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MM5 (UoH-UK): Fifth Generation PSU/NCAR Mesoscale Model

General information

Model name and version

short nameMM5 (UoH-UK)
full nameFifth Generation PSU/NCAR Mesoscale Model
revision
date
last change

Responsible for this information

nameYe YU
instituteUniversity of Hertfordshire
addressSTRI, University of Hertfordshire, College Lane, Hatfield, AL10 9AB, UK
zip
city
countryUnited Kingdom
phone0044 01707284052
fax0044 01707284185
e-maily.e.yu(belongs-to)herts.ac.uk

Additional information on the model

Contact person for model code

same as person above
name
institute
divisions
street
zip
city
country
phone
email
fax

Model developer and model user

developer and userPenn State University and NCAR, USA as a community mesoscale model with contributions from users worldwide.

Level of Knowledge needed to operate model

basic
intermediate
advanced
remarks

Model use at your institution

operational
for research
other use

Model code available?

is available?yes
more detailsfree software, open code

Minimum computer resources required

typePC
time needed for rundepends on individual cases
storage200G

Further information

documentationGrell, G. A., J. Dudhia and D. R. Stauffer, 1994: A description of the fifth-generation Penn State/ NCAR mesoscale model (MM5). NCAR Technical Note, NCAR/TN-398+STR, 117 pp. Guo, Y.-R., and S. Chen, 1994: Terrain and land use for the fifth-generation Penn State/NCAR mesoscale modeling system (MM5). NCAR Technical Note, NCAR/TN-397+IA, 114 pp. Haagenson, P. L., J. Dudhia, G. A. Grell and D. R. Stauffer, 1994: The Penn State/NCAR mesoscale model (MM5) source code documentation. NCAR Technical Note, NCAR/TN-392+STR, 200 pp.
model referencesMellor, G.L. and T. Yamada, 1982: Development of a turbulence closure model for geophysical fluid problems. Rev. Geophys. Space Phys., 20, 851-875. Deardorff, J. W., 1972: Parameterization of the planetary boundary layer for use in general circulation models. Mon. Wea. Rev., 100, 93-106. Blackadar, A. K., 1976: Modeling the nocturnal boundary layer. Preprints of Third Symposium on Atmospheric Turbulence and Air Quality, Raleigh, NC, 19-22 October 1976, Amer. Meteor. Soc., Boston, 46-49.
webpagehttp://www.mmm.ucar.edu/mm5/
additional information

Model properties

Model type

2D
3D
meteorology
chemistry & transport

Model scale

microscale
mesoscale
macroscale
short term
long term

Meteorological variables

PrognosticDiagnostic
u
v
w
ζ
pv
T
θ
θl
p
Gph
ρ
qv
qt
qlc
qf
qsc
qlr
qsh
qsg
qss
N
E
ε
K
zi
other variables iperturbation pressure
other variables ii
other variables iii

Approximations

Boussinesq
anelastic
hydrostatic
flat earth
remarks

Parametrizations

Meteorology

turbulence schemeNon-local vertical mixing scheme based on Blackadar scheme; Local high-order TKE prognostic scheme based on Mellor-Yamada (1982) formulas.
deep convection
surface exchangeBulk-aerodynamic parameterization or similarity theory
surface temperaturecomputed from a surface energy budget that is base on the 'force-restore' method developed by Blackadar(Zhang and Anthes 1982); Five-Layer Soil; Noah Land-Surface Model or Pleim-Xiu Land-Surface Model
surface humidityBulk-aerodynamic parameterization or similarity theory
radiationbroadband emissivity method taking into account water vapor, carbon dioxide,ozone and cloud
unresolved orographic drag
radiation in vegetation
radiation between obstacles
treatment of obstacles
clouds / rainNonconvective precipitation scheme; Warm Rain; simle ice; Mixed-Phase; Goddard microphysics; Reisner graupel;Schultz microphysics
remarks

Initialization & boundary treatment

Initialization

chemistry & transport
meteorologyThe model first generates a hydrostatic input file on the hydrostatic sigma levels which is based on actual surface pressure, not reference pressure. To initialize the data for the nonhydrostatic model a further small vertical interpolation is needed to move to the nonhydrostatic sigma levels. This involves first calculating the heights of the hydrostatic levels, then doing a linear-in-height interpolation of u, v, T and q to the nonhydrostatic levels. Vertical velocity (w) is simply calculated from the pressure velocity (ω) obtained by integrating horizontal velocity divergence vertically while still on the hydrostatic sigma levels. This ω is then interpolated to the nonhydrostatic levels and converted to w (w=-ω/ρg). Pressure perturbation (p′) is initialized to give a hydrostatic balance. Once virtual temperature is known on the nonhydrostatic model levels, the model’s vertical velocity equation in finite difference form is used with the acceleration and advection terms set to zero. This leaves a relation between Tv(z) and the vertical gradient of p′. Given the sea level pressure, p′ at the lowest sigma level can be estimated, and then given the profile of virtual temperature vertical integration gives p′ at the other levels. This balance ensures that the initial vertical acceleration is zero in each model column.

Input data (name sources for data, e.g. website)

orographyUS Geological Survey data
land useUS Geological Survey data
obstacles
vegetation
meteorologyNCEP GLOBAL TROPO ANALS/NCEP Final Analysis/NCEP Global Reanalysis/ECMWF Global Reanalysis/ECMWF Global Operational analysis
concentrations
emissions
remarks

Data assimilation

Meteorology
nudging technique
adjoint model
3D-VAR
4D-VAR
OI
detailsA continuous (every model time step) dynamical assimilation is used where forcing functions are added to the governing model equations to gradually 'nudge' the model state toward the observations.

Boundary conditions

Meteorology
surfaceMany options are available: single slab with fixed-temperature substrate or five layer soil model base on the 'force-restore' method developed by Blackadar;Pleim-Xiu Land-Surface Model;Noah Land-Surface Model
topRadiative boundary conditions
lateral inflowseveral options are available: fixed; Sponge Boundary Conditions;Nudging Boundary Conditions
lateral outflowseveral options are available: fixed; Sponge Boundary Conditions;Nudging Boundary Conditions

Nesting

Meteorology
one way
two way
other
variables nested
nesting online
nesting offline
data exchange by array
data exchange by file
time step for data exchangeevery time step
explain methodFor one way nesting, domain output from courser domain can be put into NESTDOWN to create an input file with higher resolution (any integer ratio in dx) and new lateral and lower boundary files for higher resolution domains. For two-way nesting,multiple domains is run at the same time using 2-way interactive mesh refinement scheme.
variables nested
other

Solution technique

Coordinate system and projection

Horizontal

cartesian
Lambert conformal
latitude / longitude
rotated lat. / long.

Vertical

z coordinate
surface fitted grid
pressurecoordinate
sigma coordinate
remarks

Numeric

Meteorology

Grid

Arakawa A
Arakawa B
Arakawa C
Arakawa D
Arakawa E
uniform grid
nonuniform grid
Euler

Time integration

explicit
split-explicit
semi-implicit
other

Spatial discretisation

momentum equations
scalar quantities
additional informationFor time integration, time-splitting scheme is used on fast terms, forward step is used for diffusion and microphysics. Some radiation and cumulus options use a constant tendency over periods of many model timesteps and are only recalculated every 30 minutes or so.
other

Model resolution

Meteorology

HorizontalVertical
max
min

Domain size

Meteorology

HorizontalVertical
max
min

Model Validation and Application

Validation & evaluation

Used validation & evaluation methods

analytic solutions
evaluated reference dataset
model intercomparison
additional validation & evaluation efforts
remarks

Application examples

application examplescyclone and cold front convective systems land surface processes air pollution meteorology

Participation in specific model evaluation exercises

AQMEII
List experiments (AQMEII)
Cost728
List experiments (COST728)
HTAP
List experiments (HTAP)
MEGAPOLI
List experiments (MEGAPOLI)