ESMF-based applications with the
National Unified Operational
Prediction Capability
Tim Campbell
Naval Research Laboratory
Outline
Describe how NUOPC Layer is implemented in Navy
ESM systems (focus on regional ESM). Hopefully,
illuminate how NUOPC improves interoperability.
Describe some areas that still need work.
• Overview of COAMPS
• Specialization of NUOPC Generic Components
• Initialization Sequencing
• Field Brokering
• Further Developments in NUOPC
2/20/13
2
Coupled Ocean-Atmosphere Mesoscale
Prediction System
Regional coupled atmosphere/ocean/wave prediction system with data-assimilation.
2/20/13
3
Current Design with ESMF
COAMPS_Driver
ESMF_GridComp
(Initialize, Run,
Finalize)
OCN
ATM
(internal surface layer)
Model
connections
controlled by
COAMPS_Driver
WAV
• No brokering of inter-model connections (set by input list of coupling fields)
• COAMPS specific field names hardwired into models
• Difficult to add new models and new coupling fields
2/20/13
4
Current Design with NUOPC-ESMF
COAMPS_Driver (derived from NUOPC_Driver)
NUOPC_Model
(Multiphase
Intialize, Run,
Finalize)
OCN
ATM
(internal surface layer)
NUOPC_Connector
(connect import
state to export
state, compute &
execute regrid
routeHandle(s))
WAV
• Brokering of inter-model connections (NUOPC_Connector)
• Coupling determined by model import fields (model specified BCs)
• Field names obtained from NUOPC_FieldDictionary
2/20/13
5
Future Design with NUOPC-ESMF
COAMPS_Driver (derived from NUOPC_Driver)
NUOPC_Model
(Multiphase
Intialize, Run,
Finalize)
NUOPC_Mediator
(flux calculations)
ICE
ATM
MED
OCN
NUOPC_Connector
(connect import
state to export
state, compute &
execute regrid
routeHandle(s))
WAV
• Brokering of inter-model connections (NUOPC_Connector)
• Coupling determined by model import fields (model specified BCs)
• Field names obtained from NUOPC_FieldDictionary
2/20/13
6
Specialization from NUOPC_Driver
use NUOPC_Driver, only: &
routine_SetServices, &
type_InternalState, &
label_InternalState, &
label_SetModelCount, &
label_SetModelPetLists, &
label_SetModelServices
Required Methods:
SetServices – set entry points for driver methods
Specializing Methods:
SetModelCount – set number of models controlled by driver
SetModelPetLists – set processor layout for each model
SetModelServices – call into SetServices for each model,
define run sequence
The run sequence encodes the order in which models and connectors are
executed. Knowledge of inter-model data-dependencies is required.
2/20/13
7
Specialization from NUOPC_Model
use NUOPC_Model, only: &
routine_SetServices, &
type_InternalState, &
label_InternalState, &
label_DataInitialize, &
label_SetClock, &
label_Advance
Required Methods:
SetServices – set entry points for model methods
InitializeP0 – set version of NUOPC initialization sequence
InitializeP1 – advertise import & exportable fields
InitializeP2 – realize import fields & connected export fields
Specializing Methods:
SetClock – set internal clock
DataInitialize – initialize export fields
ModelAdvance – advance model in time
2/20/13
8
Specialization from NUOPC_Connector
use NUOPC_Connector, only: &
routine_SetServices, &
type_InternalState, &
label_InternalState, &
label_ComputeRouteHandle, &
label_ExecuteRouteHandle, &
label_ReleaseRouteHandle
Required Methods:
SetServices – set entry points for connector methods
Specializing Methods:
ComputeRH – create & store export-to-import data routing
ExecuteRH – execute export-to-import data routing
ReleaseRH – destroy export-to-import data routing
2/20/13
9
ESMF to ESMF-NUOPC
• Refactor code in each model’s ESMF layer
– change single initialize phase into multiple phases and
specializing attachable methods
– change run phase to ModelAdvance method
– acceptable amount of code change
– resulting code is improved in that each method has a welldefined purpose that is understood by the driver
• Implement new driver specialized from NUOPC_Driver
– new driver is more streamlined and flexible
– same driver will be used in several Navy ESM systems
• Main challenge was in understanding the NUOPC API
2/20/13
10
Initialize Sequence – Satisfying Intermodel Data Dependencies
ATM
SST
OCN
2/20/13
WIND
SSH, SSC
WAV
• OCN does not require import fields to compute initial state
• ATM requires SST to compute initial state
• WAV requires WIND, SSH and SSC to compute initial state
11
Initialize Sequence – Satisfying Intermodel Data Dependencies
• Each model “knows” what is required in order to compute
its initial state and export fields (e.g., WAV requires wind
and currents)
• In DataInitialize method each model:
– checks time-stamp on import fields required to compute export
fields
– sets “Updated” attribute on updated export fields
• Connector ExecuteRH method time-stamps import fields
that are mapped from “Updated” export fields
• Driver cycles Connector ExecuteRH and model DataInitialize
methods until all models declare that initialize datadependencies are satisfied or until a dead-lock is detected.
2/20/13
12
Initialize Sequence – Satisfying Intermodel Data Dependencies
2
ATM
SST 2
1
WIND
2
OCN
2/20/13
3
SSH, SSC
WAV
3
• Three steps of ExecuteRH & DataInitialize required
• Each model only encodes its own required data dependencies
• Driver executes generic sequence and detects dead-lock (no progress)
13
Field Brokering
• Pre-NUOPC enabled COAMPS:
– Fields do not have attributes
– Inter-model connections imposed by driver using field
name
– COAMPS specific field names encoded into each model
• NUOPC enabled COAMPS:
–
–
–
–
2/20/13
Fields have attributes (StandardName, Units, etc)
Inter-model connections based on StandardNames
NUOPC Field StandardNames encoded into each model
Models can query NUOPC FieldDictionary to obtain
CanonicalUnits and default ShortName
14
Further Developments in NUOPC
• Field Brokering
– Establish a method for constructing
StandardNames that uniquely identify fields
– CF, CSDMS?
• Establish method by with the run sequence
can be determined from Model attributes.
– similar to the initialize phase definition
2/20/13
15
Thank-You
Questions?