Towards European-scale convection-resolving climate simulations with GPUs: a study with COSMO 4.19
The representation of moist convection in climate models represents a major challenge, due to the small scales involved. Using horizontal grid spacings of <i>O</i>(1km), convection-resolving weather and climate models allows one to explicitly resolve deep convection. However, due to thei...
Main Authors: | , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2016-09-01
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Series: | Geoscientific Model Development |
Online Access: | http://www.geosci-model-dev.net/9/3393/2016/gmd-9-3393-2016.pdf |
Summary: | The representation of moist convection in climate models represents a major
challenge, due to the small scales involved. Using horizontal grid spacings
of <i>O</i>(1km), convection-resolving weather and climate models allows
one to explicitly resolve deep convection. However, due to their extremely
demanding computational requirements, they have so far been limited to short
simulations and/or small computational domains. Innovations in supercomputing
have led to new hybrid node designs, mixing conventional multi-core hardware
and accelerators such as graphics processing units (GPUs). One of the first
atmospheric models that has been fully ported to these architectures is the
COSMO (Consortium for Small-scale Modeling) model.<br><br>Here we present the convection-resolving COSMO model on continental scales
using a version of the model capable of using GPU accelerators. The
verification of a week-long simulation containing winter storm Kyrill shows
that, for this case, convection-parameterizing simulations and
convection-resolving simulations agree well. Furthermore, we demonstrate the
applicability of the approach to longer simulations by conducting a
3-month-long simulation of the summer season 2006. Its results
corroborate the findings found on smaller domains such as more credible
representation of the diurnal cycle of precipitation in convection-resolving
models and a tendency to produce more intensive hourly precipitation events.
Both simulations also show how the approach allows for the representation of
interactions between synoptic-scale and meso-scale atmospheric circulations
at scales ranging from 1000 to 10 km. This includes the formation of sharp
cold frontal structures, convection embedded in fronts and small eddies, or
the formation and organization of propagating cold pools. Finally, we assess
the performance gain from using heterogeneous hardware equipped with GPUs
relative to multi-core hardware. With the COSMO model, we now use a weather
and climate model that has all the necessary modules required for real-case
convection-resolving regional climate simulations on GPUs. |
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ISSN: | 1991-959X 1991-9603 |