Post on 31-Dec-2015
description
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The NOAA Environmental Modeling System at NCEP
Mark Iredell and Tom Black
January 27, 2011
AMS Conference on NWP
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What is NEMS?
• NEMS stands forNOAA Environmental Modeling System
• A shared, portable, high performance software superstructure and infrastructure
• For use in operational prediction models at National Centers for Environmental Prediction (NCEP)
• National Unified Operational Prediction Capability (NUOPC) with Navy and Air Force
• Eventual support to community through Developmental Test Center (DTC)
• http://www.emc.ncep.noaa.gov/NEMS/
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NEMS motivation
– Develop a common superstructure for all NCEP models.
– Modularize large pieces of the models with ESMF components and interfaces.
– Divide atmospheric models down into Dynamics and Physics components but no further.
– Take history file I/O outside the science parts and into a common Write component.
– Keep science code and parallelization code in the respective models the same as before.
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NEMS core developers
Ed Colon makefiles, scripts, regression
Nicole McKee documentation, web, testing
Ratko Vasic upgrades, regression, atmos coupling
Jun Wang IO, post, configuration
Weiyu Yang ensemble, earth coupling, ESMF
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NEMS project developersTom Black
Dusan Jovic
Jim Abeles
NAM
S Moorthi
Henry Juang
GFS
Jesse Meng
Jim Geiger
Land
Sarah Lu
Arlindo da Silva
GOCART
Tom Henderson
Jim Rosinski
FIM
Eugene Mirvis DTC
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NEMS Component Structure
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MAIN
EARTH(1:NM)
Ocean Atm Ice
NMM GFS FIM
Dyn Phy
Domains(1:ND)
Below the dashed line the source codes are organized by the model developers.
Wrt Dyn Phy Wrt Dyn Phy Wrt
NEMS
Ensemble Coupler
Chem
All boxes represent ESMF components.
NEMSLAYER
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NEMS implementation plans
• 2011 implementation– NMMB with nests
• 2012 implementation– NEMS GFS Aerosol Component (NGAC)
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12 km NAM will still 12 km NAM will still run to 84 hr, with run to 84 hr, with current outputcurrent output
Fixed domain nests Fixed domain nests run to 60 hrrun to 60 hr– 4 km CONUS 4 km CONUS – 6 km Alaska6 km Alaska– 3 km HI & PR3 km HI & PR
• Single locatable 1.33 Single locatable 1.33 km (CONUS) or 1.5 km km (CONUS) or 1.5 km (Alaska) nest to 36hr(Alaska) nest to 36hr
• NestsNests• Static, 1-way Static, 1-way • Boundaries from Boundaries from
parent every parent every timesteptimestep
• Nest is “grid-Nest is “grid-associated” with associated” with parent (same parent (same orientation w.r.t. orientation w.r.t. earth)earth)
• Moving nests and 2-Moving nests and 2-way interaction way interaction under developmentunder development
NMMB with nestsNMMB with nests
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Atmosphere
Dynamics PhysicsDyn-PhyCoupler
NMM-B
Spectral
Color Key
Generic Component
Generic Coupler
Completed Instance
NAM Phy
GFS Phy
unified atmosphereIncluding digital filter
GOCART
• Dynamics, physics and chemistry run on the same grid in the same decomposition
• GOCART does not own aerosol tracers (i.e, do not allocate aerosol tracer fields)
• PHY2CHEM coupler component transfers/converts data from physics export state to GOCART import state– Convert units (e.g., precip rate, surface roughness)– Calculations (e.g., soil wetness, tropopause pressure, relative humidity,
air density, geopotential height)– Flip the vertical index for 3D fields from bottom-up to top-down
• CHEM2PHY coupler component transfers data from GOCART export state to physics export state– Flip vertical index back to bottom-up– Update 2d aerosol diagnostic fields
Phy-ChemCoupler
NEMS GFS Aerosol NEMS GFS Aerosol Component (NGAC)Component (NGAC)
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NEMS delivery plans
• 2011 deliveries– GFS– GEFS– Postprocessor– FIM– Multimodel ensemble– GRIB2 output
• 2012+ deliveries– NMM nested in GFS – Moving nests– Coupled ocean atmosphere– Tiled land model– netCDF output– ARW
Thank you.
Questions?
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