the mm5: structure and applications

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The MM5: Structure and Applications Jordan Powers Mesoscale and Microscale Meteorology Division NCAR March 30, 2000 I. BACKGROUND II. THE MM5 MODELING SYSTEM III. MODEL APPLICATIONS

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The MM5: Structure and Applications. Jordan Powers Mesoscale and Microscale Meteorology Division NCAR March 30, 2000 I. BACKGROUND II. THE MM5 MODELING SYSTEM III. MODEL APPLICATIONS. I. BACKGROUND. MM5: FIFTH-GENERATION PENNSYLVANIA STATE - PowerPoint PPT Presentation

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Page 1: The  MM5:  Structure  and  Applications

The MM5: Structure and Applications

Jordan Powers

Mesoscale and Microscale Meteorology Division

NCARMarch 30, 2000

I. BACKGROUND

II. THE MM5 MODELING SYSTEM

III. MODEL APPLICATIONS

Page 2: The  MM5:  Structure  and  Applications

I. BACKGROUND• MM5: FIFTH-GENERATION PENNSYLVANIA STATE UNIVERSITY / NCAR MESOSCALE MODEL 5

• 3D, NONHYDROSTATIC, PRIMITIVE EQUATION MODEL

• MM5 SYSTEM Suite of programs designed to

(i) prepare (ii) produce (iii) analyze

a meteorological simulation

• USE a) Research ( historical simulations ) b) Forecasting ( real-time operation )

Page 3: The  MM5:  Structure  and  Applications

• ORIGINS Regional model for air quality study

( Anthes and Warner 1978: Mon. Wea. Rev., 106, 1045–1078 )

MM4: Early 1980’s–1993 Nonhydrostatic version developed in 1993

( Dudhia 1993: Mon. Wea. Rev., 121, 1493-1513 )

• DEVELOPMENT

Version 1: 1993–1996 Version 2: 1996–1999 Version 3: July 1999

New releases every 3–4 months

Page 4: The  MM5:  Structure  and  Applications

• MESOSCALE MODELS — A PARTIAL LIST Model Developing and / or Implementing

Institution

Eta, NGM NCEP Community Meso. Model, RFE AES ( Canada )

ECMWF Model ECMWF UKMO Model U.K. Met. Office ALADIN Meteo-France HIRLAM Met Services: Ireland, Sweden, Finland, Denmark, Spain JLASM Japanese Met. Agency CSIRO LAM Australia Lokalmodell Deutsch Wetterdienst ( Germany )

MM5 NCAR / Penn State RAMS Colorado State ARPS Univ. Of Oklahoma COAMPS U.S. Navy / NRL RUC NOAA / Forecast Systems Lab

Page 5: The  MM5:  Structure  and  Applications

• MM5 COMMUNITY

– >580 users on mailing list

– 211 user institutions

57 U.S. Universities

36 federal and state agencies

85 (foreign) institutions (30 countries)

33 private companies

Page 6: The  MM5:  Structure  and  Applications

II. THE MM5 MODELING SYSTEM

1) MM5 ATTRIBUTES

• NESTED GRID MODEL

– Multiple nests allow for high resolution over key areas

– Grids movable, grids may overlap

– Generally 3:1 coarse:fine grid size and time step ratios ( 2-way nesting )

– 2-way v. 1-way nesting

2-way: Nest receives input from coarser mesh via its boundaries & nest feeds back to coarser mesh

1-way: Nest receives BC’s from boundary files produced by the coarser mesh, but no nest feedback to coarser mesh

Page 7: The  MM5:  Structure  and  Applications

Example of an MM5 nesting configuration

Domain 1 = coarsest grid, level 1Domains 2,3 = level 2Domain 4 = level 3Domains 2,3 = overlapping grids

Page 8: The  MM5:  Structure  and  Applications

• VERTICAL COORDINATE:

– Terrain-following

( cf. Eta model– step coord )

– = p – ptop

psfc – ptop

– ptop = const

(e.g., 50 mb, 100 mb)

– = 1 ( sfc )

0 ( top )

Page 9: The  MM5:  Structure  and  Applications

2) MM5 PHYSICS Multiple options for atmospheric processes

• NONHYDROSTATIC PHYSICS Nonhyd effects important for x 5 km

• MOIST PROCESS TREATMENTS

EXPLICIT SCHEMES

a) Grid-scale ( resolved ) precip

b) Operate upon grid point saturation

Page 10: The  MM5:  Structure  and  Applications

Available explicit packages

– Warm rain

• Prognostic eqns. for cloudwater (CLW), rainwater (RNW)

– Simple ice: Dudhia

• CLW, RNW for T>0C; cloud ice, snow for T<0° C

– Mixed-phase: Reisner 1

• Prognostic eqns. for CLW, RNW, ice, snow

– Mixed-phase: Reisner 2, Goddard

• Prognostic eqns. for CLW, RNW, ice, snow, graupel,

ice no. concentration

NB: Memory requirements and computational time increase with

increasing scheme complexity

Page 11: The  MM5:  Structure  and  Applications

CUMULUS PARAMETERIZATIONS

a) Subgrid-scale ( parameterized ) precip

b) Schemes account for:

(i) precip, heating from convection when grid unsaturated

(ii) vertical fluxes of heat, moisture, momentum on the

unresolved convective scale

– Kuo

• moisture convergence trigger function ( TF )

• prescribed heating profile

– Arakawa-Schubert

• large-scale destabilization TF

• cloud populations assumed

– Fritsch-Chappell

• vertical velocity / temp. perturbation TF

• single cloud / grid box

Page 12: The  MM5:  Structure  and  Applications

CUMULUS PARAMETERIZATIONS

– Betts-Miller

• designed to represent quasi-equilibrium established by

deep convection on large scales in tropics

• adjusts to a given post-convective profile

– Grell 2

• lifting depth TF

• single cloud / grid box

• moist downdrafts

– Kain-Fritsch

• vertical velocity / temp. perturbation TF

• cloud-mixing scheme to determine entrainment/detrainment

• all available buoyant energy removed in relaxation time

Page 13: The  MM5:  Structure  and  Applications

• PBL OPTIONS

– Bulk PBL scheme

• coarse vertical resolution in boundary layer

– Blackadar high-resolution scheme

• high vert res in boundary layer

• Bulk Ri dependent PBL regimes

– Burk-Thompson scheme

• coarse or high res in boundary layer

• TKE predicted

– MRF model scheme

• high vert res in boundary layer

• similar to Blackadar, but more efficient computationally

• used in conjunction with 5-layer soil model

Page 14: The  MM5:  Structure  and  Applications

• PBL OPTIONS

– Gayno-Seaman

• based on Mellor-Yamada TKE prediction

• use of liquid water potential temperature as conserved

variable (for more accurate simulation of PBL in

saturated conditions)

– Eta model scheme

• based on Mellor-Yamada TKE prediction

Page 15: The  MM5:  Structure  and  Applications

• LAND SURFACE SCHEMES

– Force / restore ( slab / Blackadar )

• single slab and fixed-temp substrate

• slab temp based on energy budget

– 5-layer soil model

• temp predicted in layers, with fixed substrate below

• vertical temp diffusion eqn. used

– MM5 land surface model ( LSM )

• uses high-res ( 1-km ) vegetation and soil data

• results show improved reproduction of diurnal variations

in sensible / latent fluxes, skin temp, and soil moisture

Page 16: The  MM5:  Structure  and  Applications

Diurnal cycle: Comparison of 2-meter temperature for MM5 with

slab surface model, MM5 with Land Surface Model (LSM), and

observations from FIFE.

Page 17: The  MM5:  Structure  and  Applications

qv

(g/kg)

MM5-simulated mixing ratio at lowest model level compared to FIFE

observations. Slab model, LSM, and obs qv shown.

Page 18: The  MM5:  Structure  and  Applications

3) MM5 OPERATION

• STAGES

(1) Preprocessing Input data preparation

(2) Processing Compilation and simulation

(3) Postprocessing Analysis of output

• PREPROCESSING

Step MM5 System Program

a) Prepare model terrain ‘Terrain’

b) Prepare 1st guess field ‘Regrid’

c) Reanalyze 1st guess w/ obs ‘Little-r’ ( future: 3DVAR )

d) Interpolate input to -levels ‘Interp’

Page 19: The  MM5:  Structure  and  Applications
Page 20: The  MM5:  Structure  and  Applications

• PROCESSING

a) Compilation

– F77, F90

b) Execution

– MM5 operable on both shared memory parallel ( SMP )

& distributed memory parallel ( DMP ) architectures

– High-performance computer / workstation platforms:

SGI, Compaq / DEC, HP, Sun, Cray, Fujitsu, IBM

– MM5 operable on PC’s or laptops

Page 21: The  MM5:  Structure  and  Applications

• POSTPROCESSING

– Model output visualization and analysis done with

(generally batch mode) graphics software

– Plotting packages

‘Graph’ ( official MM5 plotting software;

NCAR Graphics req’d )

‘RIP’ ( NCAR Graphics req’d )

‘VIS5D’ ( interactive )

‘Gempak’

Page 22: The  MM5:  Structure  and  Applications

4) MM5 USER INFORMATION

• GENERAL INFORMATION

– http:// www.mmm.ucar.edu / mm5

• MM5 SYSTEM ACQUISITION

ftp ftp.ucar.edu

cd ~mesouser / MM5V3

• DOCUMENTATION

– Sources and info: http:// www.mmm.ucar.edu / mm5 / doc.html

– Main references

“A Description of the Fifth-Generation Penn State / NCAR

Mesoscale Model 5 (MM5)” ( Grell et al. 1994 )

“PSU / NCAR Mesoscale Modelling System Tutorial Class Notes”

Page 23: The  MM5:  Structure  and  Applications

• MM5 MEETINGS

– Info: http:// www.mmm.ucar.edu / mm5 / whatisnew.html

– Events ( @ NCAR— Boulder, CO )

Annual MM5 Users’ Workshop ( June )

MM5 Tutorials ( Jan., June )

Page 24: The  MM5:  Structure  and  Applications

III. MODEL APPLICATIONS

1) Coastal dynamics/microphysics — Heavy coastal fog (Scotland)

2) Salt breeze — Circulations amid complex terrain (Great Salt Desert)

3) Tropical extreme precip — Explicit v. parameterized precip (Hong Kong)

4) Typhoon simulation — Forecast track investigation (Western Pacific)

5) Real-time forecast (U.S. / Colorado)

Page 25: The  MM5:  Structure  and  Applications

Heavy Coastal Fog: Simulation of the Haar

• Attempt to simulate phenomena of heavy North Sea fog along Scottish coast ( “haar” )

• 30 km / 10 km nested grid configuration

• High vertical resolution: 38 half- levels

Sfc — 100 mb

smallest z 12 m

• Success in capturing fog and diurnal cycle of inland penetration

Page 26: The  MM5:  Structure  and  Applications

Distribution of the Scottish haar

NOAA-8 1448 GMT 27 APRIL 1984

NOAA-7 0836 GMT 27 APRIL 1984

Satellite imagery for 0836 UTC (top) and1448 UTC (bottom) 27 April 1984

Page 27: The  MM5:  Structure  and  Applications

MM5 forecasts of the Scottish haar. Near-surface wind (vectors) andcloudwater (shading) and integrated cloudwater (bold contour) for0830 UTC (8.5-hr fcst) and (b) 1445 UTC (14.75-hr fcst) 27 April 1984.

(a) (b)

Page 28: The  MM5:  Structure  and  Applications

High-resolution, real-time forecasts of circulations in complex terrain: The salt breeze

• Application: Real-time MM5 systems developed for U.S. Army for forecasting at Test Ranges

• 30 km / 10 km / 3.3 km / 1.1 km nested grid configuration overDugway Proving Ground, Utah

• Very good short-term fcst of salt breeze through application ofhigh horizontal resolution

Page 29: The  MM5:  Structure  and  Applications

4-domain configuration of real-time MM5 for simulations over

complex terrain of western Utah.

( Real-time forecast cycle timeline shown at bottom )

Page 30: The  MM5:  Structure  and  Applications

10-hour MM5 forecast on Domain 3 (3.3 km) of near-surface

winds (vectors) and potential temperature (shaded) valid 2200

UTC 9 September, 1997. Location of 1.1-km grid (Domain 4)

shown.

Page 31: The  MM5:  Structure  and  Applications

Analysis of surface streamlines from Utah mesonet data over

area of 1.1-km grid for 0000 UTC 10 September 1997. Salt

breeze boundary extends W–E through middle of region.

Page 32: The  MM5:  Structure  and  Applications

10-hour forecast on 1.1 km grid of near-surface wind (vectors)

and potential temperature (shaded) valid 2200 UTC

9 September 1997.

Page 33: The  MM5:  Structure  and  Applications

Tropical extreme precipitation: Explicit v.parameterized precip and the moist process“gray area”

• Case: Series of MCS’s passing over Hong Kong 8–9 June 1998

• Observed 24-hr rainfall: 408 mm

• MM5 simulation with 54 / 18 / 6 km grid configuration

• No Cu parameterization on 6-km grid ( fully-explicit moist processes)

Page 34: The  MM5:  Structure  and  Applications

MM5 simulation showing effects of lack of Cu param on fine grid.Total precip shaded. 18-km grid shown; outline of 6-km nestappears in left center. (a) Simulation hr 6, valid 18 UTC 8 June 1998.1998. (b) Simulation hr 9, valid 21 UTC 8 June 1998.

Area seen is southern China coast around Hong Kong.

Hour 6 Hour 9(a) (b)

Page 35: The  MM5:  Structure  and  Applications

MM5 simulation showing effects of lack of Cu param on fine gridTotal explicit precip blue; total parameterized precip red.18-km grid shown; outline of 6-km nest appears in left center.(a) Simulation hr 6, valid 18 UTC 8 June 1998. (b) Simulation hr 9,valid 21 UTC 8 June 1998.

Area seen is southern China coast around Hong Kong.

Hour 6 Hour 9(a)

(b)

Page 36: The  MM5:  Structure  and  Applications

Tropical cyclone forecasting: Predictions of typhoon track

• Operational MM5 forecast system ( 135 / 45 / 15 km ) in Taiwan consistent in tracking Typhoon Sam ( Aug 1999 ) northward

( instead of WNW ) from genesis region

• TD developed east of northern Philippines 19 Aug 1999

• Observed track of Sam westward / northwestward track acrossSouth China Sea with landfall in Hong Kong area 22 Aug

• Crash of China Airlines Flt. 642 ( fatalities ) upon landing inHong Kong in gale force winds from Sam

Page 37: The  MM5:  Structure  and  Applications

Observed (red) and modeled (blue) tracks of Typhoon Sam,Aug 1999. Positions every 12 hours marked. Periods shownare Aug 12 UTC—23 Aug 00 UTC (obsv’d) and 19 Aug 12 UTC— 22 Aug 12 UTC (model).

Page 38: The  MM5:  Structure  and  Applications

Analyzed and 12-hr MM5 forecast SLP for Typhoon Sam, valid 00 UTC20 Aug 1999. Contour interval = 1 mb. Window of domain 2 of 3-domain configuration shown; grid resolution = 45 km.(a) Analysis. (b) 12-hr forecast.

(a) (b)

Page 39: The  MM5:  Structure  and  Applications

12-hr MM5 forecast – analysis wind differences at 00 UTC 20 Aug 1999 forTyphoon Sam showing forcing in South China Sea. Difference vectors shown.Wind speed difference contoured; dashed= negative ( fcst<analyzed );solid= positive ( fcst>analyzed ); contour interval= 2.5 m/s. Window of domain 2of 3-domain configuration shown; grid resolution = 45 km. (a) 700 mb. (b) 500 mb.

(a) (b)

Page 40: The  MM5:  Structure  and  Applications

Real-time NCAR MM5 forecast: Setup

• MMM MM5 Site: http:// rain.mmm.ucar.edu / mm5

• Runs – Main runs ( CONUS )

– Global run

– Hurricane run ( Aug.–Nov. )

• Configuration (main runs)

– 2 domains: 30 km ( CONUS ) 10 km ( Colorado & Rocky Mtn. West )

– Inits: 0000 UTC & 1200 UTC

– First-guess and boundary conds: Eta model

– Physics: Simple ice, Kain-Fritsch Cu param, MRF PBL scheme