View
217
Download
2
Tags:
Embed Size (px)
Citation preview
High-resolution numerical modelingand predictability of atmospheric flows
M. Ehrendorfer, A. Gohm and G. J. MayrInstitut für Meteorologie und Geophysik
Universität Innsbruck
Vortrag am Zweiter Mini-Workshop
Konsortium Hochleistungsrechnen
Universität Innsbruck, Austria12. März 2004
http://www2.uibk.ac.at/meteo
IMGI HPC workshop 2004
Outline
High-Resolution Numerical Modeling and Predictability of Atmospheric Flows
1. Atmospheric models
2. Stability of flows
specific error structures: singular vectors, data assimilation
3. Additional remarks
4. High-resolution modeling
• Past research: single-processor computing
• Current research: multi-processor parallel computing
• Introducing the numerical models
• Introducing the computing facilities
• An example: simulation of bora winds
• Outlook: numerical weather prediction for the Winter Universiade 2005
7 Variables: wind v, density , potential temperature pressure p, temperature T
budget equations: momentum, mass, energy
European Centre for Medium-Range Weather ForecastsECMWFReading, UK
Operational models: 10^7 – 10^8 variables
IMGI HPC workshop 2004
Outline
High-Resolution Numerical Modeling and Predictability of Atmospheric Flows
1. Atmospheric models
2. Stability of flows
specific error structures: singular vectors, data assimilation
3. Additional remarks
4. High-resolution modeling
• Past research: single-processor computing
• Current research: multi-processor parallel computing
• Introducing the numerical models
• Introducing the computing facilities
• An example: simulation of bora winds
• Outlook: numerical weather prediction for the Winter Universiade 2005
IMGI HPC workshop 2004
High-Resolution Numerical Modeling of Atmospheric Flows
flow over mountains
orographically induced precipitation
flow around mountains
flow through mountain gaps
Past Research – Single-processor computing (Origin XL, o2000)
Current Research – Multi-processor parallel computing (Origin o3800, ZID-CC)
High-Resolution Numerical Modeling of Atmospheric Flows
IMGI HPC workshop 2004
Numerical modeling with
realistic orography• case studies• weather prediction
Flow around the AlpsFlow over the Alps
boundary conditions
analysis or forecast
We are using two modelsGlobal Model (ECMWF*)
* European Centre for Medium-Range Weather Forecasts (Reading, UK)** Regional Atmospheric Modeling System (CSU, Ft. Collins, USA)
• spectral technique• single global domain• x 40 km (TL511)
High-Resolution Numerical Modeling of Atmospheric Flows
IMGI HPC workshop 2004
Limited Area Model (RAMS**)
• finite-difference technique• several nested domains, covering limited areas, centered near the location of interest• x 100 m – 1 km
Global Model @ ECMWF (UK)
IBM supercomputer2 clusters, each with 30 servers (p690), each server having 32 processors (1.3 GHz Power4)
Origin o3800 compute-server48 processors (600 MHz MIPS R14000)
RAMS @ ZID (IBK)
ZID-CC compute-cluster16 servers (Transtec), each with 2 processors (2.2 GHz Intel Xeon)
ftp
High-Resolution Numerical Modeling of Atmospheric Flows
IMGI HPC workshop 2004
RAMS model setup • 5 nested grids• x = 267 m to 65 km• 56 vertical levels• 6443024 grid points• 1440 master time steps for 1-day forecast
Parallel computing on ZID-CC cluster• 8 processors• master–slave configuration• domain decomposition technique
High-Resolution Numerical Modeling of Atmospheric Flows
IMGI HPC workshop 2004
An example: Simulation of bora winds to the lee of the Dinaric Alps
An example: Simulation of bora winds to the lee of the Dinaric Alps
Computing time for RAMS at ZID-CC cluster with 8 CPUs• ~180 seconds for a 60-second time step• 73.8 hours for a 24-hour simulation
number of time steps
elap
sed
seco
nds
}nodes
}master
Every time step:I/O communication
Every 20 minutes: update with radiative transfer model
Every hour: data I/O from/to hard disk by master node
High-Resolution Numerical Modeling of Atmospheric Flows
IMGI HPC workshop 2004
An example: Simulation of bora winds to the lee of the Dinaric Alps
High-Resolution Numerical Modeling of Atmospheric Flows
IMGI HPC workshop 2004
DLR Falcon backscatter lidar
observation
AdriaticSea
DinaricAlps
flow
simulation
bora
Outlook: Numerical Weather Prediction (NWP) @ IMGI/ZID
High-Resolution Numerical Modeling of Atmospheric Flows
IMGI HPC workshop 2004
Goal
• Set up RAMS as NWP model for the Innsbruck region
• Compute daily forecast on ZID-CC and/or Origin 3800
Benefit
Resolving various weather phenomena occurring in different
spatial scales: between the Alpine scale (L~100 km) and the
valley scale (L~1 km)