using high-performance computing to predict extreme weather
TRANSCRIPT
October 29, 2014
Using High-Performance
Computing to Predict Extreme
WeatherPeter Bauer
October 29, 2014October 29, 2014
Independent intergovernmental organisation
established in 1975
with19 Member States15 Co-operating States
European Centre for Medium-Range Weather Forecasts
October 29, 2014
The success story of Numerical Weather Prediction: Wind storms28-29 October 2013 ‘Christian’ wind gusts
5-day forecast of probabilities for wind gusts exceeding > 10m/s
October 29, 2014
The success story of Numerical Weather Prediction: Heat wavesMaximum observed temperature
Maximum forecast temperature day-3 – day-4
Temperature anomaly ensemble forecast week-2
… and week-3½
Week 2-3½ forecast of probabilities for temperature anomalies exceeding > 5-10K
October 29, 2014
29-09-15 30-09-15 01-10-15
Individual trajectories for JOAQUIN during the next 240 hourstracks: thick solid=HRES; thick dot=CTRL; thin solid=EPS members [coloured]
The success story of Numerical Weather Prediction: Hurricanes
October 29, 2014
Day 0
Day 2Southern Gaza Strip, on April18, 2012
Day 4
The success story of Numerical Weather Prediction: Dust storms
October 29, 2014
Previously on …?
John von Neumann (1903-1957), Mathematician:• Function theory, abstract algebra,
quantum physics• Leader of Electronic Computer Project
(1946-52)
Jule Charney (1917-1981), Meteorologist:• Set of equations for numerical prediction of planetary waves• Founder of theory of baroclinic instability
Electronic Numerical Integrator and Computer (ENIAC)• 140 kW, 30 tons, 18,000 thermo-ionic valves• 1-layer model, resolution 400-700 km, North American domain• Single 24-hour forecast needed 24 hours compute time
ENIAC 1950
The same prediction needed 1 second on a Nokia 6300 mobile phone (2006)!
Lewis Fry Richardson (1881-1953), Physicist, Meteorologist, Psychologist, Pacifist:• Basics of numerical weather prediction• First explicit calculation of weather on 20 May 1910
October 29, 2014
Computer power
Model complexity
Model resolution
Tomorrow
Today
Multiple dimensions
EnsemblesLong climate runs
October 29, 2014
What is the challenge?
Observations Models
Volume 20 million = 2 x 107 5 million grid points100 levels10 prognostic variables = 5 x 109
Type 98% from 60 different satellite instruments
physical parameters of atmosphere, waves, ocean
Observations Models
Volume 200 million = 2 x 108 500 million grid points200 levels100 prognostic variables = 1 x 1013
Type 98% from 80 different satellite instruments
physical and chemical parameters of atmosphere, waves, ocean, ice, vegetation
Today:
Tomorrow:
Factor 10 Factor 2000per day per time step
(10-day forecast = 1440 time steps)
October 29, 2014
scalability range
scalability range
Ensemble
Single
Simple compute projection (only resolution)
2015 2025
M€ electricity/year
Power limit
[Bauer et al. 2015]
October 29, 2014
2015 Time critical• 21 TB/day written• 22 million fields• 85 million products• 11 TB/day sent to customers
Non-time critical• 100 TB/day archived• 400 research experiments• 400,000 jobs / day
20202025?
Time critical• 128 TB/day written• 90 million fields• 450 million products• 60 TB/day sent to customers
Non-time critical• 1 PB/day archived• 1,000 research experiments• 1,000,000 jobs / day
Data projection
Factor 5-10 every 5 years!
time
October 29, 2014
[Schulthess 2015]
Traditional science workflow
October 29, 2014
[Schulthess 2015]
Future science workflow
science specific code generic code
Energy efficient SCalable Algorithms for weather Prediction at Exascale www.hpc-escape.eu
October 29, 2014October 29, 2014
‘The quiet revolution of numerical weather prediction’ by P. Bauer, A.J. Thorpe, G. Brunet
in Nature, 3 September 2015:
The future of Numerical Weather Prediction
[IPCC]