Pushing the Computational Limits of Climate Simulation

Abstract. High-resolution earth system model simulations generate enormous data volumes, and retaining the data from these simulations often strains institutional storage resources. Further, these exceedingly large storage requirements negatively impact science objectives by forcing reductions in data output frequency, simulation length, or ensemble size, for example. To lessen data volumes from the Community Earth System Model (CESM), we advocate the use of lossy data compression techniques. While lossy data compression does not exactly preserve the original data (as lossless compression does), lossy techniques have an advantage in terms of smaller storage requirements. To preserve the integrity of the scientific simulation data, the effects of lossy data compression on the original data should, at a minimum, not be statistically distinguishable from the natural variability of the climate system, and previous preliminary work with data from CESM has shown this goal to be attainable. However, to ultimately convince climate scientists that it is acceptable to use lossy data compression, we provide climate scientists with access to publicly available climate data that has undergone lossy data compression. In particular, we report on the results of a lossy data compression experiment with output from the CESM Large Ensemble (CESM-LE) Community Project, in which we challenge climate scientists to examine features of the data relevant to their interests, and attempt to identify which of the ensemble members have been compressed and reconstructed. We find that while detecting distinguishing features is certainly possible, the compression effects noticeable in these features are often unimportant or disappear in post-processing analyses. In addition, we perform several analyses that directly compare the original data to the reconstructed data to investigate the preservation, or lack thereof, of specific features critical to climate science. Overall, we conclude that applying lossy data compression to climate simulation data is both advantageous in terms of data reduction and generally acceptable in terms of effects on scientific results.

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Evaluating lossy data compression on climate simulation data within a large ensemble

Geoscientific Model Development ◽

10.5194/gmd-9-4381-2016 ◽

2016 ◽

Vol 9 (12) ◽

pp. 4381-4403 ◽

Cited By ~ 24

Author(s):

Allison H. Baker ◽

Dorit M. Hammerling ◽

Sheri A. Mickelson ◽

Haiying Xu ◽

Martin B. Stolpe ◽

...

Keyword(s):

Data Compression ◽

Climate Science ◽

Original Data ◽

Earth System Model ◽

System Model ◽

Climate Simulation ◽

Earth System ◽

Climate Data ◽

Large Ensemble ◽

Simulation Data

Abstract. High-resolution Earth system model simulations generate enormous data volumes, and retaining the data from these simulations often strains institutional storage resources. Further, these exceedingly large storage requirements negatively impact science objectives, for example, by forcing reductions in data output frequency, simulation length, or ensemble size. To lessen data volumes from the Community Earth System Model (CESM), we advocate the use of lossy data compression techniques. While lossy data compression does not exactly preserve the original data (as lossless compression does), lossy techniques have an advantage in terms of smaller storage requirements. To preserve the integrity of the scientific simulation data, the effects of lossy data compression on the original data should, at a minimum, not be statistically distinguishable from the natural variability of the climate system, and previous preliminary work with data from CESM has shown this goal to be attainable. However, to ultimately convince climate scientists that it is acceptable to use lossy data compression, we provide climate scientists with access to publicly available climate data that have undergone lossy data compression. In particular, we report on the results of a lossy data compression experiment with output from the CESM Large Ensemble (CESM-LE) Community Project, in which we challenge climate scientists to examine features of the data relevant to their interests, and attempt to identify which of the ensemble members have been compressed and reconstructed. We find that while detecting distinguishing features is certainly possible, the compression effects noticeable in these features are often unimportant or disappear in post-processing analyses. In addition, we perform several analyses that directly compare the original data to the reconstructed data to investigate the preservation, or lack thereof, of specific features critical to climate science. Overall, we conclude that applying lossy data compression to climate simulation data is both advantageous in terms of data reduction and generally acceptable in terms of effects on scientific results.

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Development and evaluation of CNRM Earth system model – CNRM-ESM1

Geoscientific Model Development ◽

10.5194/gmd-9-1423-2016 ◽

2016 ◽

Vol 9 (4) ◽

pp. 1423-1453 ◽

Cited By ~ 21

Author(s):

Roland Séférian ◽

Christine Delire ◽

Bertrand Decharme ◽

Aurore Voldoire ◽

David Salas y Melia ◽

...

Keyword(s):

Carbon Cycle ◽

Sea Ice ◽

Ecosystem Respiration ◽

World Ocean ◽

Earth System Model ◽

System Model ◽

Shortwave Radiation ◽

Climate Simulation ◽

Co2 Uptake ◽

Earth System

Abstract. We document the first version of the Centre National de Recherches Météorologiques Earth system model (CNRM-ESM1). This model is based on the physical core of the CNRM climate model version 5 (CNRM-CM5) model and employs the Interactions between Soil, Biosphere and Atmosphere (ISBA) and the Pelagic Interaction Scheme for Carbon and Ecosystem Studies (PISCES) as terrestrial and oceanic components of the global carbon cycle. We describe a preindustrial and 20th century climate simulation following the CMIP5 protocol. We detail how the various carbon reservoirs were initialized and analyze the behavior of the carbon cycle and its prominent physical drivers. Over the 1986–2005 period, CNRM-ESM1 reproduces satisfactorily several aspects of the modern carbon cycle. On land, the model captures the carbon cycling through vegetation and soil, resulting in a net terrestrial carbon sink of 2.2 Pg C year−1. In the ocean, the large-scale distribution of hydrodynamical and biogeochemical tracers agrees with a modern climatology from the World Ocean Atlas. The combination of biological and physical processes induces a net CO2 uptake of 1.7 Pg C year−1 that falls within the range of recent estimates. Our analysis shows that the atmospheric climate of CNRM-ESM1 compares well with that of CNRM-CM5. Biases in precipitation and shortwave radiation over the tropics generate errors in gross primary productivity and ecosystem respiration. Compared to CNRM-CM5, the revised ocean–sea ice coupling has modified the sea-ice cover and ocean ventilation, unrealistically strengthening the flow of North Atlantic deep water (26.1 ± 2 Sv). It results in an accumulation of anthropogenic carbon in the deep ocean.

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Development and evaluation of CNRM Earth-System model – CNRM-ESM1

Geoscientific Model Development Discussions ◽

10.5194/gmdd-8-5671-2015 ◽

2015 ◽

Vol 8 (7) ◽

pp. 5671-5739

Author(s):

R. Séférian ◽

C. Delire ◽

B. Decharme ◽

A. Voldoire ◽

D. Salas y Melia ◽

...

Keyword(s):

Carbon Cycle ◽

Sea Ice ◽

Ecosystem Respiration ◽

World Ocean ◽

Earth System Model ◽

System Model ◽

Shortwave Radiation ◽

Climate Simulation ◽

Co2 Uptake ◽

Earth System

Abstract. We introduce and document the first version of the Centre National de Recherches Météorologiques Earth system model (CNRM-ESM1). This model is based on the physical core of the CNRM-CM5 model and employs the Interactions between Soil, Biosphere and Atmosphere (ISBA) module and the Pelagic Interaction Scheme for Carbon and Ecosystem Studies (PISCES) as terrestrial and oceanic components of the global carbon cycle. We describe a preindustrial and 20th century climate simulation following the CMIP5 protocol. We detail how the various carbon reservoirs were initialized and analyze the behavior of the carbon cycle and its prominent physical drivers. CNRM-ESM1 reproduces satisfactorily several aspects of the modern carbon cycle. On land, the model reasonably captures the carbon cycling through vegetation and soil, resulting in a net terrestrial carbon sink of 2.2 Pg C y-1. In the ocean, the large-scale distribution of hydrodynamical and biogeochemical tracers agrees well with a modern climatology from the World Ocean Atlas. The combination of biological and physical processes induces a net CO2 uptake of 1.7 Pg C y-1 that falls within the range of recent estimates. Our analysis shows that the atmospheric climate of CNRM-ESM1 compares well with that of CNRM-CM5. Biases in precipitation and shortwave radiation over the Tropics generate errors in gross primary productivity and ecosystem respiration. Compared to CNRM-CM5, the revised ocean–sea ice coupling has modified the sea-ice cover and ocean ventilation, unrealistically strengthening the flow of North Atlantic deep water (26.1 ± 2 Sv). It results in an accumulation of anthropogenic carbon in the deep ocean.

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A new synoptic scale resolving global climate simulation using the Community Earth System Model

Journal of Advances in Modeling Earth Systems ◽

10.1002/2014ms000363 ◽

2014 ◽

Vol 6 (4) ◽

pp. 1065-1094 ◽

Cited By ~ 130

Author(s):

R. Justin Small ◽

Julio Bacmeister ◽

David Bailey ◽

Allison Baker ◽

Stuart Bishop ◽

...

Keyword(s):

Global Climate ◽

Earth System Model ◽

System Model ◽

Climate Simulation ◽

Earth System ◽

Synoptic Scale ◽

Community Earth System Model

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The Australian Earth System Model: ACCESS-ESM1.5

Journal of Southern Hemisphere Earth System Science ◽

10.1071/es19035 ◽

2020 ◽

Cited By ~ 4

Author(s):

Tilo Ziehn ◽

Matthew A. Chamberlain ◽

Rachel M. Law ◽

Andrew Lenton ◽

Roger W. Bodman ◽

...

Keyword(s):

Carbon Cycle ◽

Coupled Model ◽

Earth System Model ◽

System Model ◽

Climate Simulation ◽

Earth System ◽

Historical Simulation ◽

Modes Of Variability ◽

Australian Community ◽

Ocean Carbon

The Australian Community Climate and Earth System Simulator (ACCESS) has been extended to include land and ocean carbon cycle components to form an Earth System Model (ESM). The current version, ACCESS-ESM1.5, has been mainly developed to enable Australia to participate in the Coupled Model Intercomparison Project Phase 6 (CMIP6) with an ESM version. Here we describe the model components and changes to the previous version, ACCESS-ESM1. We use the 500-year pre-industrial control run to highlight the stability of the physical climate and the carbon cycle. The long spin-up, negligible drift in temperature and small pre-industrial net carbon fluxes (0.02 and 0.08 PgC year−1 for land and ocean respectively) highlight the suitability of ACCESS-ESM1.5 to explore modes of variability in the climate system and coupling to the carbon cycle. The physical climate and carbon cycle for the present day have been evaluated using the CMIP6 historical simulation by comparing against observations and ACCESS-ESM1. Although there is generally little change in the climate simulation from the earlier model, many aspects of the carbon simulation are improved. An assessment of the climate response to CO2 forcing indicates that ACCESS-ESM1.5 has an equilibrium climate sensitivity of 3.87°C.

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Transient climate simulation of Last Millennium using integrated Earth System Model

Quaternary International ◽

10.1016/j.quaint.2012.08.1600 ◽

2012 ◽

Vol 279-280 ◽

pp. 475

Author(s):

Tetsuo Sueyosh

Keyword(s):

Earth System Model ◽

System Model ◽

Climate Simulation ◽

Last Millennium ◽

Earth System

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A new ensemble-based consistency test for the Community Earth System Model (pyCECT v1.0)

Geoscientific Model Development ◽

10.5194/gmd-8-2829-2015 ◽

2015 ◽

Vol 8 (9) ◽

pp. 2829-2840 ◽

Cited By ~ 23

Author(s):

A. H. Baker ◽

D. M. Hammerling ◽

M. N. Levy ◽

H. Xu ◽

J. M. Dennis ◽

...

Keyword(s):

Software Verification ◽

Earth System Model ◽

System Model ◽

Climate Simulation ◽

Earth System ◽

Consistency Test ◽

Community Earth System Model ◽

Software And Hardware ◽

Verification Process

Abstract. Climate simulation codes, such as the Community Earth System Model (CESM), are especially complex and continually evolving. Their ongoing state of development requires frequent software verification in the form of quality assurance to both preserve the quality of the code and instill model confidence. To formalize and simplify this previously subjective and computationally expensive aspect of the verification process, we have developed a new tool for evaluating climate consistency. Because an ensemble of simulations allows us to gauge the natural variability of the model's climate, our new tool uses an ensemble approach for consistency testing. In particular, an ensemble of CESM climate runs is created, from which we obtain a statistical distribution that can be used to determine whether a new climate run is statistically distinguishable from the original ensemble. The CESM ensemble consistency test, referred to as CESM-ECT, is objective in nature and accessible to CESM developers and users. The tool has proven its utility in detecting errors in software and hardware environments and providing rapid feedback to model developers.

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