scholarly journals Progress towards a probabilistic Earth system model: examining the impact of stochasticity in the atmosphere and land component of EC-Earth v3.2

2019 ◽  
Vol 12 (7) ◽  
pp. 3099-3118 ◽  
Author(s):  
Kristian Strommen ◽  
Hannah M. Christensen ◽  
Dave MacLeod ◽  
Stephan Juricke ◽  
Tim N. Palmer
Keyword(s):  
Climate Model ◽  
Weather Forecasting ◽  
Southern Oscillation ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Beneficial Impact ◽  
The Impact ◽  
Mean State

Abstract. We introduce and study the impact of three stochastic schemes in the EC-Earth climate model: two atmospheric schemes and one stochastic land scheme. These form the basis for a probabilistic Earth system model in atmosphere-only mode. Stochastic parametrization have become standard in several operational weather-forecasting models, in particular due to their beneficial impact on model spread. In recent years, stochastic schemes in the atmospheric component of a model have been shown to improve aspects important for the models long-term climate, such as El Niño–Southern Oscillation (ENSO), North Atlantic weather regimes, and the Indian monsoon. Stochasticity in the land component has been shown to improve the variability of soil processes and improve the representation of heatwaves over Europe. However, the raw impact of such schemes on the model mean is less well studied. It is shown that the inclusion of all three schemes notably changes the model mean state. While many of the impacts are beneficial, some are too large in amplitude, leading to significant changes in the model's energy budget and atmospheric circulation. This implies that in order to maintain the benefits of stochastic physics without shifting the mean state too far from observations, a full re-tuning of the model will typically be required.

scholarly journals Introducing the Probabilistic Earth-System Model: Examining The Impact of Stochasticity in EC-Earth v3.2

2019 ◽  
Author(s):  
Kristian Strommen ◽  
Hannah M. Christensen ◽  
David MacLeod ◽  
Stephan Juricke ◽  
Tim N. Palmer
Keyword(s):  
Climate Model ◽  
Weather Forecasting ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Beneficial Impact ◽  
The Mean ◽  
The Impact ◽  
Mean State

Abstract. We introduce and study the impact of three stochastic schemes in the EC-Earth climate model, two atmospheric schemes and one stochastic land scheme. These form the basis for a probabilistic earth-system model in atmosphere-only mode. Stochastic parametrisations have become standard in several operational weather-forecasting models, in particular due to their beneficial impact on model spread. In recent years, stochastic schemes in the atmospheric component of a model have been shown to improve aspects important for the models long-term climate, such as ENSO, North Atlantic weather regimes and the Indian monsoon. Stochasticity in the land-component has been shown to improve variability of soil processes and improve the representation of heatwaves over Europe. However, the raw impact of such schemes on the model mean is less well studied, It is shown that the inclusion all three schemes notably change the model mean state. While many of the impacts are beneficial, some are too large in amplitude, leading to large changes in the model's energy budget. This implies that in order to keep the benefits of stochastic physics without shifting the mean state too far from observations, a full re-tuning of the model will typically be required.

scholarly journals Coupling of a sediment diagenesis model (MEDUSA) and an Earth system model (CESM1.2): a contribution toward enhanced marine biogeochemical modelling and long-term climate simulations

2019 ◽  
Author(s):  
Takasumi Kurahashi-Nakamura ◽  
André Paul ◽  
Guy Munhoven ◽  
Ute Merkel ◽  
Michael Schulz
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Coupled Model ◽  
Earth System Model ◽  
System Model ◽  
Future Application ◽  
Coupling Scheme ◽  
Earth System ◽  
Climate Simulations

Abstract. We developed a coupling scheme for the Community Earth System Model version 1.2 (CESM1.2) and the Model of Early Diagenesis in the Upper Sediment of Adjustable complexity (MEDUSA), and explored the effects of the coupling on solid components in the upper sediment and on bottom seawater chemistry by comparing the coupled model's behaviour with that of the uncoupled CESM having a simplified treatment of sediment processes. CESM is a fully-coupled atmosphere-ocean-sea ice-land model and its ocean component (the Parallel Ocean Program version 2, POP2) includes a biogeochemical component (BEC). MEDUSA was coupled to POP2 in an off-line manner so that each of the models ran separately and sequentially with regular exchanges of necessary boundary condition fields. This development was done with the ambitious aim of a future application for long-term (spanning a full glacial cycle; i.e., ~ 105 years) climate simulations with a state-of-the-art comprehensive climate model including the carbon cycle, and was motivated by the fact that until now such simulations have been done only with less-complex climate models. We found that the sediment-model coupling already had non-negligible immediate advantages for ocean biogeochemistry in millennial-time-scale simulations. First, the MEDUSA-coupled CESM outperformed the uncoupled CESM in reproducing an observation-based global distribution of sediment properties, especially for organic carbon and opal. Thus, the coupled model is expected to act as a better bridge between climate dynamics and sedimentary data, which will provide another measure of model performance. Second, in our experiments, the MEDUSA-coupled model and the uncoupled model had a difference of 0.2‰ or larger in terms of δ13C of bottom water over large areas, which implied potential significant model biases for bottom seawater chemical composition due to a different way of sediment treatment. Such a model bias would be a fundamental issue for paleo model–data comparison often relying on data derived from benthic foraminifera.

Model Description and Evaluation of FIO Earth System Model (FIO-ESM) version 2.0

2021 ◽  
Author(s):  
Ying Bao ◽  
Zhenya Song ◽  
Fangli Qiao
Keyword(s):  
Surface Wave ◽  
Climate Model ◽  
Southern Oscillation ◽  
Earth System Model ◽  
Heat Fluxes ◽  
Meridional Overturning Circulation ◽  
System Model ◽  
Model Description ◽  
Earth System ◽  
Version 2.0

<p>The First Institute of Oceanography Earth System Model (FIO-ESM) version 2.0 was developed and participated in the Climate Model Intercomparison Project phase 6 (CMIP6). In comparison with FIO-ESM v1.0, all component models of FIO-ESM v2.0 are updated, and their resolutions are fined. In addition to the non-breaking surface wave-induced mixing (Bv), which has also been included in FIO-ESM v1.0, there are three more distinctive physical processes in FIO-ESM v2.0, including the effect of surface wave Stokes drifts on air-sea momentum and heat fluxes, the effect of wave-induce sea spray on air-sea heat fluxes and the effect of sea surface temperature (SST) diurnal cycle on air-sea heat and gas fluxes. The FIO-ESM v2.0 has conducted the CMIP6 Diagnostic, Evaluation and Characterization of Klima (DECK) , historical and futrue scenario experiments. The results of pre-industrial run show the stability of the climate model. The historical simulation of FIO-ESM v2.0 for 1850-2014 is evaluated, including the surface air temperature (SAT), precipitation, SST, Atlantic Meridional Overturning Circulation (AMOC), El Niño-Southern Oscillation (ENSO), etc. The climate changes with respect to SAT and SST global warming and decreasing AMOC are well reproduced by FIO-ESM v2.0. The correlation coefficient of the global annual mean SAT anomaly can reach 0.92 with observations. In particular, the large warm SST bias at the east coast of tropical Pacific from FIO-ESM v1.0, which is a common challenge for all climate models, is dramatically reduced in FIO-ESM v2.0 and the ENSO period within the range of 2-7 years is well reproduced with the largest variation of SST anomalies occurring in boreal winter, which is consistent with observations.</p>

scholarly journals Description and basic evaluation of Beijing Normal University Earth System Model (BNU-ESM) version 1

2014 ◽  
Vol 7 (5) ◽  
pp. 2039-2064 ◽  
Author(s):  
D. Ji ◽  
L. Wang ◽  
J. Feng ◽  
Q. Wu ◽  
H. Cheng ◽  
...  
Keyword(s):  
Annual Cycle ◽  
Climate Model ◽  
Southern Oscillation ◽  
Surface Air Temperature ◽  
Earth System Model ◽  
Meridional Overturning Circulation ◽  
System Model ◽  
Global Ocean ◽  
Earth System ◽  
Normal University

Abstract. An earth system model has been developed at Beijing Normal University (Beijing Normal University Earth System Model, BNU-ESM); the model is based on several widely evaluated climate model components and is used to study mechanisms of ocean-atmosphere interactions, natural climate variability and carbon-climate feedbacks at interannual to interdecadal time scales. In this paper, the model structure and individual components are described briefly. Further, results for the CMIP5 (Coupled Model Intercomparison Project phase 5) pre-industrial control and historical simulations are presented to demonstrate the model's performance in terms of the mean model state and the internal variability. It is illustrated that BNU-ESM can simulate many observed features of the earth climate system, such as the climatological annual cycle of surface-air temperature and precipitation, annual cycle of tropical Pacific sea surface temperature (SST), the overall patterns and positions of cells in global ocean meridional overturning circulation. For example, the El Niño-Southern Oscillation (ENSO) simulated in BNU-ESM exhibits an irregular oscillation between 2 and 5 years with the seasonal phase locking feature of ENSO. Important biases with regard to observations are presented and discussed, including warm SST discrepancies in the major upwelling regions, an equatorward drift of midlatitude westerly wind bands, and tropical precipitation bias over the ocean that is related to the double Intertropical Convergence Zone (ITCZ).

scholarly journals Description and basic evaluation of BNU-ESM version 1

2014 ◽  
Vol 7 (2) ◽  
pp. 1601-1647 ◽  
Author(s):  
D. Ji ◽  
L. Wang ◽  
J. Feng ◽  
Q. Wu ◽  
H. Cheng ◽  
...  
Keyword(s):  
Annual Cycle ◽  
Climate Model ◽  
Southern Oscillation ◽  
Surface Air Temperature ◽  
Earth System Model ◽  
Meridional Overturning Circulation ◽  
System Model ◽  
Global Ocean ◽  
Earth System ◽  
Normal University

Abstract. An earth system model has been developed at Beijing Normal University (Beijing Normal University Earth System Model, BNU-ESM); the model is based on several widely evaluated climate model components and is used to study mechanisms of ocean–atmosphere interactions, natural climate variability and carbon-climate feedbacks at interannual to interdecadal time scales. In this paper, the model structure and individual components are described briefly. Further, results for the CMIP5 (Coupled Model Intercomparison Project phase 5) pre-industrial control and historical simulations are presented to demonstrate the model's performance in terms of the mean model state and the internal variability. It is illustrated that BNU-ESM can simulate many observed features of the earth climate system, such as the climatological annual cycle of surface air temperature and precipitation, annual cycle of tropical Pacific sea surface temperature (SST), the overall patterns and positions of cells in global ocean meridional overturning circulation. For example, the El Niño-Southern Oscillation (ENSO) simulated in BNU-ESM exhibits an irregular oscillation between 2 and 5 years with the seasonal phase locking feature of ENSO. Important biases with regard to observations are presented and discussed, including warm SST discrepancies in the major upwelling regions, an equatorward drift of midlatitude westerly wind bands, and tropical precipitation bias over the ocean that is related to the double Intertropical Convergence Zone (ITCZ).

Korea Institute of Ocean Science & Technology Earth System Model and its simulation characteristics

2020 ◽  
Author(s):  
Young Ho Kim ◽  
Gyundo Pak ◽  
Yign Noh ◽  
Myong-In Lee ◽  
Sang-Wook Yeh ◽  
...  
Keyword(s):  
Climate Model ◽  
Southern Oscillation ◽  
Atmospheric Temperature ◽  
Earth System Model ◽  
System Model ◽  
Superior Performance ◽  
Cold Bias ◽  
Geophysical Fluid Dynamics Laboratory ◽  
Earth System ◽  
Ocean Science

<p>In our presentation, we will show the performance of a new earth system model developed at the Korea Institute of Ocean Science and Technology (KIOST), called the KIOST-ESM. The KIOST-ESM is based on a low-resolution version of the Geophysical Fluid Dynamics Laboratory Climate Model version 2.5. The main changes made to the base model include using new cumulus convection and ocean mixed layer parameterization schemes, which improve the model fidelity significantly. In addition, the KIOST-ESM adopts dynamic vegetation and new soil respiration schemes in its land model component. The performance of the KIOST-ESM was assessed in pre-industrial and historical simulations that are made as part of its participation into Climate Model Intercomparison Project phase 6. The response of the earth system to increases in greenhouse gas concentrations were analyzed in the ScenarioMIP simulations. The KIOST-ESM exhibited superior performance compared to the base model in terms of the mean sea surface temperature over the Southern Ocean and over the cold tongue in the tropical Pacific. The KIOST-ESM can also simulate the dominant tropical variability in the intraseasonal (Madden-Julian Oscillation) and interannual (El Niño-Southern Oscillation) timescales more realistically than the base model. On the other hand, like many other contemporary ESMs, the KIOST-ESM showed notable cold bias in the Northern Hemisphere, and the so-called double-Intertropical Convergence Zone bias remains. The ScenarioMIP results confirm the global average surface atmospheric temperature responds to the CO<sub>2</sub> concentration.</p>

scholarly journals Simulations of the Mid-Pliocene Warm Period using the NASA/GISS ModelE2-R Earth System Model

2012 ◽  
Vol 5 (3) ◽  
pp. 2811-2842 ◽  
Author(s):  
M. A. Chandler ◽  
L. E. Sohl ◽  
J. A. Jonas ◽  
H. J. Dowsett
Keyword(s):  
North Atlantic ◽  
Climate Models ◽  
Climate Model ◽  
Geographic Region ◽  
Earth System Model ◽  
Warm Period ◽  
System Model ◽  
Earth System ◽  
Intergovernmental Panel ◽  
Future Global Warming

Abstract. Climate reconstructions of the mid-Pliocene Warm Period (mPWP) bear many similarities to aspects of future global warming as projected by the Intergovernmental Panel on Climate Change. In particular, marine and terrestrial paleoclimate data point to high latitude temperature amplification, with associated decreases in sea ice and land ice and altered vegetation distributions that show expansion of warmer climate biomes into higher latitudes. NASA GISS climate models have been used to study the Pliocene climate since the USGS PRISM project first identified that the mid-Pliocene North Atlantic sea surface temperatures were anomalously warm. Here we present the most recent simulations of the Pliocene using the AR5/CMIP5 version of the GISS Earth System Model known as ModelE2-R. These simulations constitute the NASA contribution to the Pliocene Model Intercomparison Project (PlioMIP) Experiment 2. Many findings presented here corroborate results from other PlioMIP multi-model ensemble papers, but we also emphasize features in the ModelE2-R simulations that are unlike the ensemble means. We provide discussion of features that show considerable improvement compared with simulations from previous versions of the NASA GISS models, improvement defined here as simulation results that more closely resemble the ocean core data as well as the PRISM3D reconstructions of the mid-Pliocene climate. In some regions even qualitative agreement between model results and paleodata are an improvement over past studies, but the dramatic warming in the North Atlantic and Greenland-Iceland-Norwegian Sea in these new simulations is by far the most accurate portrayal ever of this key geographic region by the GISS climate model. Our belief is that continued development of key physical routines in the atmospheric model, along with higher resolution and recent corrections to mixing parameterizations in the ocean model, have led to an Earth System Model that will produce more accurate projections of future climate.

scholarly journals Comparison of ocean vertical mixing schemes in the Max Plank Institute Earth System Model (MPI-ESM1.2)

2020 ◽  
Author(s):  
Oliver Gutjahr ◽  
Nils Brüggemann ◽  
Helmuth Haak ◽  
Johann H. Jungclaus ◽  
Dian A. Putrasahan ◽  
...  
Keyword(s):  
Vertical Mixing ◽  
Global Scale ◽  
Earth System Model ◽  
System Model ◽  
The Arctic ◽  
Earth System ◽  
Max Planck ◽  
Vertical Diffusion ◽  
Mixing Schemes ◽  
Mean State

Abstract. We compare the effects of four different ocean vertical mixing schemes on the ocean mean state simulated by the Max Planck Institute Earth System Model (MPI-ESM1.2) in the framework of the Community Vertical Mixing (CVMix) library. Besides the PP and KPP scheme, we implemented the TKE scheme and a recently developed prognostic scheme for internal wave energy and its dissipation (IDEMIX) to replace the often assumed constant background diffusivity in the ocean interior. We analyse in particular the effects of IDEMIX on the ocean mean state, when combined with TKE (TKE+IDEMIX). In general, we find little sensitivity of the ocean surface, but considerable effects for the interior ocean. Overall, we cannot classify any scheme as superior, because they modify biases that vary by region or variable, but produce a similar pattern on the global scale. However, using a more realistic and energetically consistent scheme (TKE+IDEMIX) produces a more heterogeneous pattern of vertical diffusion, with lower diffusivity in deep and flat-bottom basins and elevated turbulence over rough topography. In addition, TKE+IDEMIX improves the circulation in the Nordic Seas and Fram Strait, thus reducing the warm bias of the Atlantic water (AW) layer in the Arctic Ocean to a similar extent as has been demonstrated with eddy-resolving ocean models. We conclude that although shortcomings due to model resolution determine the global-scale bias pattern, the choice of the vertical mixing scheme may play an important role for regional biases.

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.

Recent developments on the Earth System Model Evaluation Tool

2021 ◽  
Author(s):  
Bouwe Andela ◽  
Fakhereh Alidoost ◽  
Lukas Brunner ◽  
Jaro Camphuijsen ◽  
Bas Crezee ◽  
...  
Keyword(s):  
Model Evaluation ◽  
Performance Metrics ◽  
Climate Model ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Evaluation Tool ◽  
Scientific Review ◽  
The Earth ◽  
User Friendly

<p>The Earth System Model Evaluation Tool (ESMValTool) is a free and open-source community diagnostic and performance metrics tool for the evaluation of Earth system models such as those participating in the Coupled Model Intercomparison Project (CMIP). Version 2 of the tool (Righi et al. 2020, www.esmvaltool.org) features a brand new design composed of a core that finds and processes data according to a ‘recipe’ and an extensive collection of ready-to-use recipes and associated diagnostic codes for reproducing results from published papers. Development and discussion of the tool (mostly) takes place in public on https://github.com/esmvalgroup and anyone with an interest in climate model evaluation is welcome to join there.</p><p> </p><p>Since the initial release of version 2 in the summer of 2020, many improvements have been made to the tool. It is now more user friendly with extensive documentation available on docs.esmvaltool.org and a step by step online tutorial. Regular releases, currently planned three times a year, ensure that recent contributions become available quickly while still ensuring a high level of quality control. The tool can be installed from conda, but portable docker and singularity containers are also available.</p><p> </p><p>Recent new features include a more user-friendly command-line interface, citation information per figure including CMIP6 data citation using ES-DOC, more and faster preprocessor functions that require less memory, automatic corrections for a larger number of CMIP6 datasets, support for more observational and reanalysis datasets, and more recipes and diagnostics.</p><p> </p><p>The tool is now also more reliable, with improved automated testing through more unit tests for the core, as well as a recipe testing service running at DKRZ for testing the scientific recipes and diagnostics that are bundled into the tool. The community maintaining and developing the tool is growing, making the project less dependent on individual contributors. There are now technical and scientific review teams that review new contributions for technical quality and scientific correctness and relevance respectively, two new principal investigators for generating a larger support base in the community, and a newly created user engagement team that is taking care of improving the overall user experience.</p>

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