
Contributors: Stephen Price

The initial condition for the ice sheet model should be both a good representation of present-day observations of the ice sheet state (e.g., the geometry and velocity fields) and should be approximately equilibrated with present-day forcing from the climate model (in order to avoid undesirable ice sheet model transients that could mask actual trends of interest).


Algorithmic Formulations 

Design solution: N/A

Date last modified:  2015-9-23
Contributors: Stephen Price
The design solutions are primarily software and build-system related and as such, do not require any particular algorithmic solutions

Algorithmic formulations for all of the above requirements are discussed in their respective design documents, already published paper, or existing model documentation (referenced as appropriate in the design solutions / implementation sections below).



Design and Implementation

Implementation: Support for

Trilinos and Albany third-party libraries in ACME

optimal initial conditions

Date last modified:  2015-9-23
Contributors: Stephen Price

This item is covered by the code review item O_21_LI Third Party Support for MPAS-LI within ACME Design DocumentBecause of the long timescales associated with equilibrium of processes internal to ice sheets (primarily thermal equilibration), standard climate model "spin up" methods are problematic for ice sheet models in terms of providing optimal initial conditions and / or initial conditions that are in quasi-equlibrium with a given climate forcing. For a number of reasons (discussed in detail in Perego et al., 2014), these goals are best addressed through formal, adjoint-based optimization methods. A brief discussion of the approach is given in the design document here. In general, we are implementing methods pioneered under the PISCEES project and discussed in Perego et al. (2014).


 

 

 

Planned Verification and Unit Testing 

Verification and Unit Testing: short-desciption-of-testing-here

Date last modified:  
Contributors: (add your name to this list if it does not appear)

 


How will XXX be tested? i.e. how will be we know when we have met requirement XXX. Will these unit tests be included in the ongoing going forward?

 


Planned Validation Testing 

Validation Testing: short-desciption-of-testing-here

Date last modified:  
Contributors: (add your name to this list if it does not appear)

 

 

How will XXX be tested? What observational or other dataset will be used?  i.e. how will be we know when we have met requirement XXX. Will these unit tests be included in the ongoing going forward?

 

 

Planned Performance Testing


Performance Testing: short-desciption-of-testing-here

Date last modified:  
Contributors: (add your name to this list if it does not appear)

 

 

How will XXX be tested? i.e. how will be we know when we have met requirement XXX. Will these unit tests be included in the ongoing going forward?

 



References

  • Perego, M., S. Price, and G. Stadler, 2014: Optimal initial conditions for coupling ice sheet models to Earth system models. … of Geophysical Research: Earth …, doi:10.1002/(ISSN)2169-9011.
     
  • Tezaur, I., M. Perego, A. Salinger, R. Tuminaro, and S. Price. 2015a. Albany/FELIX: a parallel, scalable and robust, finite element, first-order Stokes approximation ice sheet solver built for advanced analysis, Geophys. Model Devel., 8, doi:10.5194/gmd-8-1197-2015. link
  • Tezaur, I., R. Tuminaro, M. Perego, A. Salinger, S. Price, 2015b: On the scalability of the Albany/FELIX first-order Stokes approximation ice sheet solver for large-scale simulations of the Greenland and Antarctic ice sheets", Numerical and Computational Developments to Advance Multiscale Earth System Models (MSESM)/International Conference on Computational Science (ICCS15), Reykjavik, Iceland link
  • MPAS Land Ice Model User's Guide Version 3.0. link