Decadal climate predictions with the Canadian Earth System Model version 5 (CanESM5)

Abstract. The Canadian Earth System Model version 5 (CanESM5) developed at Environment and Climate Change Canada's Canadian Centre for Climate Modelling and Analysis (CCCma) is participating in phase 6 of the Coupled Model Intercomparison Project (CMIP6). A 40-member ensemble of CanESM5 retrospective decadal forecasts (or hindcasts) is integrated for 10 years from realistic initial states once a year during 1961 to the present using prescribed external forcing. The results are part of CCCma's contribution to the Decadal Climate Prediction Project (DCPP) component of CMIP6. This paper evaluates CanESM5 large ensemble decadal hindcasts against observational benchmarks and against historical climate simulations initialized from pre-industrial control run states. The focus is on the evaluation of the potential predictability and actual skill of annual and multi-year averages of key oceanic and atmospheric fields at regional and global scales. The impact of initialization on prediction skill is quantified from the hindcasts decomposition into uninitialized and initialized components. The dependence of potential and actual skill on ensemble size is examined. CanESM5 decadal hindcasts skillfully predict upper-ocean states and surface climate with a significant impact from initialization that depend on climate variable, forecast range, and geographic location. Deficiencies in the skill of North Atlantic surface climate are identified and potential causes discussed. The inclusion of biogeochemical modules in CanESM5 enables the prediction of carbon cycle variables which are shown to be potentially skillful on decadal timescales, with a strong long-lasting impact from initialization on skill in the ocean and a moderate short-lived impact on land.

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Decadal climate predictions with the Canadian Earth System Model version 5 (CanESM5)

10.5194/gmd-2021-1 ◽

2021 ◽

Author(s):

Reinel Sospedra-Alfonso ◽

William J. Merryfield ◽

George J. Boer ◽

Viatsheslav V. Kharin ◽

Woo-Sung Lee ◽

...

Keyword(s):

Coupled Model ◽

Earth System Model ◽

System Model ◽

Climate Modelling ◽

Earth System ◽

Potential Predictability ◽

Model Version ◽

Surface Climate ◽

Decadal Climate ◽

The Impact

Abstract. The Canadian Earth System Model version 5 (CanESM5) developed at Environment and Climate Change Canada's Canadian Centre for Climate Modelling and Analysis (CCCma) is participating in phase 6 of the Coupled Model Intercomparison Project (CMIP6). A 40-member ensemble of CanESM5 historical decadal forecasts (or hindcasts) is integrated for ten years from realistic initial states during 1961 to present using prescribed external forcing. The results are part of CCCma's contribution to the Decadal Climate Prediction Project (DCPP) component of CMIP6. This paper evaluates CanESM5 large ensemble decadal hindcasts against observational benchmarks and against historical climate simulations initialized from preindustrial control run states. The focus is on the evaluation of the potential predictability and actual skill of annual and multi-year averages of key oceanic and atmospheric fields at regional and global scales. The impact of initialization on prediction skill is quantified from the hindcasts decomposition into uninitialized and initialized components. The dependence of potential and actual skill on ensemble size is examined. CanESM5 decadal hindcasts skilfully predict upper-ocean states and surface climate with a significant impact from initialization that depend on climate variable, forecast range, and geographic location. Deficiencies in the skill of North Atlantic surface climate are identified and potential causes discussed. The inclusion of biogeochemical modules in CanESM5 enables the prediction of carbon cycle variables which are shown to be skilful on decadal time scales, with a strong long-lasting impact from initialization on skill in the ocean and a moderate short-lived impact on land.

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Coupling the dynamic vegetation model LPJmL5.1 to an Earth system model – towards POEM1.0

10.5194/egusphere-egu2020-17982 ◽

2020 ◽

Author(s):

Markus Drüke ◽

Werner von Bloh ◽

Stefan Petri ◽

Sibyll Schaphoff ◽

Boris Sakschewski ◽

...

Keyword(s):

Amazon Basin ◽

Model Performance ◽

Coupled Model ◽

Earth System Model ◽

System Model ◽

Earth System ◽

Vegetation Model ◽

Canopy Layer ◽

Dynamic Global Vegetation Model ◽

The Impact

Feedbacks between biosphere and other components of the Earth system are challenging to model accurately and therefore are often omitted or oversimplified in Earth system models (ESMs). However, their importance is increasingly recognized as rapid disturbances due to anthropogenic (e.g., deforestation) or natural (e.g. regional increase in fires) drivers are already observed.Here we couple the well established and comprehensively validated dynamic global vegetation model LPJmL5.1 (von Bloh et al., 2018) to an Earth System model CM2Mc (MOM5/AM2, Galbraith et al. 2011). We replace the simple static vegetation model LaD with LPJmL5.1 and couple the water- and energy cycle by using GFDL&#8217;s Flexible Modeling System (FMS). In order to stabilize the model performance, several adjustments to LPJmL5.1 had to be done, including the introduction of a subdaily cycle for the energy and water calculations, the implementation of a conductance of the soil evaporation and plant interception, the calculation of a canopy layer humidity, and the surface energy balance in order to calculate the surface and canopy layer temperature within LPJmL5.1.The coupled system allows us to answer questions regarding ecosystem stability with a complete energy and water cycle. For example, changes in the vegetation have a large impact on atmosphere dynamics, which in turn affects precipitation and feeds back into vegetation growth and mortality. To examine this feedback a simple experiment is performed by deforesting the whole Amazon basin and replacing it with grassland. Our results show decreasing precipitation and increasing canopy temperature which becomes a stable climate state in this treeless scenario. Future applications of the coupled model may include the investigation of tipping points in the biosphere, the impact of different atmospheric CO2 concentrations or climate change and land-use change scenarios.&#160;

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The GFDL Earth System Model Version 4.1 (GFDL‐ESM 4.1): Overall Coupled Model Description and Simulation Characteristics

Journal of Advances in Modeling Earth Systems ◽

10.1029/2019ms002015 ◽

2020 ◽

Vol 12 (11) ◽

Cited By ~ 12

Author(s):

J. P. Dunne ◽

L. W. Horowitz ◽

A. J. Adcroft ◽

P. Ginoux ◽

I. M. Held ◽

...

Keyword(s):

Coupled Model ◽

Earth System Model ◽

System Model ◽

Model Description ◽

Earth System ◽

Model Version

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Taiwan Earth System Model Version 1: Description and Evaluation of Mean State

10.5194/gmd-2019-377 ◽

2020 ◽

Author(s):

Wei-Liang Lee ◽

Yi-Chi Wang ◽

Chein-Jung Shiu ◽

I-chun Tsai ◽

Chia-Ying Tu ◽

...

Keyword(s):

Sea Ice ◽

Deep Convection ◽

Three Dimensional ◽

Coupled Model ◽

Earth System Model ◽

System Model ◽

Earth System ◽

Sea Ice Concentration ◽

Model Stability ◽

Model Version

Abstract. The Taiwan Earth System Model (TaiESM) version 1 is developed based on Community Earth System Model version 1.2.2 of National Center for Atmospheric Research. Several innovated physical and chemical parameterizations, including trigger functions for deep convection, cloud macrophysics, aerosol, and three-dimensional radiation–topography interaction, as well as a one-dimensional mixed-layer model optional for the atmosphere component, are incorporated. The precipitation variability, such as diurnal cycle and propagation of convection systems, is improved in TaiESM. TaiESM demonstrates good model stability in the 500-year preindustrial simulation in terms of the net flux at the top of the model, surface temperatures, and sea ice concentration. In the historical simulation, although the warming before 1935 is weak, TaiESM well captures the increasing trend of temperature after 1950. The current climatology of TaiESM during 1979–2005 is evaluated by observational and reanalysis datasets. Cloud amounts are too large in TaiESM, but their cloud forcing is only slightly weaker than observational data. The mean bias of the sea surface temperature is almost zero, whereas the surface air temperatures over land and sea ice regions exhibit cold biases. The overall performance of TaiESM is above average among models in Coupled Model Intercomparison Project phase 5, particularly that the bias of precipitation is smallest. However, several common discrepancies shared by most models still exist, such as the double Intertropical Convergence Zone bias in precipitation and warm bias over the Southern Ocean.

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Quantifying CanESM5 and EAMv1 sensitivities to volcanic forcing for the CMIP6 historical experiment

10.5194/gmd-2019-381 ◽

2020 ◽

Author(s):

Landon A. Rieger ◽

Jason N. S. Cole ◽

John C. Fyfe ◽

Stephen Po-Chedley ◽

Philip J. Cameron-Smith ◽

...

Keyword(s):

Radiative Forcing ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Earth System Model ◽

System Model ◽

Global Ocean ◽

Earth System ◽

Model Version ◽

Aerosol Forcing ◽

The Impact

Abstract. Large volcanic eruptions reaching the stratosphere have caused marked perturbations to the global climate including cooling at the Earth's surface, changes in large-scale circulation and precipitation patterns and marked temporary reductions in global ocean heat content. Many studies have investigated these effects using climate models, however uncertainties remain in the modelled response to these eruptions. This is due in part to the diversity of forcing datasets that are used to prescribe the distribution of stratospheric aerosols resulting from these volcanic eruptions, as well as uncertainties in optical property derivations from these datasets. To reduce these uncertainties in the Coupled Model Intercomparison Project 6 (CMIP6) a combined stratospheric aerosol dataset, the Global Space-based Stratospheric Aerosol Climatology, GloSSAC, was constructed. Along with information from ice-cores and sun photometers, GloSSAC was used to generate aerosol distributions, characteristics and optical properties and construct a consistent stratospheric aerosol forcing dataset for models participating in CMIP6. This version 3 of the stratospheric aerosol forcing has been endorsed for use in all contributing CMIP6 simulations. Recent updates to the underlying GloSSAC from version 1 to version 1.1 affected the 1991 to 1994 period and necessitated an update to the stratospheric aerosol forcing from version 3 to version 4. As version 3 remains the official CMIP6 input, quantification of the impact on radiative forcing and climate is both relevant and timely for interpreting results from experiments such as the CMIP6 historical simulations. This study uses the Canadian Earth System Model version 5 (CanESM5) to estimate the difference in instantaneous radiative forcing in simulated post-Pinatubo climate response when using version 4 instead of version 3. Differences in temperature, precipitation, and radiative forcings are generally found to be small compared to internal variability. To further elucidate sensitivities that are representative of the CMIP6 model suite, additional simulations are performed using the Energy Exascale Earth System Model (E3SM) Atmosphere Model version 1 (EAMv1), which also indicates that the impact of the update to GloSSAC version 4 on climate are relatively minor. An exception to this is differences in temperature anomalies in the stratosphere, which can be as large as 3 °C following the eruption of Mt. Pinatubo.

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Quantifying CanESM5 and EAMv1 sensitivities to Mt. Pinatubo volcanic forcing for the CMIP6 historical experiment

Geoscientific Model Development ◽

10.5194/gmd-13-4831-2020 ◽

2020 ◽

Vol 13 (10) ◽

pp. 4831-4843 ◽

Cited By ~ 1

Author(s):

Landon A. Rieger ◽

Jason N. S. Cole ◽

John C. Fyfe ◽

Stephen Po-Chedley ◽

Philip J. Cameron-Smith ◽

...

Keyword(s):

Radiative Forcing ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Earth System Model ◽

System Model ◽

Global Ocean ◽

Earth System ◽

Model Version ◽

Aerosol Forcing ◽

The Impact

Abstract. Large volcanic eruptions reaching the stratosphere have caused marked perturbations to the global climate including cooling at the Earth's surface, changes in large-scale circulation and precipitation patterns and marked temporary reductions in global ocean heat content. Many studies have investigated these effects using climate models; however, uncertainties remain in the modelled response to these eruptions. This is due in part to the diversity of forcing datasets that are used to prescribe the distribution of stratospheric aerosols resulting from these volcanic eruptions, as well as uncertainties in optical property derivations from these datasets. To improve this situation for the sixth phase of the Coupled Model Intercomparison Project (CMIP6), a two-step process was undertaken. First, a combined stratospheric aerosol dataset, the Global Space-based Stratospheric Aerosol Climatology (GloSSAC; 1979–2016), was constructed. Next, GloSSAC, along with information from ice cores and Sun photometers, was used to generate aerosol distributions, characteristics and optical properties to construct a more consistent stratospheric aerosol forcing dataset for models participating in CMIP6. This “version 3” of the stratospheric aerosol forcing has been endorsed for use in all contributing CMIP6 simulations. Recent updates to the underlying GloSSAC from version 1 to version 1.1 affected the 1991–1994 period and necessitated an update to the stratospheric aerosol forcing from version 3 to version 4. As version 3 remains the official CMIP6 input, quantification of the impact on radiative forcing and climate is both relevant and timely for interpreting results from experiments such as the CMIP6 historical simulations. This study uses two models, the Canadian Earth System Model version 5 (CanESM5) and the Energy Exascale Earth System Model (E3SM) Atmosphere Model version 1 (EAMv1), to estimate the difference in instantaneous radiative forcing in simulated post-Pinatubo climate response when using version 4 instead of version 3. Differences in temperature, precipitation and radiative forcings are generally found to be small compared to internal variability. An exception to this is differences in monthly temperature anomalies near 24 km altitude in the tropics, which can be as large as 3 ∘C following the eruption of Mt. Pinatubo.

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Taiwan Earth System Model Version 1: description and evaluation of mean state

Geoscientific Model Development ◽

10.5194/gmd-13-3887-2020 ◽

2020 ◽

Vol 13 (9) ◽

pp. 3887-3904

Author(s):

Wei-Liang Lee ◽

Yi-Chi Wang ◽

Chein-Jung Shiu ◽

I-chun Tsai ◽

Chia-Ying Tu ◽

...

Keyword(s):

Sea Ice ◽

Deep Convection ◽

Three Dimensional ◽

Coupled Model ◽

Earth System Model ◽

System Model ◽

Earth System ◽

Sea Ice Concentration ◽

Model Stability ◽

Model Version

Abstract. The Taiwan Earth System Model (TaiESM) version 1 is developed based on Community Earth System Model version 1.2.2 of National Center for Atmospheric Research. Several innovative physical and chemical parameterizations, including trigger functions for deep convection, cloud macrophysics, aerosol, and three-dimensional radiation–topography interaction, as well as a one-dimensional mixed-layer model optional for the atmosphere component, are incorporated. The precipitation variability, such as diurnal cycle and propagation of convection systems, is improved in TaiESM. TaiESM demonstrates good model stability in the 500-year preindustrial simulation in terms of the net flux at the top of the model, surface temperatures, and sea ice concentration. In the historical simulation, although the warming before 1935 is weak, TaiESM captures the increasing trend of temperature after 1950 well. The current climatology of TaiESM during 1979–2005 is evaluated by observational and reanalysis datasets. Cloud amounts are too large in TaiESM, but their cloud forcing is only slightly weaker than observational data. The mean bias of the sea surface temperature is almost 0, whereas the surface air temperatures over land and sea ice regions exhibit cold biases. The overall performance of TaiESM is above average among models in Coupled Model Intercomparison Project phase 5, particularly in that the bias of precipitation is smallest. However, several common discrepancies shared by most models still exist, such as the double Intertropical Convergence Zone bias in precipitation and warm bias over the Southern Ocean.

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