Emergence of a Common Modeling Architecture for Earth System Science

American Geophysical UnionDecember 13, 2010

Cecelia DeLucaNOAA/CIRES

Outline

• Motivation• Evolution• Component Interfaces• Common Model Architecture• National Unified Operational Prediction Capability• Creating and Using a Structured Information Layer• Summary

Motivation

• Climate and other Earth system models include significant non-scientific and utility infrastructure

• Shared standards-based infrastructure development enables:– Ability of multiple groups to contribute to coupled systems– Reuse of software to promote efficient use of resources– A technical culture that can emphasize best practices and can be

less isolating than the “scientist’s programmer” – Software with features, testing, and documentation that exceeds

in scope and quality what a single institution can produce

time

softwareinfrastructurecapability

2000 2010

best available institutional/proprietary capability

best available community capability

Community Modeling Infrastructure Projects

• 2002 - Earth System Modeling Framework – climate and weather model coupling (http:///www.earthsystemmodeling.org)

• 2000 - OASIS Coupler/Programme for Integrated Earth System Modeling (PRISM) – climate model coupling (http://www.cerfacs.fr)

• 2000 - Earth System Grid – distribution of climate model output (http://wwwearthsystemgrid.org)

• 1995 - Climate and Forecast Conventions – metadata conventions for data (http://cf-pcmdi.llnl.gov/)

• 2005 - METAFOR Common Information Model for climate models – metadata conventions for climate model metadata (http://metaforclimate.eu)

• 2005 - Earth System Curator – climate model workflows (http://earthsystemcurator.org)

Note: 1) not exhaustive and 2) major advances since 2000!

Evolution of ESMF

Phase 1: 2002-2005•NASA’s Earth Science Technology Office ran a solicitation to develop an Earth System Modeling Framework (ESMF).•A multi-agency collaboration won the award. The team included developers of major institutional tools and frameworks (from GFDL, Goddard, NCAR, Los Alamos, MIT, …)•The core development team was located at NCAR.•A prototype ESMF software package (version 2r) demonstrated feasibility.

Phase 2: 2005-2010•New sponsors included Department of Defense and NOAA.•Many new applications and requirements were brought into the project, motivating a complete redesign of framework data structures (version 3r).

Phase 3: 2010-2015•The core development team moved to NOAA for closer alignment with federal models.•Basic framework development will be complete with version 5r (ports, bugs, feature requests, user support etc. still require resources).•The focus is on increasing adoption and creating a community of interoperable codes.

Standard Component Interfaces

• All ESMF components have the same three standard methods:– Initialize– Run– Finalize

• Each standard method has the same simple interface:

• These interfaces are wrappers, and can often be set up in a non-intrusive way

call ESMF_GridCompRun (myComp, importState, exportState, clock, …)

Where:myComp points to the componentimportState is a structure containing input fieldsexportState is a structure containing output fieldsclock contains timestepping information

Steps to adopting ESMF• Divide the application into components

(without ESMF)• Copy or reference component input and

output data into ESMF data structures• Register components with ESMF• Set up ESMF couplers for data exchange

A Common Model Architecture

• Increasingly, models in the U.S. follow a common architecture

• Atmosphere, ocean, sea ice, land, and/or wave models are components called by a top-level driver/coupler

• Components use ESMF or ESMF-like interfaces (see left)

• Many major U.S. weather and climate models either follow this architecture (CCSM/CESM, COAMPS, NEMS), want to follow this architecture for future coupled systems (NOGAPS), or have a different style of driver but could provide components to this architecture (GEOS-5, FMS)

Even non-ESMF codes now look like ESMF …

ESMF:ESMF_GridCompRun(gridcomp, importState,exportState, clock, phase, blockingFlag, rc)

CESM (non-ESMF version):atm_run_mct(clock, gridcomp, importState,exportState)(argument names changed to show equivalence)

WRF

HYCOM

CICE IcePOP Ocean

CCSM4/CESM

NMM-B Atm PhysNMM-B Atm DynamicsNEMS

NMM History

GFS Atm Phys GFS Atm DynamicsGFS

GFS I/O

FV Cub Sph DycoreGEOS-5 GWD GEOS-5 FV Dycore

GEOS-5 Atm Dynamics

GEOS-5

GSI

GEOS-5 Moist Proc

GEOS-5 Turbulence

GEOS-5 LW Rad GEOS-5 Solar Rad

GEOS-5 Radiation

GEOS-5 Aeros Chem

GOCART

Strat ChemParam Chem

GEOS-5 Atm Chem

GEOS-5 Ocean BiogeoGEOS-5 Salt WaterPoseidon GEOS-5 Data Ocean

GEOS-5 OGCM

GEOS-5 Topology

GEOS-5 Land Ice

GEOS-5 Lake GEOS-5 Veg Dyn GEOS-5 Catchment

GEOS-5 Land

GEOS-5 Surface

GEOS-5 Atm PhysicsGEOS-5 Hiistory

ESMF Model Components 2010

NOAADepartment of DefenseUniversityNASADepartment of EnergyNational Science Foundation

ESMF coupling complete

Component (thin lines)Model (thick lines)

LegendOvals show ESMF components and modelsthat are at the working prototype level orbeyond.

Tracer Advection

CLM Land CAM Atm FIM

Land Info System

HAF

GAIM

MOM4

SWAN

ADCIRCpWASH123

COAMPSWWIII

NCOM

NOGAPS

A Common Model Architecture

• The U.S. Earth system modeling community is converging on a common modeling architecture

• Atmosphere, ocean, sea ice, land, wave, and other models are ESMF or ESMF-like components called by a top-level driver or coupler

• Some models are modularizing further with nested components

A Common Model Architecture

Common Model Architecture inClimate Metadata

CMIP5 metadata display in Earth System Grid, developed by theEarth System Curator project in collaboration with E.U. METAFOR

From Common Model Architecture to Interoperability

• ESMF component interfaces alone do not guarantee technical interoperability – ESMF can be implemented in multiple ways

• Also need:– A common physical architecture – the scope and

relationships of physical components (e.g. land surface as subroutine or component?)

– Metadata conventions and usage conventions (e.g. who can modify component data?)

– The next steps for modeling infrastructure involve encoding these conventions in software tools and templates

National Unified Operational Prediction Capability

• National Unified Operational Prediction Capability (NUOPC) is a consortium of operation weather prediction centers

• Developing a standard implementation of ESMF across NASA, NOAA, Navy, Air Force and other modeling applications

• Defining a target level of interoperability involving multiple aspects of code – EXAMPLES:Component interface. Components have a standard calling interface to facilitate generic drivers and communication protocols. Standardization does not include specification of what specific fields are actually in the import and export state.Timekeeping. Metadata and conventions for timekeeping enable modelers to understand without code inspection whether components can be coupled together.From: Final Report from the National Unified Operational Prediction Capability (NUOPC) Interim Committee on Common Model Architecture (CMA), June 18, 2009.

Applications of information

layer

Building an Information andInteroperability Layer

Native model data structures

Standard data structures

Standard metadata

• Parallel generation and application of interpolation weights• Run-time compliance checking of metadata and time behavior• Fast parallel I/O• Redistribution and other parallel communications• Automated documentation of models and simulations (new)• Ability to run components in workflows and as web services (new)

Field Grid ClockComponent

Attributes: CF conventions, ISO standards, METAFOR Common Information Model

Structured model information stored in ESMF wrappers

User data is referenced or copied into ESMF structures

modulesfields

gridstimekeeping

ESMF data structures

Summary• U.S. models are converging on a common model architecture• It is built on standardized component interfaces wrapped

around user code• This architecture creates a layer of structured information in

Earth system codes• This structured information can be accessed for many functions

– To support interoperability, through efforts like NUOPC– As a building block for self-documentation of models,

automated compliance checking, and other advanced capabilities

– To learn more … the ESMF town hall meeting is Wednesday from 12:30-1:30 in Moscone West Room 2007