module 6 mm5: overview william j. gutowski, jr. iowa state university

Module 6 Module 6 MM5: OverviewMM5: Overview

William J. Gutowski, Jr.William J. Gutowski, Jr.Iowa State UniversityIowa State University

GOALS:GOALS:Flow of information in MM5 systemFlow of information in MM5 systemTasks of individual codesTasks of individual codesEmphasis on climate simulation Emphasis on climate simulation


OUTLINE:OUTLINE:

Overall SystemOverall System

PreprocessingPreprocessing

MM5 detailsMM5 details


OUTLINE:OUTLINE:



REGRID

INTERPF

MM5 Modeling System

Preprocessing

TERRAIN

REGRID

INTERPF

MM5

MM5 Modeling System

Preprocessing

Simulation

TERRAIN

REGRID

INTERPF

MM5

Output Analysis

MM5 Modeling System

Preprocessing

Simulation

Postprocessing

TERRAIN

GRAPH/RIP

TERRAIN

REGRID

MM5

Output Analysis

MM5 Modeling System

RAWINS/little_r

INTERPB

NESTDOWN

INTERPF

GRAPH/RIP

MM5 Coordinates: Vertical

σ = p- ptop( ) psurf -ptop( )

σ =1

σ =0ptop

psurf

MM5 Coordinates: Vertical

σ = p- ptop( ) psurf -ptop( )

σ =1

σ =0ptop

psurf

˙ σ ,w

u,v,T,q,p'

MM5 Coordinates: Horizontal

I

J(1,1)

(IMAX,JMAX)


X X X

X X X

X X X

I

J(1,1)

(IMAX,JMAX)


X X X

X X X

X X X

I

J(1,1)

(IMAX,JMAX)

u,v

T,q,p’,wArakawa

B-grid

MM5 Modeling System

How does a “flat” grid ...

X X

X X

MM5 Modeling System

How does a “flat” grid ...

...represent part of the spherical earth?

X X

X X ?

MM5 Modeling System

By projection to a flat plane

MM5 Modeling System

PolarStereographic

True at 90o

MM5 Modeling System

Lambert Conformal

True at, e.g.,30o and 60o

MM5 Modeling System

Mercator

True at 0o

MM5 Modeling System

Map Factor:m = (distance on grid)/(distance on earth)

MM5 Modeling System

Forcing Frame:for lateral

boundary conditions“free” interior

MM5 Modeling System

Other Features: • Nonhydrostatic

• Grid nesting

dwdt

−u2 +v2

a=−

1ρ

∂p∂z

+2Ωucosφ −g+Frz

OUTLINE:OUTLINE:




REGRID

INTERPF

Preprocessing

Preprocessing

TERRAIN

Preprocessing

Data preparation: topography land use gridded, 3-D atmospheric fields

wind temperature humidity geopotential height

initial surface conditions soil moisture soil temperature

(direct observations)

Preprocessing

TERRAIN(1) establishes model domain and grid(2) interpolates topographic and land use data to model grid

Preprocessing

TERRAIN domain specifications:• projection

Preprocessing

TERRAIN domain specifications:• projection• central latitude/longitude

Preprocessing

TERRAIN domain specifications:• projection• central latitude/longitude• # of grid points

(IMAX,JMAX)

Preprocessing

TERRAIN domain specifications:• projection• central latitude/longitude• # of grid points• grid spacing

(IMAX,JMAX)

X, Y

Preprocessing

TERRAIN input:1. Topographic data

• 1o

• 30 min.• 10 min.• 5 min.• 30 sec.

Preprocessing

TERRAIN input:

2. Land use/vegetation data

• PSU/NCAR (13 categories,

global)

• SiB (17 categories, North

America)

• USGS (25 categories, global)

Preprocessing

TERRAIN input:

3. Land/water mask

• SiB (North America)

• USGS (global)

Preprocessing

TERRAIN input:

4. Soil texture

5. Monthly vegetation fraction

6. Deep soil temperature

Preprocessing

TERRAIN interpolation options:

• 16-point, 2-D overlapping parabolic fit

(all TERRAIN fields)

• Cressman-type objective analysis

(topography only)

Preprocessing

TERRAIN output files:

terrestrial data files

printout (run information) file

plot file in NCAR Graphics format

REGRID

INTERPF

Preprocessing

Preprocessing

TERRAIN

Preprocessing

REGRIDInterpolates gridded atmospheric data horizontally to model grid

Preprocessing

REGRID input:• TERRAIN output• Atmospheric analysis on pressure levels

Preprocessing

REGRID output:• Atmospheric data on model’s horizontal grid (on pressure levels)

REGRID

INTERPF

Preprocessing

Preprocessing

TERRAIN

Preprocessing

INTERPF•Interpolates atmospheric data vertically to

model grid•Generates surface fields: pressure, air

temperature•Initializes nonhydrostatic model

Preprocessing

INTERPF1. Ingest REGRID output2. Interpolate vertically to coordinate3. Output initial conditions & lateral

boundary conditions

OUTLINE:OUTLINE:



MM5 detailsMM5 details


REGRID

INTERPF

MM5

MM5 details

Preprocessing

Simulation

TERRAIN

Conservation laws:(1) Projected to model grid(2) Transformed to sigma coordinates

MM5 details

dudt

−uvtanφ

a+

uwa

=−1ρ

∂p∂x

+2Ωvsinφ−2Ωwcosφ+Frx

∂u∂t

+mρ

(∂ ′ p ∂x

−σp*

∂p*∂x

∂ ′ p ∂σ

) =

−V ⋅∇u+v( f +u∂m∂y

−v∂m∂x

)−ewcosα −uwrearth

+Du

Earlier:

Tutorial, p.8-4:

Time Stepping:

MM5 details

t t

n-1 n n+1

T, q, advection, physics, boundary, coriolis, diffusion terms

Long (leapfrog) step

Split-explicit Time Stepping:

MM5 details

t t

n-1 n n+1

T, q, advection, physics, boundary, coriolis, diffusion terms

pressure gradients, divergence terms

Short (forward) step

Long (leapfrog) step

MM5 details

Convection parameterization

Options -• None• Anthes-Kuo• Grell• Arakawa-Schubert• Fritsch-Chappell• Kain-Fritsch• Betts-Miller• Shallow Cumulus

MM5 details

Explicit Moisture Schemes

Options -• Dry• Stable• Warm microphysics• Simple ice• Mixed phase• Goddard• Reisner graupel• Schultz microphysics

Planetary Boundary Layer Schemes

MM5 details

Options -• None• Bulk• High-Res. Blackadar• Burk-Thompson• Eta • MRF• Gayno-Seaman

MM5 details

Radiation Schemes

Options -• None• Simple cooling• Cloud-radiation• CCM2• RRTM longwave

MM5 details

Land Surface Schemes

Options -• None•Force-Restore• Five-Layer Soil• OSU/Eta Land-Surface Model

MM5 details

Scheme Couplings

RadiationRadiation

SurfaceSurface

Explicit MoistureExplicit Moisture ConvectionConvection

PBLPBL

cloud

moistening

downward SW & LW

upward LW& albedo

sfc. fluxes

sfc. T,q,wind

REGRID

INTERPF

MM5

Output Analysis

MM5 Modeling System

Preprocessing

Simulation

Postprocessing

TERRAIN

GRAPH/RIP

module 6 mm5: overview william j. gutowski, jr. iowa state university

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