scholarly journals Simulating the mid-Holocene, last interglacial and mid-Pliocene climate with EC-Earth3-LR

2021 ◽  
Vol 14 (2) ◽  
pp. 1147-1169
Author(s):  
Qiong Zhang ◽  
Ellen Berntell ◽  
Josefine Axelsson ◽  
Jie Chen ◽  
Zixuan Han ◽  
...  
Keyword(s):  
Global Warming ◽  
Large Scale ◽  
Climate Changes ◽  
Southern Oscillation ◽  
Earth Model ◽  
Earth System ◽  
Model Intercomparison ◽  
Test Bed ◽  
Last Interglacial ◽  
Intercomparison Project

Abstract. As global warming is proceeding due to rising greenhouse gas concentrations, the Earth system moves towards climate states that challenge adaptation. Past Earth system states are offering possible modelling systems for the global warming of the coming decades. These include the climate of the mid-Pliocene (∼ 3 Ma), the last interglacial (∼ 129–116 ka) and the mid-Holocene (∼ 6 ka). The simulations for these past warm periods are the key experiments in the Paleoclimate Model Intercomparison Project (PMIP) phase 4, contributing to phase 6 of the Coupled Model Intercomparison Project (CMIP6). Paleoclimate modelling has long been regarded as a robust out-of-sample test bed of the climate models used to project future climate changes. Here, we document the model setup for PMIP4 experiments with EC-Earth3-LR and present the large-scale features from the simulations for the mid-Holocene, the last interglacial and the mid-Pliocene. Using the pre-industrial climate as a reference state, we show global temperature changes, large-scale Hadley circulation and Walker circulation, polar warming, global monsoons and the climate variability modes – El Niño–Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO). EC-Earth3-LR simulates reasonable climate responses during past warm periods, as shown in the other PMIP4-CMIP6 model ensemble. The systematic comparison of these climate changes in past three warm periods in an individual model demonstrates the model's ability to capture the climate response under different climate forcings, providing potential implications for confidence in future projections with the EC-Earth model.

scholarly journals Simulating the mid-Holocene, Last Interglacial and mid-Pliocene climate with EC-Earth3-LR

2020 ◽  
Author(s):  
Qiong Zhang ◽  
Qiang Li ◽  
Qiang Zhang ◽  
Ellen Berntell ◽  
Josefine Axelsson ◽  
...  
Keyword(s):  
Large Scale ◽  
Climate Changes ◽  
Climate Models ◽  
Coupled Model ◽  
Walker Circulation ◽  
Earth Model ◽  
Model Intercomparison ◽  
Test Bed ◽  
Last Interglacial ◽  
Intercomparison Project

Abstract. Paleoclimate modelling has long been regarded as a strong out-of-sample test-bed of the climate models that are used for the projection of future climate changes. For the first time, the EC-Earth model contributes to the Paleoclimate Model Intercomparison Project (PMIP) phase 4, which is part of the current sixth phase of the Coupled Model Intercomparison Project (CMIP6). Here, we document the model setup for PMIP4 experiments with EC-Earth3-LR and present the results on the large-scale features from the completed production simulations for the three past warm periods (mid-Holocene, Last Interglacial, and mid-Pliocene). Using the pre-industrial climate as a reference state, we show the changes in global temperature, large scale Hadley circulation and Walker circulation, polar warming and global monsoons, as well as the climate variability modes (ENSO, PDO, AMO). The EC-Earth3-LR simulates reasonable climate responses during past warm periods as shown in the other PMIP4-CMIP6 model ensemble. The systematic comparison of these climate changes in three past warm periods in an individual model demonstrates the ability of the model to capture the climate response under different climate forcings, providing potential implications for confidence in future projections with EC-Earth model.

scholarly journals CAS-ESM2.0 Model Datasets for the CMIP6 Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP)

2021 ◽  
Author(s):  
Jiangbo Jin ◽  
He Zhang ◽  
Xiao Dong ◽  
Hailong Liu ◽  
Minghua Zhang ◽  
...  
Keyword(s):  
Sea Level ◽  
Ocean Circulation ◽  
General Circulation ◽  
Climate Changes ◽  
Meridional Overturning Circulation ◽  
Global Ocean ◽  
Earth System ◽  
Model Intercomparison ◽  
Ocean Climate ◽  
Intercomparison Project

AbstractThe second version of the Chinese Academy of Sciences Earth System Model (CAS-ESM2.0) is participating in the Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP) experiments in phase 6 of the Coupled Model Intercomparison Project (CMIP6). The purpose of FAFMIP is to understand and reduce the uncertainty of ocean climate changes in response to increased CO2 forcing in atmosphere-ocean general circulation models (AOGCMs), including the simulations of ocean heat content (OHC) change, ocean circulation change, and sea level rise due to thermal expansion. FAFMIP experiments (including faf-heat, faf-stress, faf-water, faf-all, faf-passiveheat, faf-heat-NA50pct and faf-heat-NA0ct) have been conducted. All of the experiments were integrated over a 70-year period and the corresponding data have been uploaded to the Earth System Grid Federation data server for CMIP6 users to download. This paper describes the experimental design and model datasets and evaluates the preliminary results of CAS-ESM2.0 simulations of ocean climate changes in the FAFMIP experiments. The simulations of the changes in global ocean temperature, Atlantic Meridional Overturning Circulation (AMOC), OHC., and dynamic sea level (DSL), are all reasonably reproduced.

California Winter Precipitation Change under Global Warming in the Coupled Model Intercomparison Project Phase 5 Ensemble

2013 ◽  
Vol 26 (17) ◽  
pp. 6238-6256 ◽  
Author(s):  
J. David Neelin ◽  
Baird Langenbrunner ◽  
Joyce E. Meyerson ◽  
Alex Hall ◽  
Neil Berg
Keyword(s):  
Global Warming ◽  
Large Scale ◽  
Coupled Model ◽  
Precipitation Change ◽  
Storm Tracks ◽  
Scale Model ◽  
Model Intercomparison ◽  
California Coast ◽  
Considerable Uncertainty ◽  
Intercomparison Project

Abstract Projections of possible precipitation change in California under global warming have been subject to considerable uncertainty because California lies between the region anticipated to undergo increases in precipitation at mid-to-high latitudes and regions of anticipated decrease in the subtropics. Evaluation of the large-scale model experiments for phase 5 of the Coupled Model Intercomparison Project (CMIP5) suggests a greater degree of agreement on the sign of the winter (December–February) precipitation change than in the previous such intercomparison, indicating a greater portion of California falling within the increased precipitation zone. While the resolution of global models should not be relied on for accurate depiction of topographic rainfall distribution within California, the precipitation changes depend substantially on large-scale shifts in the storm tracks arriving at the coast. Significant precipitation increases in the region arriving at the California coast are associated with an eastward extension of the region of strong Pacific jet stream, which appears to be a robust feature of the large-scale simulated changes. This suggests that effects of this jet extension in steering storm tracks toward the California coast constitute an important factor that should be assessed for impacts on incoming storm properties for high-resolution regional model assessments.

scholarly journals Two Interglacials: Scientific Objectives and Experimental Designs for CMIP6 and PMIP4 Holocene and Last Interglacial Simulations

2016 ◽  
Author(s):  
Bette L. Otto-Bliesner ◽  
Pascale Braconnot ◽  
Sandy P. Harrison ◽  
Daniel J. Lunt ◽  
Ayako Abe-Ouchi ◽  
...  
Keyword(s):  
Land Surface ◽  
Radiative Forcing ◽  
Large Scale ◽  
Climate Changes ◽  
Systematic Evaluation ◽  
Before Present ◽  
Last Interglacial ◽  
Sensitivity Experiments ◽  
Intercomparison Project ◽  
The Impact

Abstract. Two interglacial epochs are included in the suite of paleoclimate simulations in the present phase of the Coupled Model Intercomparison Project (CMIP6). Equilibrium simulations of the mid-Holocene (midHolocene, 6000 years before present) and the Last Interglacial (lig127k, 127,000 years before present) are designed to examine the impact of changes in orbital forcing at times when atmospheric greenhouse gas levels were similar to those of the preindustrial period and the continental configurations were almost identical to modern. These simulations test our understanding of the interplay between radiative forcing and atmospheric circulation, and the connections among large-scale and regional climate changes giving rise to phenomena such as land-sea contrast and high-latitude amplification in temperature changes, and responses of the monsoons, as compared to today. They also provide an opportunity, through carefully designed additional sensitivity experiments as part of the Paleoclimate Modeling Intercomparison Project (PMIP4), to quantify the strength of atmosphere, ocean, cryosphere, and land-surface feedbacks. Sensitivity experiments are proposed to investigate the role of freshwater forcing in triggering abrupt climate changes within interglacial epochs. These feedback experiments naturally lead to a focus on climate evolution during interglacial periods, which will be examined through transient experiments. Analyses of the sensitivity simulations will also focus on interactions between extratropical and tropical circulation, and the relationship between changes in mean climate state and climate variability on annual to multi-decadal timescales. The comparative abundance of paleoenvironmental data and of quantitative climate reconstructions for the Holocene and Last Interglacial make these two epochs ideal candidates for systematic evaluation of model performance, and such comparisons will shed new light on the importance of external feedbacks (e.g., vegetation, dust) and the ability of state-of-the-art models to simulate climate changes realistically.

scholarly journals The PMIP4 contribution to CMIP6 – Part 2: Two interglacials, scientific objective and experimental design for Holocene and Last Interglacial simulations

2017 ◽  
Vol 10 (11) ◽  
pp. 3979-4003 ◽  
Author(s):  
Bette L. Otto-Bliesner ◽  
Pascale Braconnot ◽  
Sandy P. Harrison ◽  
Daniel J. Lunt ◽  
Ayako Abe-Ouchi ◽  
...  
Keyword(s):  
Land Surface ◽  
Radiative Forcing ◽  
Large Scale ◽  
Climate Changes ◽  
Systematic Evaluation ◽  
Before Present ◽  
Last Interglacial ◽  
Sensitivity Experiments ◽  
Intercomparison Project ◽  
The Impact

Abstract. Two interglacial epochs are included in the suite of Paleoclimate Modeling Intercomparison Project (PMIP4) simulations in the Coupled Model Intercomparison Project (CMIP6). The experimental protocols for simulations of the mid-Holocene (midHolocene, 6000 years before present) and the Last Interglacial (lig127k, 127 000 years before present) are described here. These equilibrium simulations are designed to examine the impact of changes in orbital forcing at times when atmospheric greenhouse gas levels were similar to those of the preindustrial period and the continental configurations were almost identical to modern ones. These simulations test our understanding of the interplay between radiative forcing and atmospheric circulation, and the connections among large-scale and regional climate changes giving rise to phenomena such as land–sea contrast and high-latitude amplification in temperature changes, and responses of the monsoons, as compared to today. They also provide an opportunity, through carefully designed additional sensitivity experiments, to quantify the strength of atmosphere, ocean, cryosphere, and land-surface feedbacks. Sensitivity experiments are proposed to investigate the role of freshwater forcing in triggering abrupt climate changes within interglacial epochs. These feedback experiments naturally lead to a focus on climate evolution during interglacial periods, which will be examined through transient experiments. Analyses of the sensitivity simulations will also focus on interactions between extratropical and tropical circulation, and the relationship between changes in mean climate state and climate variability on annual to multi-decadal timescales. The comparative abundance of paleoenvironmental data and of quantitative climate reconstructions for the Holocene and Last Interglacial make these two epochs ideal candidates for systematic evaluation of model performance, and such comparisons will shed new light on the importance of external feedbacks (e.g., vegetation, dust) and the ability of state-of-the-art models to simulate climate changes realistically.

scholarly journals The PMIP4 contribution to CMIP6 – Part 2: Two Interglacials, Scientific Objective and Experimental Design for Holocene and Last Interglacial Simulations

2016 ◽  
Author(s):  
Bette L. Otto-Bliesner ◽  
Pascale Braconnot ◽  
Sandy P. Harrison ◽  
Daniel J. Lunt ◽  
Ayako Abe-Ouchi ◽  
...  
Keyword(s):  
Land Surface ◽  
Radiative Forcing ◽  
Large Scale ◽  
Climate Changes ◽  
Systematic Evaluation ◽  
Before Present ◽  
Last Interglacial ◽  
Sensitivity Experiments ◽  
Intercomparison Project ◽  
The Impact

Abstract. Two interglacial epochs are included in the suite of Paleoclimate Modeling Intercomparison Project (PMIP4) simulations in the Coupled Model Intercomparison Project (CMIP6). The experimental protocols for Tier 1 simulations of the mid-Holocene (midHolocene, 6000 years before present) and the Last Interglacial (lig127k, 127,000 years before present) are described here. These equilibrium simulations are designed to examine the impact of changes in orbital forcing at times when atmospheric greenhouse gas levels were similar to those of the preindustrial period and the continental configurations were almost identical to modern. These simulations test our understanding of the interplay between radiative forcing and atmospheric circulation, and the connections among large-scale and regional climate changes giving rise to phenomena such as land-sea contrast and high-latitude amplification in temperature changes, and responses of the monsoons, as compared to today. They also provide an opportunity, through carefully designed additional CMIP6 Tier 2 and Tier 3 sensitivity experiments of PMIP4, to quantify the strength of atmosphere, ocean, cryosphere, and land-surface feedbacks. Sensitivity experiments are proposed to investigate the role of freshwater forcing in triggering abrupt climate changes within interglacial epochs. These feedback experiments naturally lead to a focus on climate evolution during interglacial periods, which will be examined through transient experiments. Analyses of the sensitivity simulations will also focus on interactions between extratropical and tropical circulation, and the relationship between changes in mean climate state and climate variability on annual to multi-decadal timescales. The comparative abundance of paleoenvironmental data and of quantitative climate reconstructions for the Holocene and Last Interglacial make these two epochs ideal candidates for systematic evaluation of model performance, and such comparisons will shed new light on the importance of external feedbacks (e.g., vegetation, dust) and the ability of state-of-the-art models to simulate climate changes realistically.

GFDL’s ESM2 Global Coupled Climate–Carbon Earth System Models. Part I: Physical Formulation and Baseline Simulation Characteristics

2012 ◽  
Vol 25 (19) ◽  
pp. 6646-6665 ◽  
Author(s):  
John P. Dunne ◽  
Jasmin G. John ◽  
Alistair J. Adcroft ◽  
Stephen M. Griffies ◽  
Robert W. Hallberg ◽  
...  
Keyword(s):  
Climate Changes ◽  
Southern Oscillation ◽  
Heat Content ◽  
Ocean Dynamics ◽  
Thermocline Depth ◽  
Earth System ◽  
System Models ◽  
Model Version ◽  
Earth System Models

Abstract The physical climate formulation and simulation characteristics of two new global coupled carbon–climate Earth System Models, ESM2M and ESM2G, are described. These models demonstrate similar climate fidelity as the Geophysical Fluid Dynamics Laboratory’s previous Climate Model version 2.1 (CM2.1) while incorporating explicit and consistent carbon dynamics. The two models differ exclusively in the physical ocean component; ESM2M uses Modular Ocean Model version 4p1 with vertical pressure layers while ESM2G uses Generalized Ocean Layer Dynamics with a bulk mixed layer and interior isopycnal layers. Differences in the ocean mean state include the thermocline depth being relatively deep in ESM2M and relatively shallow in ESM2G compared to observations. The crucial role of ocean dynamics on climate variability is highlighted in El Niño–Southern Oscillation being overly strong in ESM2M and overly weak in ESM2G relative to observations. Thus, while ESM2G might better represent climate changes relating to total heat content variability given its lack of long-term drift, gyre circulation, and ventilation in the North Pacific, tropical Atlantic, and Indian Oceans, and depth structure in the overturning and abyssal flows, ESM2M might better represent climate changes relating to surface circulation given its superior surface temperature, salinity, and height patterns, tropical Pacific circulation and variability, and Southern Ocean dynamics. The overall assessment is that neither model is fundamentally superior to the other, and that both models achieve sufficient fidelity to allow meaningful climate and earth system modeling applications. This affords the ability to assess the role of ocean configuration on earth system interactions in the context of two state-of-the-art coupled carbon–climate models.

scholarly journals A return to large-scale features of Pliocene climate: the Pliocene Model Intercomparison Project Phase 2

2020 ◽  
Author(s):  
Alan M. Haywood ◽  
Julia C. Tindall ◽  
Harry J. Dowsett ◽  
Aisling M. Dolan ◽  
Kevin M. Foley ◽  
...  
Keyword(s):  
Large Scale ◽  
Climate Models ◽  
Temperature Response ◽  
Surface Air Temperature ◽  
Co2 Concentration ◽  
Mean Value ◽  
System Response ◽  
Phase 2 ◽  
Model Intercomparison ◽  
Intercomparison Project

Abstract. The Pliocene epoch has great potential to improve our understanding of the long-term climatic and environmental consequences of an atmospheric CO2 concentration near ~ 400 parts per million by volume. Here we present the large-scale features of Pliocene climate as simulated by a new ensemble of climate models of varying complexity and spatial resolution and based on new reconstructions of boundary conditions (the Pliocene Model Intercomparison Project Phase 2; PlioMIP2). As a global annual average, modelled surface air temperatures increase by between 1.4 and 4.7 °C relative to pre-industrial with a multi-model mean value of 2.8 °C. Annual mean total precipitation rates increase by 6 % (range: 2 %–13 %). On average, surface air temperature (SAT) increases are 1.3 °C greater over the land than over the oceans, and there is a clear pattern of polar amplification with warming polewards of 60° N and 60° S exceeding the global mean warming by a factor of 2.4. In the Atlantic and Pacific Oceans, meridional temperature gradients are reduced, while tropical zonal gradients remain largely unchanged. Although there are some modelling constraints, there is a statistically significant relationship between a model's climate response associated with a doubling in CO2 (Equilibrium Climate Sensitivity; ECS) and its simulated Pliocene surface temperature response. The mean ensemble earth system response to doubling of CO2 (including ice sheet feedbacks) is approximately 50 % greater than ECS, consistent with results from the PlioMIP1 ensemble. Proxy-derived estimates of Pliocene sea-surface temperatures are used to assess model estimates of ECS and indicate a range in ECS from 2.5 to 4.3 °C. This result is in general accord with the range in ECS presented by previous IPCC Assessment Reports.

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