NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH C. DeLuca/NCAR, J. Anderson/NCAR, V. Balaji/GFDL, B. Boville/NCAR, N. Collins/NCAR,

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH

C. DeLuca/NCAR, J. Anderson/NCAR, V. Balaji/GFDL, B. Boville/NCAR, N. Collins/NCAR, T. Craig/NCAR, C. Cruz/GSFC, A. da Silva/GSFC, R. Hallberg/GFDL, C. Hill/MIT, M. Iredell/NCEP, R. Jacob/ANL, P. Jones/LANL, B. Kauffman/NCAR, J. Larson/ANL, J. Michalakes/NCAR, E. Schwab/NCAR, S. Smithline/GFDL, Q. Stout/U Mich, M. Suarez/GSFC, A. Trayanov/GSFC, S. Vasquez/NCAR, J. Wolfe/NCAR, W. Yang/NCEP, M. Young/NCEP and L. Zaslavsky/GSFC

Introduction to the Earth System Modeling Framework

NSIPP Seasonal Forecast

NCAR/LANL CCSM NCEP ForecastGFDL FMS Suite

MITgcmNASA GSFC PSASClimate

Data Assimilation

Weather


Outline

• ESMF Overview• ESMF Applications• Related Projects• ESMF Architecture• Timeline


Background

NASA’s Earth Science Technology Office proposed the creation of anEarth System Modeling Framework (ESMF) in the September 2000 NASA Cooperative Agreement Notice:

“Increasing Interoperability and Performance of Grand Challenge Applications in the Earth, Space, Life and Microgravity Sciences”

A large, interagency collaboration with roots in the Common Modeling Infrastructure Working Group proposed three interlinked projects to develop and deploy the ESMF, which were all funded:

Part I: Core ESMF Development (PI: Killeen, NCAR)Part II: Modeling Applications (PI: Marshall, MIT)Part III: Data Assimilation Applications (PI: da Silva, NASA GMAO)


Motivation

In climate research and NWP... increased emphasis on detailed representation of individual physical processes; requires many teams of specialists to contribute components to an overall modeling system

In computing technology... increase in hardware and software complexity in high-performance computing, as we shift toward the use of scalable computing architectures

In software …development of frameworks, such as FMS, GEMS, CCA and WRF, that encourage software reuse and interoperability

The ESMF is a focused community effort to tame the complexity of models and

the computing environment. It leverages, unifies and extends existing software

frameworks, creating new opportunities for scientific contribution and collaboration.


ESMF Project DescriptionGOALS: To increase software reuse, interoperability, ease of use and performance portability in

climate, weather, and data assimilation applications

PRODUCTS: • Core framework: Software for coupling geophysical components and utilities for building

components • Applications: Deployment of the ESMF in 15 of the nation’s leading climate and weather

models, assembly of 8 new science-motivated applications

METRICS:

RESOURCES and TIMELINE: $9.8M over 3 years

Reuse Interoperability Ease of Adoption Performance

15 applications use ESMF component coupling services and 3+ utilities

8 new applications comprised of never-before coupled components

2 codes adopt ESMF with < 2% lines of code changed, or within 120 FTE-hours

No more than 10% overhead in time to solution, no degradation in scaling


ESMF Accelerates Advances in Earth System Science

Eliminates software barriers to collaboration among organizations• Easy exchange of model components accelerates progress in NWP and climate

modeling• Independently developed models and data assimilation methods can be combined and

tested• Coupled model development becomes a truly distributed process• Advances from smaller academic groups easily adopted by large modeling centers

Facilitates development of new interdisciplinary collaborations• Simplifies extension of climate models to upper atmosphere• Accelerates inclusion of advanced biogeochemical components into climate models• Develops clear path for many other communities to use, improve, and extend climate

models• Many new model components gain easy access to power of data assimilation


ESMF Collaborators

NSF NCARTim Killeen, PIJeff Anderson Byron BovilleNancy Collins Cecelia DeLucaRoberta JohnsonAl KellieJohn MichalakesDavid NeckelsEarl Schwab Robbie StauferSilverio Vasquez Jon Wolfe

DOE ANLRob JacobJay Larson

NOAA GFDLAnts LeetmaaV. BalajiRobert HallbergShep Smithline

NASA GMAOArlindo da Silva, PIMichele RieneckerMax SuarezAtanas TrayanovChristian KeppenneLeonid ZaslavskyWill SawyerCarlos Cruz

NOAA NCEPStephen LordMark IredellMike YoungWeiyu YangJohn Derber

MITJohn Marshall, PIChris Hill

DOE LANLPhil Jones

University of MichiganQuentin Stout


Outline



Modeling Applications

SOURCE APPLICATION

GFDL FMS B-grid atmosphere at N45L18

FMS spectral atmosphere at T63L18

FMS MOM4 ocean model at 2°x2°xL40

FMS HIM isopycnal C-language ocean model at 1/6°x1/6°L22

MIT MITgcm coupled atmosphere/ocean at 2.8°x2.8°, atmosphere L5, ocean L15

MITgcm regional and global ocean at 15kmL30

GMAO/NSIPP NSIPP atmospheric GCM at 2°x2.5°xL34 coupled with NSIPP ocean GCM at 2/3°x1.25°L20

NCAR/LANL CCSM2 including CAM with Eulerian spectral dynamics and CLM at T42L26 coupled with POP ocean and data ice model at 1°x1°L40


Data Assimilation Applications

SOURCE APPLICATION

GMAO/DAO PSAS interface layer with 2O0K observations/day

CAM with finite volume dynamics at 2°x2.5°L55, including CLM

NCEP Global atmospheric spectral model at T170L42

SSI analysis system with 250K observations/day, 2 tracers

WRF regional atmospheric model at 22km resolution CONUS forecast 345x569L50

GMAO/NSIPP ODAS with OI analysis system at 1.25°x1.25°L20 resolution with ~10K observations/day

MIT MITgcm 2.8° century / millennium adjoint sensitivity


Interoperability Experiments:8 New Applications

COUPLED CONFIGURATION NEW SCIENCE ENABLED

GFDL B-grid atm / MITgcm ocn Global biogeochemistry (CO2, O2), SI timescales.

GFDL MOM4 / NCEP forecast NCEP seasonal forecasting system.

NSIPP ocean / LANL CICE Sea ice model for extension of SI system to centennial time scales.

NSIPP atm / DAO analysis Assimilated initial state for SI.

DAO analysis / NCEP model Intercomparison of systems for NASA/NOAA joint center for satellite data assimilation.

DAO CAM-fv / NCEP analysis Intercomparison of systems for NASA/NOAA joint center for satellite data assimilation.

NCAR CAM Eul / MITgcm ocn Improved climate predictive capability: climate sensitivity to large component interchange, optimized initial conditions.

NCEP WRF / GFDL MOM4 Development of hurricane prediction capability.


Outline



Related Projects

• PRISM is an ongoing European Earth system modeling infrastructure project

• Involves current state-of-the-art atmosphere, ocean, sea-ice, atmospheric chemistry, land-surface and ocean-biogeochemistry models

• 22 partners: leading climate researchers and computer vendors, includes MPI, KNMI, UK Met Office, CERFACS, ECMWF, DMI

• ESMF is working with PRISM to mergeframeworks and develop common conventions

• CCA is creating a minimal interface and sets of tools for linking high performance components. CCA can be used to implement frameworks and standards developed in specific domains (such as ESMF).

• Collaborators include LANL, ANL, LLNL, ORNL, Sandia, University of Tennessee, and many more. Ongoing ESMF collaboration with CCA/LANL on language interoperability.

• Working prototype demonstrating CCA/ESMF interoperability, to be presented at SC2003.

For joint use with PRISM, ESMFdeveloped a component databaseto store component import/export fields and component descriptions

For joint use with PRISM, ESMFdeveloped a component databaseto store component import/export fields and component descriptions


ESMF Connections

Larson/ANLDeLuca/NCAR-SCDJones/LANLStout/U MichKilleen/NCARDrake/ORNLBoville/NCAR-CGDMichalakes/NCAR-MMMSuarez/NASA GoddardBalaji/NOAA GFDL

CCA

WRF

SciDAC

CCSM

GEMSFMSSWMF

PRISM

ESMF

ESMF Earth System Modeling FrameworkCCA DOE Common Component ArchitectureSciDAC DOE/NSF CCSM SciDAC ProjectGEMS Goddard Earth Modeling SystemFMS GFDL Flexible Modeling SystemSWMF Space Weather Modeling FrameworkWRF Weather Research and Forecast ModelCCSM Community Climate System ModelPRISM Program for Int. Earth System Modeling


Outline



Computational Characteristicsof Weather/Climate• Mix of global transforms and local communications• Load balancing for diurnal cycle, event (e.g. storm) tracking• Applications typically require 10s of GFLOPS,

100s of PEs – but can go to 10s of TFLOPS, 1000s of PEs• Required Unix/Linux platforms span laptop to

Earth Simulator• Multi-component applications: component

hierarchies, ensembles, and exchanges• Data and grid transformations between

components • Applications may be MPMD/SPMD,

concurrent/sequential, combinations • Parallelization via MPI, OpenMP, shmem, combinations• Large applications (typically 100,000+ lines of source code)

Platforms

assim

sea iceocean

landatm

physics dycore

assim_atm

atmland

Seasonal Forecastcoupler


Architecture

Low Level Utilities

Fields and Grids Layer

Model Layer

Components Layer:Gridded ComponentsCoupler Components

ESMF Infrastructure

User Code

ESMF Superstructure

BLAS, MPI, NetCDF, …External Libraries

1. ESMF provides an environment for assembling geophysical components into applications.

2. ESMF provides a toolkit that components use to

i. increase interoperability

ii. improve performance portability

iii. abstract common services

Becoming an ESMF Component• Pack model import and export data into ESMF data structures and conform to a standard

calendar. Use ESMF utilities internally as desired. Organize model using standard ESMF methods: Initialize, Run, Finalize, ReadRestart, WriteRestart. Methods may be multi-phase (Run phase=1, Run phase=2). Method interfaces are prescribed.

• Instantiate an ESMF Component with name, type, config information. Register standard model methods with Component. If desired, register data.

• Use ESMF AppDriver to sequence and run Components.


Design Features

ESMF enables modeling applications to be:• Scalable

Models are built from modular components, and can be easily nested within larger applications

• Performance - portable ESMF high-performance communication libraries offer a consistent interface across computer architectures

• Exchangeable Standard component interfaces enable interoperability


ESMF Class Structure

DELayoutCommunications

StateData imported or exported

BundleCollection of fields

GridCompLand, ocean, atm, … model

F90

Superstructure

Infrastructure

FieldPhysical field, e.g. pressure

GridLogRect, Unstruct, etc.

Data Communications

C++

RegridComputes interp weights

CplCompXfers between GridComps

UtilitiesMachine, TimeMgr, LogErr, I/O, Config, Base etc.

ArrayHybrid F90/C++ arrays Route

Stores comm paths

DistGridGrid decomposition

PhysGridMath description


Design Principle:Local CommunicationAll inter-Component communication within ESMF is local - all communication is handled within Components. This allows the architecture of the framework to be independent of the communication strategy.

climate_comp

ocn_comp atm_comp

atm_phys

phys2dyn_coupler

atm_dynPE

atm2ocn _couplerAs a consequence, Coupler Components must be defined on the union of the PEs of all the Components that they couple.

In this example, in order to send data from the atmosphere Component to the ocean, the atm2ocn Coupler mediates the send.


Design Principle:Scalable Applications

Since each ESMF application is also a Component, entire ESMF applications can be treated as Gridded Components and nested within larger applications.

climate_comp

ocn_comp atm_comp

ocn2atm_coupler

atm_phys

phys2dyn_coupler

atm_dynPE

Example: atmospheric application itself composed of multiple Components may be run standalone, or nested within a larger climate application


Design Principle: ModularityGridded Components don’t have access to the internals of other Gridded Components, and don’t store

any coupling information. Gridded Components may:• pass their States to other Components through their argument list or• receive user-defined methods through their argument list for transforming and transferring States.

These are called Transforms, and they contain a function pointer and attributes describing frequency and validity criteria. Transforms may modify the data in States, receive States from other Components, send States to other Components, etc.

! From climate compcall ESMF_CompRun(atm, atm_xform)call ESMF_CompRun(ocn, ocn_xform)

! From atm compcall ESMF_StateXform(atm_ex_state, & atm_xform)! From ocn compcall ESMF_StateXform(ocn_im_state, &

ocn_xform)

EX 1: One-way coupling from atm to ocnatm_xform is a send; ocn_xform a receive

EX 2: Standalone atmatm_xform is a no-op

! From atm compcall ESMF_CompRun(ocn, ocn_xform)call ESMF_StateXform(atm_ex_state, &

atm_xform)


Design Principle:Uniform Communication APIThe same programming interface is used for shared memory, distributed memory, and combinations thereof.

Machine model = abstraction of machine architecture (num_nodes, num_pes_per_node, etc.)

DE = a decomposition element - may be virtual, thread, MPI process

DELayout = an arrangement of DEs, in which dimensions requiring faster communication may be specified and resources arranged accordingly

DELayout: 4 x 3, ESMF_COMM_SHR in x and ESMF_COMM_MP in yThe data in a Grid is decomposed according to the number and topology of DEs in the DELayout

Performance of ESMF AllGather vs. raw MPI


Outline



Time Line

May 2002 Draft Developer’s Guide and Requirements Document completed

1st Community Requirements Meeting and review held in D.C.

July 2002 ESMF VAlidation (EVA) suite assembled

August 2002 Architecture Document: major classes and their relationships

Implementation Report: language strategy and programming model

Software Build and Test Plan: sequencing and validation

May 2003 ESMF Version 1.0 release, 2nd Community Meeting at GFDL

November 2003 First 3 interoperability experiments completed

April 2004 Second API and production software release, 3rd Community Meeting

November 2004 All interoperability experiments complete; all testbed applications compliant

January 2005 Final delivery of source code and documentation


More Information

ESMF website: http://www.esmf.ucar.edu

AcknowledgementsThe ESMF is sponsored by the NASA Goddard Earth Science Technology Office.

Documents

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH C. DeLuca/NCAR, J. Anderson/NCAR, V. Balaji/GFDL, B. Boville/NCAR, N. Collins/NCAR,