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Mesoscale NWP Model Intercomparisonfor The Maritime Continent :
Preliminary Results and Future Plans
Tri Wahyu Hadi
Atmospheric Science Research GroupFaculty of Earth Sciences and Technology
Institut Teknologi BandungINDONESIA
Acknowledgement
• Kyoto University Active Geosphere Investigationfor The 21st Century COE Program (KAGI 21) :Profs. T. Tsuda and S. Yoden
• Institute for Research and Community Services (LPPM), ITB : Prof. Emmy Suparka
• MEXT Special Coordination Funds for PromotingScience and Technology
• Research assistants and students : Nurjanna Joko T.,I Dewa G. A. Junnaedhi, Amry Widyatmoko
• Other supporting agencies and research collaborators
Outline
1.Background and Motivation
2.Previous works and some results :• Near real-time downscaling experiments• A numerical study on strong convective
system
3. Current works • Mesoscale NWP model intercomparison• Another study on strong convective system
4. Future Plans
Background and Motivation :Meteorological Disasters in The Maritime Continent of Indonesia
Small “twister” in Yogyakarta (http://www.detik.com and other web sites)
“Extreme” Winds
• Small scale but relatively strong transient weather disturbance
• Torrential rain due to mesoscale convective system
• Increasing frequency and intensity (?)
• Effort to reduce these disaster necessitates a high resolution NWP system
“Extreme” Rainfall
Flooding over wide area (Aceh 2006, Central Java 2008)
Severe floods in Jakarta, Jan/Feb 2002, Feb. 2007, Feb 2008
Previous Works and Some Results :Near Real-Time Downscaling Experiments (1)
Global domain
Data freely available on the internet,NCEP GFS global model output :• Horizontal resolution : 0.5° & 1° available• Vertical resolution : 24 sigma levels • Time resolution : 3 hr (downloaded at 6 hr
interval)• Prediction range : up to 384 hr (var. res.)• Number of output parameters : 128 • GRIB ver. 2 data format
Targetted regional model characteristics
• Coarse grid res. : 30 km x 30km• Finer grid res. : 10 km x 10 km• Vertical resolution : 32 sigma levels • Time resolution : 3 hr• Two-way nesting between coarse and
finer domain
(figure by JMA)
Regional Model domains
Previous Works and Some Results :Near Real-Time Downscaling Experiments (2)
NOAA
Dept. Inf. ScienceKochi University
Space Science and Engineering Center(SSEC) University of Wisconsin
Block A :Internet Resources
Dept. Atm. Sci. University of Wyoming
GFS Data
SondeData
MTSAT IR mages
MTSAT/GOESlatest images
Block B :Download Server
Regional model Preprocessing(if data is adequate)
Daily rainfall estimation
Model runup to 48-hour lead time prediction
Topgraphyand land-use data (fixed)
Post processing of regional model output
-Monitoring-Prediction -Nowcasting-Forcast Verification
Block D : Web Server
Postprocess
Block C : PC Cluster
??
Previous Works and Some Results :Near Real-Time Downscaling Experiments (3)
MM5 modeling system :Non-hydrostaticPrimitive equationsDeveloped by PSU/NCARFree software Parallel version with MPIModel Setup
- boundary-layer parameterization : MRF
- cumulus parameterization :Grell (30 km) & KF (10 km)
Downscaling without additional
input except refinement of tropography
Previous Works and Some Results :Near Real-Time Downscaling Experiments (4)
1200 UTC
0000 UTCThe system hasrecently beenupgraded resulting in reduced latency
NCEP-GFS Forecast Run at 1200 UTC
Download Time
2100 UTC
MM5 Forcast Run
1200 UTC
MM5 Regional Prediction effective forecast lead time
Data downloaded at 6 hr fcst interval
PC Cluster assembledinhouse : 8 nodesAMD Athlon 64;10 GB total memory4 TB total data storage
Previous Works and Some Results :Near Real-Time Downscaling Experiments (5)http://weather.geoph.itb.ac.id/
Previous Works and Some Results :Near Real-Time Downscaling Experiments (6)
pure downscaling
not much improvementin average error
Previous Works and Some Results :A Numerical Study of Strong Convective System (1)
Pwat (kg/m2)
TBB (K)
Synoptic scale conditionrelated to Jakarta flood event of Jan/Feb 2002
• Southward migrationof monsoon trough
• Appearance of cyclonicvortex over the Indian Oceansouth-west of Jakarta
Data : NCEP global tropospheric analysis and GMS IR imageries(daily averaged TBB)
Northern coastal plain of Java Island is prone to heavy rainfall during end of Jan.-beginning of Feb.
Previous Works and Some Results :A Numerical Study of Strong Convective System (2)
Rc (mm)
• MM5 daily accumulated rainfall
• 3 km horizontal resolution
• NCEP-FNL initial and boundary condition
Concentration of heavy rainfall over Jakarta area
Previous Works and Some Results :A Numerical Study of Strong Convective System (3)
TBB (K)
From Edvin Aldrian (BPPT), Courtesy of BMG
Characterized by North-Southmovement of convectivesystem
Previous Works and Some Results :A Numerical Study of Strong Convective System (4)
Clw (g/kg)
27 Jan 2002, 0200 LT 27 Jan 2002, 0300 LT
27 Jan 2002, 0400 LT 27 Jan 2002, 0500 LT
Convectivemechanism :
cold pooladvection
Previous Works and Some Results :A Numerical Study of Strong Convective System (4)
Clw (g/kg)
Convectivemechanism :
mixed layerblocking
Previous Works and Some Results :Anticipated Problems in NWP Application
• Model accuracy High resolution simulation using NWP model hasrevealed a detailed structure of the convective systemrelated to heavy rainfall events but downscaling alonedoes not seem to significantly improve average forecast error local data assimilation
• Model uncertaintyModel uncertainty is an inherent problem of atmospheric predictability quantification by meansof (multi-model) ensemble forecasting learning from other projects, model intercomparisons is an important step
Current Works :Mesoscale NWP Intercomparison (1)
JMA
CMA
MSC
ZAMG
NCEP
CMAS
BRDP08, Courtesy of Dr. Hiromu Seko (MRI-JMA)
Current Works :Mesoscale NWP Intercomparison (2)
Improvement of Computational Infrastructure
The same look and number of nodes but now with :
• Processor : Intel Core2 Quad Core(2.4 GHz) per node (32 cores in total)
• 32 GB of total memory• OS : Open SuSE 10.2 (free version)
PC Cluster assembled inhouse : • 8 nodes (1 master and 7 diskless nodes)
• Processor : single AMD Athlon (2.0 GHz) per node
• 10 GB total memory• OS : SLES 9.0
MM5 and WRF test runs show that Hybrid SMP-MPI system reduce computational time by a factor of 4 to 6
Current Works :Mesoscale NWP Intercomparison (3)
MM5-WRF output samples
• Apart from accuracies, MM5 andWRF produced quite results at 30 km resolution downscaling
• WRF accumulated rainfall is morecharacterized wih small scale features
Current Works :Mesoscale NWP Intercomparison (4)
WRF 3km simulation of heavy rainfall
WRFMM5
Rc (mm)
Current Works :Mesoscale NWP Intercomparison (5)
WRF with cumulus parameterization WRF explicit
• Convection initiated at the top of PBL• Gravity-wave induced convection (?)• Sensitivity to cumulus parameterization at 3 km resolution
Current Works :Another Study of Strong Convective System (1)
http://foto.okezone.com/
0104 07
Floods in Karawang :• Long duration of inundation (more than 10 days)
• Relatively large area• Seems to be triggered by rainfall event of Feb. 6, 2008
• Less effect of topography(?)
Current Works :Another Study of Strong Convective System (2)
2008/02/06 21:06 2008/02/06 22:062008/02/06 19:06 2008/02/06 20:06
2008/02/07 00:062008/02/06 22:30 2008/02/06 23:06 2008/02/06 23:30
2008/02/07 00:30 C-band Radar Images Courtesy of HARIMAU Project(JAMSTEC-BPPT)
Eastward moving convective cells along the coastal plain
Current Works :Another Study of Strong Convective System (3)
30-hour forecast of 3-hourly convective rainfall (07/02/2008 0100 LT)
MM5 WRF
• New resolution set-up 27-9-3 km nesting (2 online and 1 off-line) • Another type of blocking (land-breeze?) • Too strong blocking in WRF• WRF requires more parameter tuning
Future Plans : Three-model Intercomparisons with JMA-NHM
06 February 2008, JMA-NHM test run 24 and 30 hour forecast of 3-hourly precipitation, 27 km resolution
JMA-NHM has been installed and being tested to run donwscaling forecast with NCEP-GFS data
Future Plans : Coal Mines at Berau as Forecast Test Ground
• Partial funding by PT. Berau Coal
• Installation of 6-7 AWS
• Near real time data transfer to ITB
• Experiments on local data assimilation
• Decision support system in mining opration as apart of research activities
Future Plans : C-Band Radar and GPS/Met over West Java
• Another high-resolutionsimulation and forecast test ground
• Relatively dense GPSnetwork as part of INATEWS
• High possibility to obtain near real-time GPS/Metdata through collaborationwith BAKOSURTANAL (National Survery and MappingAgency)
• More powerful if combined withC-band radar at Serpong through collaboration with JAMSTEC
Courtesy of Cecep Subarya (BAKOSURTANAL)
Concluding Remarks
• Capacity building We have developed an entry-level computational infrastructure to conduct NWP research in SEA(The Maritime Continent of Indonesia). We are setting upan environment for model intercomparison
• Near-real time downscaling experimentsMM5-WRF intercomparison shows that WRF requiresmore model parameter tuning in the tropics
• Process study Strong convections related to heavy rainfall involve complex mechanisms
• Future plan We are trying to setup two ground tests for model intercomparison (Berau and Jakarta)