CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 1

Model for Prediction Across Scales MPAS-Ocean

Climate, Ocean, Sea Ice Modeling Team (COSIM) Los Alamos National Laboratory

CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 2

MPAS-Ocean Overview

•  Horizontal variable resolution, global to regional modeling •  Mimetic primitive equation finite volume model. •  Vertical Arbitrary Lagrangian-Eulerian (ALE) coordinate:

supports z-level, z-star, sigma, idealized isopycnal •  High-order tracer conserving advection •  Mass conserving •  Idealized and realistic configurations •  Typical resolutions: 5 km to 120 km, 100 level, 1m surface •  Designed and tested for high performance computing •  New: ocean cavities below ice shelves

CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 3

MPAS-Ocean Publications •  Horizontal mesh and mimetic properties

–  TD Ringler, J Thuburn, JB Klemp, and WC Skamarock. A unified approach to energy conservation and potential vorticity dynamics for arbitrarily-structured C-grids. Journal of Computational Physics, 229(9):3065–3090, 2010.

–  W.C. Skamarock, J B Klemp, M G Duda, L D Fowler, S H Park, and T.˜D. Ringler. A multi-scale nonhydrostatic atmospheric model using centroidal Voronoi tesselations and Cgrid staggering. Monthly Weather Review, 140:3090–3105, 2012.

–  Todd D Ringler, Doug Jacobsen, Max Gunzburger, Lili Ju, Michael Duda, and William Skamarock. Exploring a Multiresolution Modeling Approach within the Shallow-Water Equations. Monthly Weather Review, 139(11):3348–3368, November 2011.

•  Global simulations –  Ringler, T., Petersen, M., Higdon, R.L., Jacobsen, D., Jones, P.W., Maltrud, M., 2013. A multi-resolution approach to global ocean

modeling. Ocean Modelling 69, 211-232.

•  Vertical ALE grid, idealized simulations –  Petersen, M.R., D. Jacobsen, T.D. Ringler, M.E. Maltrud, M. Hecht. (2015) Evaluation of the Arbitrary Langrangian-Eulerian vertical

coordinate in the MPAS-Ocean Model. Ocean Modelling 86, 93-113. –  Reckinger, S., Petersen, MR, Reckinger, S, (2015) A study of overflow simulations using MPAS-Ocean: Vertical grids, resolution, and

viscosity, Ocean Modelling, Volume 96, 291-313,

•  Analysis and parameterizations –  Juan A Saenz, Qingshan Chen, and Todd Ringler. Prognostic Residual Mean Flow in an Ocean General Circulation Model and its

Relation to Prognostic Eulerian Mean Flow. Journal of Physical Oceanography, 45(9):2247–2260, September 2015. –  Phillip J Wolfram, Todd D Ringler, Mathew E Maltrud, Douglas W Jacobsen, and Mark R Petersen. Diagnosing Isopycnal Diffusivity in

an Eddying, Idealized Midlatitude Ocean Basin via Lagrangian, in Situ, Global, High-Performance Particle Tracking (LIGHT). Journal of Physical Oceanography, 45(8):2114–2133, August 2015.

–  Woodring, J.; Petersen, M.; Schmeisser, A.; Patchett, J.; Ahrens, J.; Hagen, H., "In Situ Eddy Analysis in a High-Resolution Ocean Climate Model," in Visualization and Computer Graphics, IEEE Transactions on , vol.22, no.1, pp.857-866, Jan. 31 2016

CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 4

End-to-End Modeling System •  All functionality in single code base:

Ini'alcondi'ongenera'on

Modelconfigura'on(namelists)

PDESolver(ForwardModel)

AnalysistoolsandploNng

Automatedtes'ngandnightlyregressionsuite

CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 5

Software Practices •  Early discussion and review of new feature design •  Automated testing for Pull Requests and nightly regression •  Formal review process before feature merges to master •  Git repository for branches, Pull Request, and merge •  Documentation in code compiles into User’s Guide

DesignDocument

ReviewofDesign

Implementonbranch

Tes'ng:AutomatedRegressionsuite

PullRequestReview

Finalmergetomaster

CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 6

ACME Coupled Experience •  Accelerated Climate Model for Energy: V1 is running with

MPAS-Ocean, MPAS-Seaice, coupled with CIME •  CESM running with MPAS-Ocean C-Case (ocean only) in

two SciDAC projects •  Current simulations include

–  CORE-forced: data atmosphere and run-off –  Fully coupled: active atmosphere and land models

•  MPAS-Ocean & MPAS-Seaice on identical horizontal mesh •  MPAS-Seaice uses CICE column thermodynamics •  Analysis Capability:

–  In situ and post-processing tools on native MPAS mesh –  NCO regridding tool for structured-grid analysis (lat-lon grids)

CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 7

Objectives •  DOE resources directed towards ACME science goals •  NCAR resources directed towards CESM science goals •  Joint projects, where possible, will benefit both •  On joint projects, key is collaboration from design to review •  Minimize effort for major code merge projects

CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 8

Major Collaborations Already in Place •  MPAS framework is developed jointly with NCAR MMM •  MPAS code hosted in github repository shared with NCAR •  MPAS framework projects: Joint reviews of design and

pull requests include all parties (LANL and NCAR MMM)

DesignDocument

ReviewofDesign

Implementonbranch

Tes'ng:AutomatedRegressionsuite

PullRequestReview

Finalmergetomaster

•  ACME project is a community collaboration among DOE staff, university researchers, and NCAR scientists

CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 9

Vision of a Collaboration •  Proposal: Ocean Model Development Consortium •  LANL (DOE) and NCAR primary stakeholders •  Goal: where possible, work jointly from design to review

DesignDocument

ReviewofDesign

Implementonbranch

Tes'ng:AutomatedRegressionsuite

PullRequestReview

Finalmergetomaster

Newproject:FundingAgency,projectleaddecideifthisisindependentorjointdesign

CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 10

Collaboration and Independence •  At the beginning, projects could be put in one of five

development categories:

LANLonly

LANLLeadNCARsecondary

MutualLANL+NCAR

NCARLeadLANLsecondary

NCARonly

DOE/LANLpriori'es NCAR/NSFpriori'esSharedpriori'es

Op'onaljointreviewofdesignandcodebyLANLandNCARstaff

CESMMee'ng,Breckenridge,CO,June212016ResponsetoRFIforCESM3OceanModel 11

Collaborative Process •  Views expressed here are the consensus of LANL COSIM

members. •  Further discussion requires the involvement of

agency-level representation •  Details of code repository, design and review process

would be coordinated by Ocean Model Development Consortium

DesignDocument

ReviewofDesign

Implementonbranch

Tes'ng:AutomatedRegressionsuite

PullRequestReview

Finalmergetomaster

Newproject:FundingAgency,projectleaddecideifthisisindependentorjointdesign