NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Chris Hill, MIT TOMS, 2003, Boulder Earth System Modeling Framework Overview NSIPP Seasonal Forecast NCAR/LANL CCSM NCEP Forecast GFDL FMS Suite MITgcm NASA GSFC PSAS

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Talk Outline Project Overview Architecture and Current Status – Superstructure layer Design Adoption – Infrastructure layer What is it for What it contains Next steps…. Open Discussion

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Technological Trends 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. Time mean air-sea CO2 flux. MITgcm constrained by obs. + ocean carbon (MIT,Scripps,JPL).

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Community Response Modernization of modeling software Abstraction of underlying hardware to provide uniform programming model, runs efficiently across vector and single and multiple microprocessor architectures. Distributed software development model characterized by many contributing authors; use high- level language features for abstraction, to facilitate development process and software sharing. Modular design for interchangeable dynamical cores and physical parameterizations, development of community-wide standards for components Development of prototype infrastructures GFDL (FMS), NASA/GSFC (GEMS), NCAR/NCEP (WRF), NCAR/DOE (MCT), MIT(Wrapper), ROMS/TOMS etc.. ESMF aims to unify and extend these efforts.

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH ESMF Goals and Products STATED GOAL: To increase software reuse, interoperability, ease of use and performance portability in climate, weather, and data assimilation applications, implies unified “standards”. PRODUCTS: Coupling superstructure and utility infrastructure software Synthetic code suite for validation and demonstration Set of 15 ESMF-compliant applications (including CCSM, WRF, GFDL models; MITgcm, NCEP and NASA data assimilation systems) Set of 8 interoperability experiments Interoperability

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH ESMF Interoperability Demonstrations COUPLED CONFIGURATIONNEW SCIENCE ENABLED GFDL B-grid atm / MITgcm ocnGlobal biogeochemistry (CO2, O2), SI timescales. GFDL MOM4 / NCEP forecastNCEP seasonal forecasting system. NSIPP ocean / LANL CICESea ice model for extension of SI system to centennial time scales. NSIPP atm / DAO analysisAssimilated initial state for SI. DAO analysis / NCEP modelIntercomparison of systems for NASA/NOAA joint center for satellite data assimilation. DAO CAM-fv / NCEP analysisIntercomparison of systems for NASA/NOAA joint center for satellite data assimilation. NCAR CAM Eul / MITgcm ocnImproved climate predictive capability: climate sensitivity to large component interchange, optimized initial conditions. NCEP WRF / GFDL MOM4Development of hurricane prediction capability.

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Talk Outline Project Overview Architecture and Current Status – Component based approach – Superstructure layer Design Adoption – Infrastructure layer What is it for What it contains Next steps…. Open Discussion

ESMF overall structure ESMF uses a component based approach The framework provides an upper “superstructure” layer and a lower “infrastructure” layer User written code (simulation algorithms, DA algorithms …) is sandwiched between the two layers. – User code provides standard interfaces that are called from the superstructure layer – User code uses facilities in the infrastructure for parallelism, I/O, interpolation

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH 2. ESMF provides a toolkit that components use to i.ensure interoperability ii.abstract common services ESMF Programming Model Component: run(), checkpoint() Field: halo(), import(), export() + I/O Grid: regrid(), transpose() + Metrics Layout, PEList, Machine Model Application Component Gridded Components Coupler Components 1. ESMF provides an environment for assembling components. user written 3. Gridded components, coupler components and application components are user written. SUPERSTRUCTURELAYER INFRASTRUCTURELAYER

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Superstructure Layer: Assembles and connects components Since each ESMF application is also a component, entire ESMF applications may be treated as Gridded Components and nested within larger applications. climate_comp ocn_comp atm_comp ocn2atm_coupler atm_phys phys2dyn_coupler atm_dyn PE Example: atmospheric application containing multiple coupled components within a larger climate application

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Superstructure Layer: Controlling subcomponents Components must provide a single externally visible entry point which will register the other entry points with the Framework. Components can: - Register one or more Initialization, Run, Finalize, and Checkpoint entry points. - Register a private data block which can contain all data associated with this instantiation of the Component; particularly useful when running ensembles. Higher level Comp cmp_register() cmp_run() cmp_final() cmp_init() ESMF Framework Services Public subroutine Private subroutine

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Superstructure Layer: Passing data between components I Gridded Components do not have access to the internals of other Gridded Components. They have 2 options for exchanging data with other Components; the first is to receive Import and Export States as arguments. coupler ocn_component subroutine ocn_run(comp, & ImportState,ExportState, Clock, rc) atm_component subroutine atm_run(comp, & ImportState,ExportState, Clock, rc) States contain flags for “is required”, “is valid”, “is ready”, etc.

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Gridded Components using Transforms do not have to return control to a higher level component to send or receive State data from another component. They can receive function pointers which are methods that can be called on the states. coupler ocn_component call ESMF_StateXform(ex_state, & xform) atm_component call ESMF_StateXform(xform, & im_state) transform call ESMF_CompRun(atm, xform) call ESMF_CompRun(ocn, xform) Superstructure Layer: Passing data between components II

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Superstructure Layer: Parallel Communication All inter-component communication within ESMF is local. climate_comp ocn_comp atm_comp atm_phys phys2dyn_coupler atm_dyn PE atm2ocn _coupler This means: 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 ocean component to the atmosphere, the Coupler mediates the send.

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Superstructure Layer: Summary Provides means to connect components together Components can be connected in a hierarchy Provides a general purpose mechanisms for passing data between components Data is self-describing Provides a general purpose mechanism for “parent” components to control “child” components Stepping forward, backward, initializing state etc…

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Infrastructure Layer 1.A standard software platform for enabling interoperability (developing couplers, ensuring performance portability). 2.Set of reusable software for Earth science applications. Streamlined development for researchers. NCAR Atmosphere GFDL Ocean NSIPP Land NCAR Atmosphere GFDL Ocean NSIPP Land My Sea Ice

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Infrastructure Layer Scope Support Support for Physical Grids Regridding Decomposition/composition Communication Calendar and Time I/O Logging and Profiling ESMF Infrastructure User Code ESMF Superstructure

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Field and Grid : grid = ESMF_GridCreate(…,layout,…) : field_u = ESMF_FieldCreate(grid, array) : 1.Create field distributed over a set of decomposition elements (DE’s). 2.Domain decomposition determined by DELayout, layout. 3.Each object ( grid and field_u ) has internal representation. 4.Other parts of the infrastructure layer use the internal representation e.g. Regrid() – interpolation/extrapolation + redistribute over DE’s Redistribution() - general data rearrangement over DE’s Halo() – specialized redistribution ESMF_Array info. ESMF_Field metadata ESMF_Grid

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Regrid Function mapping field’s array to a different physical and distributed grid. RegridCreate() – creates a Regrid structure to be used/re-used regrid = ESMF_RegridCreate(src_field, dst_field, method, [name], [rc]) Source, Dest field can be empty of field data (RegridCreate() uses grid metrics) – PhysGrid, DistGrid info used for setting up regrid – Resulting regrid can be used for other fields sharing same Grid Method specifies interpolation algorithm. For example, bilinear, b-spline, etc…

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Regrid Interface (cont) RegridRun() – performs actual regridding call ESMF_RegridRun(src_field, dst_field, regrid,[rc]) – Communication and interpolation handled transparently. RegridDestroy() – frees up memory call ESMF_RegridDestroy(regrid,[rc]) src_field dst_field

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Redistribution No interpolation or extrapolation Maps between distributed grids, field’s array and physical grid are the same i.e. Example: layout() created two distributed grids one decomposed in X and one decomposed in Y. – Redistribution() function maps array data between the distributions (a transpose/corner turn) – Communication handled transparently src_field dst_field

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Halo Fields have distributed index spaces of – Exclusive {E}, compute {C} and local {L} region where Halo() fills points not in {E} or {C} from remote {E} e.g {E} {C} {L} {C} {L} {E} call ESMF_FieldHalo(field_foo, status) DE3 DE4

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH More functions in reference manual e.g

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Bundle and Location Stream ESMF_Bundle – collection of fields on the same grid ESMF_LocationStream – Like a field but….. – unstructured index space with an associated physical grid space – useful for observations e.g. radiosonde, floats Functions for create(), regrid(), redistribute(), halo() etc…

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH ESMF Infrastructure Utilities Clock Alarm Calendar I/O Logging Profiling Attribute Machine model and comms Ensures consistent time between components Provides field level I/O in standard forms – netCDF, binary, HDF, GRIB, Bufr Consistent monitoring and messaging Consistent parameter handling Hardware and system software hiding. Platform customizable

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Time Standard type for any component Calendar (support for range of calendars) ! initialize stop time to 13May2003, 2:00 pm call ESMF_TimeInit(inject_stop_time, & YR=int(2003,kind=ESMF_IKIND_I8), & MM=off_month, DD=off_day, H=off_hour, M=off_min, & S=int(0,kind=ESMF_IKIND_I8), & cal=gregorianCalendar, rc=rc) do while (currTime.le. inject_stop_time ) : call ESMF_ClockAdvance(localclock, rc=rc) call ESMF_ClockGetCurrTime(localclock, currtime, rc) end call ESMF_CalendarInit(gregorianCalendar, ESMF_CAL_GREGORIAN, rc)

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Time Representations type(ESMF_Calendar) :: calendar1 call ESMF_CalendarInit(calendar1, ESMF_CAL_GREGORIAN, rc) - ESMF_CAL_GREGORIAN (3/1/-4800 to 10/29/292,277,019,914) - ESMF_CAL_JULIAN (+/- 106,751,991,167,300 days) - ESMF_CAL_NOLEAP - ESMF_CAL_360DAY - ESMF_CAL_USER

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH I/O Field level binary, netCDF, HDF, GRIB, bufr, extensible… – Currently I/O piped through 1 PE call ESMF_FieldAllGather(field_u, outarray, status) if (de_id.eq. 0) then write(filename, 20) "U_velocity", file_no call ESMF_ArrayWrite(outarray, filename=filename, rc=status) endif call ESMF_ArrayDestroy(outarray, status)

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Internal Classes Machine model – Captures system attributes, CPU, mem, connectivity graph – Useful for defining decomposition, load-balance, performance predictions. Comms – Communication driver, allows bindings to MPI, shared memory, vendor system libraries

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Comms Performance Test Right mix (green) on Compaq gives x2 realized bandwidth (in large message limit)

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Talk Outline Project Overview Architecture and Current Status – Superstructure layer Design Adoption – Infrastructure layer What is it for What it contains Next steps…. Open Discussion

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Timeline May 2002Draft Developer’s Guide and Requirements Document completed Community Requirements Meeting and review held in D.C. July 2002ESMF VAlidation (EVA) suite assembled August 2002Architecture Document: major classes and their relationships Implementation Report: language strategy and programming model Software Build and Test Plan: sequencing and validation May First API and software release, Community Meeting at GFDL July 2003First 3 interoperability experiments completed April 2004Second API and software release, Community Meeting July 2004All interoperability experiments completed

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH May 2003 Release Focus for May 2003 ESMF release was on developing sufficient infrastructure and superstructure to achieve the initial set of interoperability experiments. These are: – FMS B-grid atmosphere coupled to MITgcm ocean – CAM atmosphere coupled to NCEP analysis – NSIPP atmosphere coupled to DAO analysis

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Regrid Next Steps Support for all ESMF Grids Support for regridding methods including: Bilinear Bicubic 1 st -order Conservative 2 nd -order Conservative Rasterized Conservative Nearest-neighbor distance-weighted average Spectral transforms 1-d interpolations (splines) Index-space (shifts, stencils) Adjoints of many above

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Distributed Grid Regular 2d already supported Next steps – Generalized 1d decomposition – Extend support for 2d and quasi regular decomposition – Spectral grid decompositions – Composite grids Larger set of metrics, grids High level routines for rapid definition of common grids. Physical Grid Next Steps

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH I/O Next Steps Broaden format set, binary, netCDF, HDF, GRIB, bufr Improve parallelization Full support for alarms Broader functionality Time/Logging/Profiling Next Steps

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Summary ESMF Current Status – Comprehensive class structure available in version 1.0 – Over the coming year significant extension of functionality will take place. – Feedback and comments on version 1.0 welcome

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Talk Outline Project Overview Architecture and Current Status – Superstructure layer Design Adoption – Infrastructure layer What is it for What it contains Next steps…. Open Discussion

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

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Questions from Hernan, cont..

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Questions from Hernan, cont..

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Questions from Hernan, cont..

Last but not least - an interesting potential benefit of “component” based approaches Component based approaches could provide a foundation for driving high-end applications from “desktop” productivity environments. For example driving a parallel ensemble GCM run from Matlab becomes conceivable! To learn more visit us at MIT!!!

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

ESMF Infrastructure Utility detailed example Earl Schwab, ESMF Core Team, NCAR Time Manager

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH What is Time Manager? Clock for time simulation Time representation Time calculator Time comparisons Time queries F90 API, C++ implementation

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Clock for time simulation type(ESMF_Clock) :: clock call ESMF_ClockInit(clock, timeStep, startTime, stopTime, rc=rc) do while (.not.ESMF_ClockIsStopTime(clock, rc)) ! Do application work. call ESMF_ClockAdvance(clock, rc=rc) end do

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Clock (cont.) Clock queries/commands call ESMF_ClockGetCurrTime(clock, currTime, rc) call ESMF_ClockSetCurrTime(clock, currTime, rc) call ESMF_ClockGetTimeStep(clock, timeStep, rc) call ESMF_ClockSetTimeStep(clock, timeStep, rc) call ESMF_ClockGetAdvanceCount(clock, advanceCount, rc) call ESMF_ClockGetStartTime(clock, startTime, rc) call ESMF_ClockGetStopTime(clock, stopTime, rc) call ESMF_ClockGetPrevTime(clock, prevTime, rc) call ESMF_ClockSyncToWallClock(clock, rc)

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Common Component Architecture CCSM Coupled System, NASA GEMS, GFDL FMS, MITgcm, etc… Single Earth system model or modeling system Earth System Modeling Framework Climate, Weather, Data Assimilation All HPC Applications ESMF within the broader computational hierarchy

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Time Representation type(ESMF_Calendar) :: calendar1 call ESMF_CalendarInit(calendar1, ESMF_CAL_GREGORIAN, rc) - ESMF_CAL_GREGORIAN (3/1/-4800 to 10/29/292,277,019,914) - ESMF_CAL_JULIAN (+/- 106,751,991,167,300 days) - ESMF_CAL_NOLEAP - ESMF_CAL_360DAY - ESMF_CAL_USER

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Attributes Flexible parameter specs, configuration e.g. file of parameters Code

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Technological Trends 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. Time mean air-sea CO2 flux. MITgcm constrained by obs. + ocean carbon (MIT,Scripps,JPL).

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Time Representation (cont.) type(ESMF_Time) :: time1 call ESMF_TimeInit(time1, YR=int( 2003,kind=ESMF_IKIND_I8), & MM= 5, DD= 15, H= 15, cal=calendar1, rc=rc) - YR, MM, DD, H, M, S F90 optional - D, H, M, S arguments type(ESMF_TimeInterval) :: timeInterval1 call ESMF_TimeIntervalInit(timeInterval1, D=int( 90,kind=ESMF_IKIND_I8), rc=rc) - D, H, M, S F90 optional arguments

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Time Calculator Time differencing Time increment/decrement by a time interval Time interval arithmetic (+, -, *, /)

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Time Calculator (cont.) call ESMF_TimeInit(time1, YR=int( 2003,kind=ESMF_IKIND_I8), & MM= 5, DD= 15, cal=gregorianCalendar, rc=rc) call ESMF_TimeInit(time2, YR=int( 2003,kind=ESMF_IKIND_I8), & MM= 3, DD= 26, cal=gregorianCalendar, rc=rc) call ESMF_TimeIntervalInit(timeInterval1, D=int( 90,kind=ESMF_IKIND_I8, rc=rc) timeInterval2 = time2 - time1 time1 = time1 + timeInterval1 ! Uses F90 overloaded timeInterval3 = timeInterval1 * 2 ! operators double precision :: ratio ratio = timeInterval1 / timeInterval2

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Time Comparisons >, =, F90 overloaded operators between any 2 times or time intervals if (time1 < time2) then … end if if (timeInterval1.ge. timeInterval2) then … end if

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Time Queries call ESMF_TimeGet(time1, YR=yr, MM=mm, DD=dd, H=h, M=m, S=s, rc=rc) call ESMF_TimeIntervalGet(timeInterval1, D=d, H=h, M=m, S=s) call ESMF_TimeGetDayOfYear(time1, dayOfYear, rc)! double or integer call ESMF_TimeGetDayOfMonth(time1, dayOfMonth, rc) call ESMF_TimeGetDayOfWeek(time1, dayOfWeek, rc) call ESMF_TimeGetMidMonth(time1, midMonth, rc) call ESMF_TimeGetString(time1, string, rc) ! T12:20:19 (ISO 8601) call ESMF_TimeIntervalGetString(timeInterval1, string, rc) ! P1DT12H0M0S (ISO) call ESMF_TimeGetRealTime(time1, rc)

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH More information ESMF User’s Guide ESMF Reference Manual ESMF Requirements Document Time Manager F90 API & examples source code esmf_1_0_0_r/src/Infrastructure/TimeMgr/interface esmf_1_0_0_r/src/Infrastructure/TimeMgr/examples

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH 2. ESMF provides a toolkit that components use to i.ensure interoperability ii.abstract common services Location Within ESMF Component: run(), checkpoint() Field: halo(), import(), export() + I/O Grid: regrid(), transpose() + Metrics Layout, PEList, Machine Model Application Component Gridded Components Coupler Components 1. ESMF provides an environment for assembling components. INFRASTRUCTURELAYER

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH ESMF Infrastructure Fields and Grids Field Contains array, grid, array to grid mapping and metadata Array Holds actual data e.g. temperature, wind speed etc… Grid Contains physical and distributed grid Physical Grid Grid metrics, e.g. lat-lon coords, spacings, areas, volumes etc.. Distributed Grid Parallel decomposition information

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Creating an ESMF Field 1.Fortran Array 2.Array Attach 3.Field Attach Array real, dimension(100,100) :: arr esArr = ESMF_ArrayCreate(arr,…) ESMF_Array info. ESMF_Array info. ESMF_FieldAttachArray(esFld,esArr,…) ESMF_Field metadata ESMF_Grid

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Creating an ESMF Grid ESMF_Grid PhysGrid DistGrid call ESMF_PhysGridCreate…(…) call ESMF_DistGridCreate…(…)

NSF NCAR / NASA GSFC / DOE LANL ANL / NOAA NCEP GFDL / MIT / U MICH Infrastructure Internal Organization MachineModel DELayout DistGrid PhysGrid Bundle Array Time, Alarm, Calendar, LogErr, I/O, Attributes F90 C++ Field Grid Regrid Comm Data Communications Route Two tiers Class hierarchy for data and communications