Increasing the usablity of NCEP forecast models using

Increasing the usablity of NCEP forecast models using (prototype) National Environmental Modeling System (NEMS) Mark Iredell Global Interoperability Program Kickoff Meeting November 6, 2009 1

NOAA Environmental Modeling System (NEMS) (uses standard ESMF compliant software) Application Driver ESMF Superstructure (component definitions, “mpi” communications, etc) Atmospheric Model Dynamics (1, 2, 3) 1 -1 1 -2 1 -3 2 -1 2 -2 2 -3 Physics (1, 2, 3) Chemistry (Gc, Cm) Multi-component ensemble + Stochastic forcing ESMF Utilities (clock, error handling, etc) Coupler 1 Coupler 2 Coupler 3 Coupler 4 Coupler 5 Coupler 6 Etc. Analysis -------Ocean ------Wind Waves -------LSM --------IC/ens gen. -------Ecosystem -------Nests -------Cryosphere -------Magnetosphere -------Etc. Bias Corrector Post processor & Product Generator Verification Resolution change * Earth System Modeling Framework (NCAR/CISL, NASA/GMAO, Navy (NRL), NCEP/EMC), NOAA/GFDL 2, 3 etc: NCEP supported thru NUOPC, NASA, NCAR or NOAA institutional commitments 2 Components are: Dynamics (spectral, FV, NMM, FIM, ARW, FISL, COAMPS…) Physics (GFS, NRL, NCAR, GMAO, ESRL, GFDL…)

NEMS Atmosphere Color Key Component class Atmosphere Coupler class unified atmosphere including digital filter Completed Instance Under Development Future Development Dynamics ARW NMM-B FVCS Spectral NOGAPS FIM COAMPS FISL Dyn-Phy Coupler Simple Regrid, Redist, Chgvar, Avg, etc Physics NAM Phy GFDL Phy GFS Phy WRF Phy Navy Phy • The goal is one unified atmospheric component that can invoke multiple dynamics and physics. • At this time, dynamics and physics run on the same grid in the same decomposition, so the coupler literally is very simple. 3

Write history and Post processor Color Key Component class Coupler class Atmosphere Completed Instance unified atmosphere Under Development Future Development Dynamics Physics Write NEMSIO Post GRIB 1 GRIB 2 net. CDF 4 • The Write component can transfer state from model tasks to “quilt” tasks and then writes out from there. • NEMSIO is a unified optimized parallelized I/O package that can write several formats. 4 • The unified post-processor NCEP_POST runs on the quilt tasks.

Run-time Registry • Each component lists fields and their disposition (History, Restart, Import, Export, Ownership) in a run-time registry. NMMB-Dynamics Temperature GFS-Phys Temperature Precipitation H R I E O H H - I - E - O - • Names linked to internal state names in code, and can be aliased to CF names. • Ownership can be shared during development and single during operations. 5

Ocean, waves and sea ice (possible scenario) Color Key Component class Earth system model Coupler class Atm-Sfc Coupler (Slow) Atmosphere Dynamics Completed Instance Surface (Slow) Under Development Future Development Physics Etc. Rad. Waves Surface (Fast) Ice Turbul ence Ocean Waves Ice Ocean Land • Due to some rapidly interacting physics, some coupling would have to be frequent and possibly iterative. The fast mode components may need to run serially on the atmospheric component’s processors. • The fast and slow “modes” of model components may have different import and output requirements, 6 and notably different layouts, but may share internal states.

NEMS implementation of NAM in 2010 (~5 th quarter) Full NAM domain 4 km CONUS Nest 4 -6 km Alaska Nest 7

Nested atmosphere Color Key Component class Atmosphere driver Coupler class Completed Instance Atmosphere NEMSNMMB Atm nest Coupler Atmosphere nest Under Development Future Development • The atmosphere nest coupler provides boundary conditions for the nests. • Two-way coupling and moving nests are under development. 8

Ensemble atmosphere Color Key Component class Atmosphere driver Coupler class Completed Instance Atmosphere Atm ens Coupler Atmosphere NEMS-GFS Under Development Future Development NEMS-FIM • The atmosphere ensemble coupler provides stochastic forcing for the ensemble. 9

segueing to FIM… 10