1
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
2
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
Institute for Meteorology and Climate Research (IMK)
Fundamental research on climate, water cycle and trace
substances
Turbulence, Convection, Cloud formation, Aerosol physics,
Precipitation formation, Exchange processes on Earth’s
surface
Aerosols, Trace Gases and Climate Processes
(head of group: B. Vogel)
Representation of aerosols and gas phase chemistry on
the regional scale (model system COSMO-ART)
Particular interest on the interaction of aerosols and clouds
in the atmospheric system
3
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
COSMO–ART
(ART = Aerosols and Reactive Trace Gases)
Ext. Parameters
Vogel et al., 2009, ACP
4
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
= operational weather forecast model (DWD)
Feedback processes realized in COSMO-ART
Aerosol
Radiation
Gas phase
Dynamics
Temperature
Aerosol cloud interaction
5
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
Humidity
Precipitation
Clouds
Future Applications:
Decadal forecasts of the regional climate of Europe
Interaction of natural and anthropogenic aerosols with climate
Model runs with CCLM-ART (= climate version of COSMO-ART)
Computational demand:
Based on AIX (16 processors) without speed-up of COSMO-ART:
10 year model run = 112 CPU years
10-20 scenario runs
Transported 3-D variables ~60 (gases) + ~ 80 (aerosols)
250x250x40 gridpoints
(future applications due to increased resolution ~factor 4)
6
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
Profiling test case
Run of 24 h initialized at 22nd June 2007 at 00:00 UTC
193x113x40 grid points, dt=40s, resolution of 0.25°
Machine: IBM AIX cluster at KIT
2 nodes with 8 cores each
Profiling done with Scalasca
7
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
Total run time: 268.4 CPU hours (2 nodes x 8 cores)
cradm2 (31,48%)
ISOROPIA (14,72%)
ART org (22,72%)
8
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
Further Metrics
Metric
Value
ART
Computational
Imbalance
17,33 CPU hours
(6,46 % of total)
85% of imbalance due to ART
Synchronizations
56,63 CPU hours
(21,10 % of total)
47 % ART (anth. Emissions)
52 % organize_data (data output)
Communciations
9,75e7
89 % in dynamics and leapfrog
Bytes transferred
5,75e12 B
94 % in dynamics and leapfrog
Important imbalance of the code
Large need of communications due to more
than 150 additional 3D prognotstic fields
9
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
Way forward
Model chemistry and physics:
Use KPP chemical solver (GPU “version”)
Use a simplified version of ISOROPIA
Call chemistry and aerosols not at every time-step
Try to reduce waiting time for anthropogenic emissions ( call only every 6 hours)
Numerics:
Code is partly vectorized -> Compiler options for non-vectorized code
Lump messages together, to reduce number of communications
(but increase their size)
Optimize utility routines (unit conversion, string comparision)
10
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
11
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
12
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
14
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
Parallel Visualization
parallel visualization
of output data
Visualization
-Cluster
Data-Server
convert *.grb into *.vts
generate animated gif
out of visualized states
HPC-system
Desktop-PC
analyze forecast
17
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
Visualization Temperature+Rain
18
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
19
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
20
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale
21
The Interactions of Aerosols, Clouds, and Radiation on the Regional Scale