Marko Stanković, Siniša Ivković (ETF)

Radomir Radojičić, Luka Ilić (Meteos)

The Source-Sink Model:A DataFlow Implementation

(work in progress)

University of BelgradeSchool of Electrical Engineering (ETF)

A project co-funded by Serbian Government and SMEs

2/8

Contents

• Eta model

• Source-sink model

• Method of implementation

• Results so far

• Next Steps

3/8

The Eta Model

• State-of-the-art atmospheric model

• Developed in the ’70s in the ex-YU

• η (eta) – the vertical coordinate

• ηs = (pref(zs)-pt) / (pr(z=0)−pt)

• Horizontal coordinates: Arakawa E-grid

• Preventing pressure-gradient force errors due to steep topography

4/8

The Source-Sink Model

• Shallow-water equations model

• Defined on Arakawa E-grid

• Process of geostrophic adjustment

• Four main components:1. Continuity equation (Mesinger, Janjić)

2. Updating the height

3. Equation of motion

4. Updating the speed

5/8

Method of Implementation

• Move all the calculation to the DFE

• All data stored on DFE

• Initial iteration is streamed from host

• Its results go to RAM on card

• Iterations are done locally

• Final iteration’s results streamed to host

6/8

Results so Far

• Loop calculating four variables

• Same execution time on host and DFE

• After implementing more code– Expected DFE exec time: Almost constant– Expected host exec time: Rises linearly

More code -> More speed-up!

7/8

Next Steps (due: March 31, 2013)

• Finishing the implementation

• Performing the final measurements

Future Work:

• Arbitrary number of sources and sinks

8/8

Thank you!

Questions?

Marko Stanković (stankovic.marko@gmail.com)Siniša Ivković (sinisa.ivkovic@gmail.com)

Radomir Radojičić (rrbata@meteos.rs)Luka Ilić (luka.ilic@sewa-weather.com)