scholarly journals Multi-objective optimization of GENIE Earth system models

2009 ◽  
Vol 367 (1898) ◽  
pp. 2623-2633 ◽  
Author(s):  
Andrew R. Price ◽  
Richard J. Myerscough ◽  
Ivan I. Voutchkov ◽  
Robert Marsh ◽  
Simon J. Cox
Keyword(s):  
High Performance ◽  
Climate Models ◽  
Earth System ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Surface Models ◽  
Iterative Evaluation ◽  
Performance Computing ◽  
Earth System Models

The tuning of parameters in climate models is essential to provide reliable long-term forecasts of Earth system behaviour. We apply a multi-objective optimization algorithm to the problem of parameter estimation in climate models. This optimization process involves the iterative evaluation of response surface models (RSMs), followed by the execution of multiple Earth system simulations. These computations require an infrastructure that provides high-performance computing for building and searching the RSMs and high-throughput computing for the concurrent evaluation of a large number of models. Grid computing technology is therefore essential to make this algorithm practical for members of the GENIE project.

scholarly journals Climate feedbacks in the Earth system and prospects for their evaluation

2018 ◽  
Author(s):  
Christoph Heinze ◽  
Veronika Eyring ◽  
Pierre Friedlingstein ◽  
Colin Jones ◽  
Yves Balkanski ◽  
...  
Keyword(s):  
Climate Models ◽  
Climate Projections ◽  
Earth System ◽  
Climate Feedbacks ◽  
Comprehensive Overview ◽  
The Earth ◽  
Cloud Dynamics ◽  
Spatial And Temporal Heterogeneity ◽  
Earth System Models

Abstract. Earth system models (ESMs) are key tools for providing climate projections under different scenarios of human-induced forcing. ESMs include a large number of additional processes and feedbacks such as biogeochemical cycles that traditional physical climate models do not consider. Yet, some processes such as cloud dynamics and ecosystem functional response still have fairly high uncertainties. In this article, we present an overview of climate feedbacks for Earth system components currently included in state-of-the-art ESMs and discuss the challenges to evaluate and quantify them. Uncertainties in feedback quantification arise from the interdependencies of biogeochemical matter fluxes and physical properties, the spatial and temporal heterogeneity of processes, and the lack of long-term continuous observational data to constrain them. We present an outlook for promising approaches that can help quantifying and constraining the large number of feedbacks in ESMs in the future. The target group for this article includes generalists with a background in natural sciences and an interest in climate change as well as experts working in interdisciplinary climate research (researchers, lecturers, and students). This study updates and significantly expands upon the last comprehensive overview of climate feedbacks in ESMs, which was produced 15 years ago (NRC, 2003).

scholarly journals Replicability of the EC-Earth3 Earth System Model under a change in computing environment

2019 ◽  
Author(s):  
François Massonnet ◽  
Martin Ménégoz ◽  
Mario Acosta ◽  
Xavier Yepes-Arbós ◽  
Eleftheria Exarchou ◽  
...  
Keyword(s):  
High Performance ◽  
Standard Test ◽  
Earth System ◽  
Computing Environment ◽  
Climate Simulations ◽  
Alternative Solutions ◽  
Default Assumption ◽  
Performance Computing ◽  
Recent Version ◽  
Earth System Models

Abstract. Most Earth System Models (ESMs) are running under different high-performance computing (HPC) environments. This has several advantages, from allowing different groups to work with the same tool in parallel to leveraging the burden of ensemble climate simulations but also offering alternative solutions in case of shutdown (expected or not) of any of the environments. However, for obvious scientific reasons, it is critical to ensure that ESMs provide identical results under changes in computing environment. While strict bit-for-bit reproducibility is not always guaranteed with ESMs, it is desirable that results obtained under one computing environment are at least statistically indistinguishable from those obtained under another environment, which we term a replicability condition following the metrology nomenclature. Here, we develop a protocol to assess the replicability of the EC-Earth ESM. Using two versions of EC-Earth, we present one case of non-replicability and one case of replicability. The non-replicable case occurs with the older version of the model and likely finds its origin in the treatment of river runoffs along Antarctic coasts. By contrast, the more recent version of the model provides replicable results. The methodology presented here has been adopted as a standard test by the EC-Earth consortium (27 institutions in Europe) to evaluate the replicability of any new model version across platforms, including for CMIP6 experiments. To a larger extent, it can be used to assess whether other ESMs can safely be ported from one HPC environment to another for studying climate-related questions. Our results and experience with this work suggest that the default assumption should be that ESMs are not replicable under changes in the HPC environment, until proven otherwise.

scholarly journals ESD Reviews: Climate feedbacks in the Earth system and prospects for their evaluation

2019 ◽  
Vol 10 (3) ◽  
pp. 379-452 ◽  
Author(s):  
Christoph Heinze ◽  
Veronika Eyring ◽  
Pierre Friedlingstein ◽  
Colin Jones ◽  
Yves Balkanski ◽  
...  
Keyword(s):  
Climate Models ◽  
Climate Projections ◽  
Earth System ◽  
Climate Feedbacks ◽  
Comprehensive Overview ◽  
The Earth ◽  
Cloud Dynamics ◽  
Spatial And Temporal Heterogeneity ◽  
Earth System Models

Abstract. Earth system models (ESMs) are key tools for providing climate projections under different scenarios of human-induced forcing. ESMs include a large number of additional processes and feedbacks such as biogeochemical cycles that traditional physical climate models do not consider. Yet, some processes such as cloud dynamics and ecosystem functional response still have fairly high uncertainties. In this article, we present an overview of climate feedbacks for Earth system components currently included in state-of-the-art ESMs and discuss the challenges to evaluate and quantify them. Uncertainties in feedback quantification arise from the interdependencies of biogeochemical matter fluxes and physical properties, the spatial and temporal heterogeneity of processes, and the lack of long-term continuous observational data to constrain them. We present an outlook for promising approaches that can help to quantify and to constrain the large number of feedbacks in ESMs in the future. The target group for this article includes generalists with a background in natural sciences and an interest in climate change as well as experts working in interdisciplinary climate research (researchers, lecturers, and students). This study updates and significantly expands upon the last comprehensive overview of climate feedbacks in ESMs, which was produced 15 years ago (NRC, 2003).

scholarly journals Replicability of the EC-Earth3 Earth system model under a change in computing environment

2020 ◽  
Vol 13 (3) ◽  
pp. 1165-1178 ◽  
Author(s):  
François Massonnet ◽  
Martin Ménégoz ◽  
Mario Acosta ◽  
Xavier Yepes-Arbós ◽  
Eleftheria Exarchou ◽  
...  
Keyword(s):  
High Performance ◽  
Standard Test ◽  
Earth System ◽  
Computing Environment ◽  
Climate Simulations ◽  
Alternative Solutions ◽  
Default Assumption ◽  
Performance Computing ◽  
Recent Version ◽  
Earth System Models

Abstract. Most Earth system models (ESMs) are running under different high-performance computing (HPC) environments. This has several advantages, from allowing different groups to work with the same tool in parallel to leveraging the burden of ensemble climate simulations, but it also offers alternative solutions in the case of shutdown (expected or not) of any of the environments. However, for obvious scientific reasons, it is critical to ensure that ESMs provide identical results under changes in computing environment. While strict bit-for-bit reproducibility is not always guaranteed with ESMs, it is desirable that results obtained under one computing environment are at least statistically indistinguishable from those obtained under another environment, which we term a “replicability” condition following the metrology nomenclature. Here, we develop a protocol to assess the replicability of the EC-Earth ESM. Using two versions of EC-Earth, we present one case of non-replicability and one case of replicability. The non-replicable case occurs with the older version of the model and likely finds its origin in the treatment of river runoff along Antarctic coasts. By contrast, the more recent version of the model provides replicable results. The methodology presented here has been adopted as a standard test by the EC-Earth consortium (27 institutions in Europe) to evaluate the replicability of any new model version across platforms, including for CMIP6 experiments. To a larger extent, it can be used to assess whether other ESMs can safely be ported from one HPC environment to another for studying climate-related questions. Our results and experience with this work suggest that the default assumption should be that ESMs are not replicable under changes in the HPC environment, until proven otherwise.

scholarly journals The computational future for climate and Earth system models: on the path to petaflop and beyond

2008 ◽  
Vol 367 (1890) ◽  
pp. 833-846 ◽  
Author(s):  
Warren M Washington ◽  
Lawrence Buja ◽  
Anthony Craig
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Ecological Model ◽  
Earth System ◽  
System Models ◽  
Model Components ◽  
Supercomputer Systems ◽  
Physical And Chemical ◽  
Earth System Models

The development of the climate and Earth system models has had a long history, starting with the building of individual atmospheric, ocean, sea ice, land vegetation, biogeochemical, glacial and ecological model components. The early researchers were much aware of the long-term goal of building the Earth system models that would go beyond what is usually included in the climate models by adding interactive biogeochemical interactions. In the early days, the progress was limited by computer capability, as well as by our knowledge of the physical and chemical processes. Over the last few decades, there has been much improved knowledge, better observations for validation and more powerful supercomputer systems that are increasingly meeting the new challenges of comprehensive models. Some of the climate model history will be presented, along with some of the successes and difficulties encountered with present-day supercomputer systems.

scholarly journals Correction: A multi-objective optimization-based layer-by-layer blade-coating approach for organic solar cells: rational control of vertical stratification for high performance

2020 ◽  
Vol 13 (1) ◽  
pp. 317-317
Author(s):  
Rui Sun ◽  
Jie Guo ◽  
Qiang Wu ◽  
Zhuohan Zhang ◽  
Wenyan Yang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
High Performance ◽  
Vertical Stratification ◽  
Layer By Layer ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Rational Control ◽  
Blade Coating ◽  
Energy Environ

Correction for ‘A multi-objective optimization-based layer-by-layer blade-coating approach for organic solar cells: rational control of vertical stratification for high performance’ by Rui Sun et al., Energy Environ. Sci., 2019, 12, 3118–3132.

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