NEMS/GFS Overview Mark Iredell, Software Team Lead.
-
Upload
bryce-northrop -
Category
Documents
-
view
220 -
download
0
Transcript of NEMS/GFS Overview Mark Iredell, Software Team Lead.
![Page 1: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/1.jpg)
NEMS/GFS Overview
Mark Iredell, Software Team Lead
![Page 2: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/2.jpg)
NEMS/GFS Overview topics.
GFS nomenclatureGFS historyGFS resolutionGFS in NCEP productionGFS & GDAS workflowGSM time splitNEMS motivationNEMS structure
NEMS/GFS Modeling Summer School 2
![Page 3: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/3.jpg)
GFS nomenclature (obsolete)
MRFMedium Range ForecastOnce per day late 10-day global forecastObsolete when merged into GFS
AVNAviation forecastTwice per day early 72-hour global forecastObsolete when merged into GFS
NEMS/GFS Modeling Summer School 3
![Page 4: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/4.jpg)
GFS nomenclature (GFS)
GFSGlobal Forecast SystemApplies to entire suite of jobs from
observation processing to data assimilation to forecast model to product generation, including ensemble (GEFS) and aerosol (NGAC) components, but not seasonal component.
GFS runs four times per day, with “early” (GFS) and a “late” (GDAS) analysis cycles.
NEMS/GFS Modeling Summer School 4
![Page 5: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/5.jpg)
GFS nomenclature (GDAS)
GDASGlobal Data Assimilation SystemApplies to portion of GFS which waits to
run well after real-time, assimilates all available observations, cycles upon itself with 9-hour forecasts, has no customer products, but is the backbone for nearly all NCEP numerical prediction guidance.
NEMS/GFS Modeling Summer School 5
![Page 6: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/6.jpg)
GFS nomenclature (apps)
GSMGlobal Spectral Model “Only” the numerical atmospheric prediction
forecast model applicationUPP
Unified Post Processor (aka NCEP post)Downstream application creating the master
file from which all GFS products are madeGSM & UPP combined in NEMS/GFS
NEMS/GFS Modeling Summer School 6
![Page 7: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/7.jpg)
GFS nomenclature (NEMS)
NEMSNOAA Environmental Modeling SystemApplies to the software framework
containing NCEP’s numerical modelsContains both GSM and UPP componentsAlso contains NGAC and GEFSAlso contains NMM-B and FIM Soon will contain HYCOM and MOM5Uses ESMF and NUOPC to help couple
NEMS/GFS Modeling Summer School 7
![Page 8: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/8.jpg)
GFS history (timeline)
NEMS/GFS Modeling Summer School 8
Find full history timeline at http://www.emc.ncep.noaa.gov/gmb/STATS/html/model_changes.html
![Page 9: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/9.jpg)
GFS resolution (horizontal)
What the heck does “T574” mean?T is triangular, the domain shape in spectral
space. Triangular is isotropic on a sphere.574 is the maximum number of waves
around a great circle in any direction, so the shortest wavelength is 40000/574=70 km.
The Eulerian GSM uses 3 gridpoints per wave, so T574 is on a 1760 x 880 reduced Gaussian grid, or about 23 km.
NEMS/GFS Modeling Summer School 9
![Page 10: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/10.jpg)
GFS resolution (vertical)
NEMS/GFS Modeling Summer School 10
Hybrid sigma-pressure vertical coordinate
Pressure on interface k equalsAk + Bk ps
(linear function of surface pressure)At bottom, A=0, B=1 (sigma)At top, A=0, B=0 (pressure)Pure pressure above 70 mb
![Page 11: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/11.jpg)
GFS resolution (vertical function)
NEMS/GFS Modeling Summer School 11
pres
sure
(P
a)
thickness (Pa)
![Page 12: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/12.jpg)
GFS resolution (vertical section)
NEMS/GFS Modeling Summer School 12
pres
sure
(P
a)
thickness (Pa)
GFS 64 hybrid levels on a cross-section along 90 E
![Page 13: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/13.jpg)
GFS in NCEP production
NEMS/GFS Modeling Summer School 1313
‘Mostly’Satellite+Radar
North AmericanMesoscale
NMM
North American Ensemble Forecast System
GlobalForecastSystem
Rapid Refreshfor AviationARW + GSI
CLIMATE CFS
~3.5B Obs / Day
GFS + MOM3/4
Global DataAssimilation
Air Quality
NMM + ARW
Dispersion, Ash,Smoke & DustARL’s HYSPLIT
Severe Weather
OceansHYCOM
WaveWatch III
NAM + EPA/ ARL’s CMAQ
Hurricane GFDL
HWRF (NMM)
Regional DataAssimilation
NMM + ARW +ETA + RSM
GEFS + Canadian Global +… Very Short Range Ensemble ForecastsTime-Lagged RR+NAM
Short-RangeEnsemble Forecast
![Page 14: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/14.jpg)
GFS & GDAS workflow(timing and dependencies)
NEMS/GFS Modeling Summer School 14
![Page 15: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/15.jpg)
GFS & GDAS workflow (jobs)
NEMS/GFS Modeling Summer School 15
NEMS N
EMS
NEMS
![Page 16: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/16.jpg)
GSM time split concept
GSM does numerical prediction by integrating a series of timesteps.
T574 Eulerian has a 2 minute timestep.Each timestep in the GSM is split by
computing and integrating “Dynamics” processes first and then computing and integrating “Physics” processes.
NEMS/GFS Modeling Summer School 16
![Page 17: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/17.jpg)
GSM time split Dynamics
Ideal gas law Conservation of mass
Transport (aka advection) Conservation of momenturm
Pressure gradient force (including mountain torque) Coriolis force Gravity (indirectly in hydrostatic approximation)
Conservation of energy (1st law) Energy conversion term
Cascade to unresolved scales (2nd law)
NEMS/GFS Modeling Summer School 17
![Page 18: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/18.jpg)
GSM time split Physics
Radiation (solar and terrestrial) Surface exchange (land, sea, ice) Turbulence (surface, boundary, and free) Subscale gravity waves Tracer sources and sinks Moist processes
Large-scale condensation Shallow convection Deep convection
NEMS/GFS Modeling Summer School 18
![Page 19: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/19.jpg)
NEMS, what is that?
NOAA Environmental Modeling SystemA shared, portable, high performance
software superstructure and infrastructure
For use in operational prediction models at NCEP
NEMS/GFS Modeling Summer School 19
![Page 20: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/20.jpg)
NEMS motivation
Develop a common superstructure for all NCEP models.
Modularize large pieces of the models with ESMF components and interfaces, and couple using NUOPC layers and wrappers.
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.
NEMS/GFS Modeling Summer School 20
![Page 21: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/21.jpg)
NEMS structure
NEMS/GFS Modeling Summer School 21
MAIN
EARTH(1:NM)
Ocean Atm Ice
NEMS
Ensemble Coupler
All boxes represent ESMF components.
NEMSsuper-structure
NEMSlibraryWrt nemsio, …
![Page 22: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/22.jpg)
NEMS components
NEMS/GFS Modeling Summer School 22
NMM GSM FIM
Solver
Domains(1:ND)
Dyn Phy
GFS Phy
Chem
Physlib
column physics
Post
libpost.a
NAM mesoscale GFS global
Physics parameterizations Postprocessor
Other components:
Model components:
![Page 23: NEMS/GFS Overview Mark Iredell, Software Team Lead.](https://reader036.fdocuments.us/reader036/viewer/2022062305/56649cb05503460f9497459d/html5/thumbnails/23.jpg)
NEMS/GFS Overview is over.
Thanks.Questions?
NEMS/GFS Modeling Summer School 23