scholarly journals Ocean biogeochemistry in the Norwegian Earth System Model version 2 (NorESM2)

2020 ◽  
Author(s):  
Jerry F. Tjiputra ◽  
Jörg Schwinger ◽  
Mats Bentsen ◽  
Anne L. Morée ◽  
Shuang Gao ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Dimethyl Sulfide ◽  
Carbon Dioxide Concentration ◽  
Coupled Model ◽  
Earth System Model ◽  
System Model ◽  
Historical Period ◽  
Co2 Fluxes ◽  
Earth System ◽  
Radiative Balance

Abstract. The ocean carbon cycle is a key player in the climate system through its role in regulating atmospheric carbon dioxide concentration as well as other processes that alter the Earth's radiative balance. In the second version of the Norwegian Earth System Model (NorESM2), the oceanic carbon cycle component has gone through numerous updates that include, amongst others, improved process representations, increased interactions with the atmosphere, and additional new tracers. Oceanic dimethyl sulfide (DMS) is now prognostically simulated and its fluxes are directly coupled with the atmospheric component, allowing for a direct feedback to the climate. Atmospheric nitrogen deposition and additional external inputs of other biogeochemical tracers through riverine are recently included in the model. The implementation of new tracers such as 'preformed' and 'natural' tracers enables a separation of physical from biogeochemical drivers as well as of internal from external forcings and hence a better diagnostic of the simulated biogeochemical variability. Carbon isotope tracers have been implemented and will be relevant for studying long-term past climate changes. Here, we describe these new model implementations and present the evaluation of the model's performance in simulating the observed climatological states of water column biogeochemistry as well as in simulating the transient evolution over the historical period. Compared to its predecessor NorESM1, the new model's performance has improved considerably in many aspects. In the interior, the observed spatial patterns of nutrients, oxygen, and carbon chemistry are better reproduced, reducing the overall model biases. A new set of ecosystem parameters and improved mixed layer dynamics improves the representation of upper ocean processes (biological production and air-sea CO2 fluxes) at seasonal time scale. Transient warming and air-sea CO2 fluxes over the historical period are also in good agreement with observation-based estimates. NorESM2 participates in the Coupled Model Intercomparison Project phase 6 (CMIP6) through DECK (Diagnostic, Evaluation and Characterization of Klima) and several endorsed MIP-simulations.

scholarly journals Ocean biogeochemistry in the Norwegian Earth System Model version 2 (NorESM2)

2020 ◽  
Vol 13 (5) ◽  
pp. 2393-2431 ◽  
Author(s):  
Jerry F. Tjiputra ◽  
Jörg Schwinger ◽  
Mats Bentsen ◽  
Anne L. Morée ◽  
Shuang Gao ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Dimethyl Sulfide ◽  
Carbon Dioxide Concentration ◽  
Coupled Model ◽  
Earth System Model ◽  
System Model ◽  
Historical Period ◽  
Co2 Fluxes ◽  
Earth System ◽  
Radiative Balance

Abstract. The ocean carbon cycle is a key player in the climate system through its role in regulating the atmospheric carbon dioxide concentration and other processes that alter the Earth's radiative balance. In the second version of the Norwegian Earth System Model (NorESM2), the oceanic carbon cycle component has gone through numerous updates that include, amongst others, improved process representations, increased interactions with the atmosphere, and additional new tracers. Oceanic dimethyl sulfide (DMS) is now prognostically simulated and its fluxes are directly coupled with the atmospheric component, leading to a direct feedback to the climate. Atmospheric nitrogen deposition and additional riverine inputs of other biogeochemical tracers have recently been included in the model. The implementation of new tracers such as “preformed” and “natural” tracers enables a separation of physical from biogeochemical drivers as well as of internal from external forcings and hence a better diagnostic of the simulated biogeochemical variability. Carbon isotope tracers have been implemented and will be relevant for studying long-term past climate changes. Here, we describe these new model implementations and present an evaluation of the model's performance in simulating the observed climatological states of water-column biogeochemistry and in simulating transient evolution over the historical period. Compared to its predecessor NorESM1, the new model's performance has improved considerably in many aspects. In the interior, the observed spatial patterns of nutrients, oxygen, and carbon chemistry are better reproduced, reducing the overall model biases. A new set of ecosystem parameters and improved mixed layer dynamics improve the representation of upper-ocean processes (biological production and air–sea CO2 fluxes) at seasonal timescale. Transient warming and air–sea CO2 fluxes over the historical period are also in good agreement with observation-based estimates. NorESM2 participates in the Coupled Model Intercomparison Project phase 6 (CMIP6) through DECK (Diagnostic, Evaluation and Characterization of Klima) and several endorsed MIP simulations.

scholarly journals Description and evaluation of NorESM1-F: A fast version of the Norwegian Earth System Model (NorESM)

2018 ◽  
Author(s):  
Chuncheng Guo ◽  
Mats Bentsen ◽  
Ingo Bethke ◽  
Mehmet Ilicak ◽  
Jerry Tjiputra ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Sea Ice ◽  
Large Scale ◽  
Coupled Model ◽  
Coupled System ◽  
Internal Variability ◽  
Earth System Model ◽  
Meridional Overturning Circulation ◽  
System Model ◽  
Earth System

Abstract. A new computationally efficient version of the Norwegian Earth System Model (NorESM) is presented. This new version (here termed NorESM1-F) runs about 2.5 times faster (e.g. 90 model years per day on current hardware) than the version that contributed to the fifth phase of the Coupled Model Intercomparison project (CMIP5), i.e., NorESM1-M, and is therefore particularly suitable for multi-millennial paleoclimate and carbon cycle simulations or large ensemble simulations. The speedup is primarily a result of using a prescribed atmosphere aerosol chemistry and a tripolar ocean-sea ice horizontal grid configuration that allows an increase of the ocean-sea ice component time steps. Ocean biogeochemistry can be activated for fully coupled and semi-coupled carbon cycle applications. This paper describes the model and evaluates its performance using observations and NorESM1-M as benchmarks. The evaluation emphasises model stability, important large-scale features in the ocean and sea ice components, internal variability in the coupled system, and climate sensitivity. Simulation results from NorESM1-F in general agree well with observational estimates, and show evident improvements over NorESM1-M, for example, in the strength of the meridional overturning circulation and sea ice simulation, both important metrics in simulating past and future climates. Whereas NorESM1-M showed a slight global cool bias in the upper oceans, NorESM1-F exhibits a global warm bias. In general, however, NorESM1-F has more similarities than dissimilarities compared to NorESM1-M, and some biases and deficiencies known in NorESM1-M remain.

scholarly journals Description and evaluation of NorESM1-F: a fast version of the Norwegian Earth System Model (NorESM)

2019 ◽  
Vol 12 (1) ◽  
pp. 343-362 ◽  
Author(s):  
Chuncheng Guo ◽  
Mats Bentsen ◽  
Ingo Bethke ◽  
Mehmet Ilicak ◽  
Jerry Tjiputra ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Sea Ice ◽  
Large Scale ◽  
Coupled Model ◽  
Coupled System ◽  
Internal Variability ◽  
Earth System Model ◽  
Meridional Overturning Circulation ◽  
System Model ◽  
Earth System

Abstract. A new computationally efficient version of the Norwegian Earth System Model (NorESM) is presented. This new version (here termed NorESM1-F) runs about 2.5 times faster (e.g., 90 model years per day on current hardware) than the version that contributed to the fifth phase of the Coupled Model Intercomparison project (CMIP5), i.e., NorESM1-M, and is therefore particularly suitable for multimillennial paleoclimate and carbon cycle simulations or large ensemble simulations. The speed-up is primarily a result of using a prescribed atmosphere aerosol chemistry and a tripolar ocean–sea ice horizontal grid configuration that allows an increase of the ocean–sea ice component time steps. Ocean biogeochemistry can be activated for fully coupled and semi-coupled carbon cycle applications. This paper describes the model and evaluates its performance using observations and NorESM1-M as benchmarks. The evaluation emphasizes model stability, important large-scale features in the ocean and sea ice components, internal variability in the coupled system, and climate sensitivity. Simulation results from NorESM1-F in general agree well with observational estimates and show evident improvements over NorESM1-M, for example, in the strength of the meridional overturning circulation and sea ice simulation, both important metrics in simulating past and future climates. Whereas NorESM1-M showed a slight global cool bias in the upper oceans, NorESM1-F exhibits a global warm bias. In general, however, NorESM1-F has more similarities than dissimilarities compared to NorESM1-M, and some biases and deficiencies known in NorESM1-M remain.

scholarly journals Southern Ocean convection shutdown controls potential for long-term climate warming by greenhouse gases

2021 ◽  
Author(s):  
Ada Gjermundsen ◽  
Aleksi Nummelin ◽  
D. Olivié ◽  
Mats Bentsen ◽  
Øyvind Seland ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Atmospheric Carbon Dioxide ◽  
Marine Boundary Layer ◽  
Carbon Dioxide Concentration ◽  
Coupled Model ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Near Surface ◽  
Surface Warming

Abstract The effective climate sensitivity (EffCS) estimates the equilibrium near-surface temperature increase due to an doubling of the atmospheric carbon dioxide concentration, and is a widely used metric to characterise potential global warming. Cloud feedback, with considerable contribution from marine boundary layer clouds over the Southern Ocean (SO), has been identified as the main source to the spread and the increase in EffCS in the Earth System Models participating in phase 6 of the Coupled Model Intercomparison Project (CMIP6). We trace the difference in EffCS between the Community Earth System Model (CESM2, EffCS of 5.3K) and the Norwegian Earth System model (NorESM2; EffCS of 2.5K), to SO circulation response. NorESM2 stores more heat at depth than CESM2, which delays the SO surface warming, SO cloud response, and ultimately the global surface warming by centuries in comparison to CESM2. The link between SO and EffCS is seen across 41 CMIP6 models; those with a low EffCS exhibit substantial deep SO warming. The observed slow surface but fast subsurface SO warming supports the notion of SO control over EffCS.

scholarly journals The Australian Earth System Model: ACCESS-ESM1.5

2020 ◽  
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.

scholarly journals FOCI-MOPS v1 – Integration of Marine Biogeochemistry within the Flexible Ocean and Climate Infrastructure version 1 (FOCI 1) Earth system model

2022 ◽  
Author(s):  
Chia-Te Chien ◽  
Jonathan V. Durgadoo ◽  
Dana Ehlert ◽  
Ivy Frenger ◽  
David P. Keller ◽  
...  
Keyword(s):  
Climate Model ◽  
Coupled Model ◽  
Surface Air Temperature ◽  
Earth System Model ◽  
System Model ◽  
Biogeochemical Model ◽  
Historical Period ◽  
Earth System ◽  
Marine Biogeochemistry ◽  
Ocean Carbon

Abstract. The consideration of marine biogeochemistry is essential for simulating the carbon cycle in an Earth system model. Here we present the implementation and evaluation of a marine biogeochemical model, Model of Oceanic Pelagic Stoichiometry (MOPS) in the Flexible Ocean and Climate Infrastructure (FOCI) climate model. FOCI-MOPS enables the simulation of marine biological processes, the marine carbon, nitrogen and oxygen cycles, air-sea gas exchange of CO2 and O2, and simulations with prescribed atmospheric CO2 or CO2 emissions. A series of experiments covering the historical period (1850–2014) were performed following the DECK (Diagnostic, Evaluation and Characterization of Klima) and CMIP6 (Coupled Model Intercomparison Project 6) protocols. Overall, modelled biogeochemical tracer distributions and fluxes, as well as transient evolution in surface air temperature, air-sea CO2 fluxes, and changes of ocean carbon and heat, are in good agreement with observations. Modelled inorganic and organic tracer distributions are quantitatively evaluated by statistically-derived metrics. Results of the FOCI-MOPS model, also including sea surface temperature, surface pH, oxygen (100–600 m), nitrate (0–100 m), and primary production, are within the range of other CMIP6 model results. Overall, the evaluation of FOCI-MOPS indicates its suitability for Earth climate system simulations.

scholarly journals The EC-Earth3 Earth System Model for the Climate Model Intercomparison Project 6

2021 ◽  
Author(s):  
Ralf Döscher ◽  
Mario Acosta ◽  
Andrea Alessandri ◽  
Peter Anthoni ◽  
Almut Arneth ◽  
...  
Keyword(s):  
Physical Performance ◽  
Performance Metrics ◽  
Climate Model ◽  
Earth System Model ◽  
System Model ◽  
Historical Period ◽  
Earth System ◽  
Dynamic Features ◽  
The Earth ◽  
Intercomparison Project

Abstract. The Earth System Model EC-Earth3 for contributions to CMIP6 is documented here, with its flexible coupling framework, major model configurations, a methodology for ensuring the simulations are comparable across different HPC systems, and with the physical performance of base configurations over the historical period. The variety of possible configurations and sub-models reflects the broad interests in the EC-Earth community. EC-Earth3 key performance metrics demonstrate physical behaviour and biases well within the frame known from recent CMIP models. With improved physical and dynamic features, new ESM components, community tools, and largely improved physical performance compared to the CMIP5 version, EC-Earth3 represents a clear step forward for the only European community ESM. We demonstrate here that EC-Earth3 is suited for a range of tasks in CMIP6 and beyond.

scholarly journals The compact Earth system model OSCAR v2.2: description and first results

2017 ◽  
Vol 10 (1) ◽  
pp. 271-319 ◽  
Author(s):  
Thomas Gasser ◽  
Philippe Ciais ◽  
Olivier Boucher ◽  
Yann Quilcaille ◽  
Maxime Tortora ◽  
...  
Keyword(s):  
Atmospheric Carbon Dioxide ◽  
Stratospheric Ozone ◽  
Earth System Model ◽  
Tropospheric Chemistry ◽  
System Model ◽  
Future Climate Change ◽  
Historical Period ◽  
Earth System ◽  
Atmospheric Concentration ◽  
The Earth

Abstract. This paper provides a comprehensive description of OSCAR v2.2, a simple Earth system model. The general philosophy of development is first explained, followed by a complete description of the model's drivers and various modules. All components of the Earth system necessary to simulate future climate change are represented in the model: the oceanic and terrestrial carbon cycles – including a book-keeping module to endogenously estimate land-use change emissions – so as to simulate the change in atmospheric carbon dioxide; the tropospheric chemistry and the natural wetlands, to simulate that of methane; the stratospheric chemistry, for nitrous oxide; 37 halogenated compounds; changing tropospheric and stratospheric ozone; the direct and indirect effects of aerosols; changes in surface albedo caused by black carbon deposition on snow and land-cover change; and the global and regional response of climate – in terms of temperature and precipitation – to all these climate forcers. Following the probabilistic framework of the model, an ensemble of simulations is made over the historical period (1750–2010). We show that the model performs well in reproducing observed past changes in the Earth system such as increased atmospheric concentration of greenhouse gases or increased global mean surface temperature.

scholarly journals The Canadian Earth System Model version 5 (CanESM5.0.3)

2019 ◽  
Vol 12 (11) ◽  
pp. 4823-4873 ◽  
Author(s):  
Neil C. Swart ◽  
Jason N. S. Cole ◽  
Viatcheslav V. Kharin ◽  
Mike Lazare ◽  
John F. Scinocca ◽  
...  
Keyword(s):  
Land Surface ◽  
General Circulation ◽  
Large Scale ◽  
General Circulation Models ◽  
Earth System Model ◽  
System Model ◽  
Historical Period ◽  
Earth System ◽  
Historical Climate ◽  
Model Version

Abstract. The Canadian Earth System Model version 5 (CanESM5) is a global model developed to simulate historical climate change and variability, to make centennial-scale projections of future climate, and to produce initialized seasonal and decadal predictions. This paper describes the model components and their coupling, as well as various aspects of model development, including tuning, optimization, and a reproducibility strategy. We also document the stability of the model using a long control simulation, quantify the model's ability to reproduce large-scale features of the historical climate, and evaluate the response of the model to external forcing. CanESM5 is comprised of three-dimensional atmosphere (T63 spectral resolution equivalent roughly to 2.8∘) and ocean (nominally 1∘) general circulation models, a sea-ice model, a land surface scheme, and explicit land and ocean carbon cycle models. The model features relatively coarse resolution and high throughput, which facilitates the production of large ensembles. CanESM5 has a notably higher equilibrium climate sensitivity (5.6 K) than its predecessor, CanESM2 (3.7 K), which we briefly discuss, along with simulated changes over the historical period. CanESM5 simulations contribute to the Coupled Model Intercomparison Project phase 6 (CMIP6) and will be employed for climate science and service applications in Canada.

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