Author
Masa Kageyama
Bio: Masa Kageyama is an academic researcher from Université Paris-Saclay. The author has contributed to research in topics: Last Glacial Maximum & Climate model. The author has an hindex of 18, co-authored 45 publications receiving 1301 citations.
Papers
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Université Paris-Saclay1, University of Reading2, University of Leeds3, Max Planck Society4, Japan Agency for Marine-Earth Science and Technology5, University of Tokyo6, University of Cologne7, University of Oregon8, University College London9, Université catholique de Louvain10, Complutense University of Madrid11, University of Bern12, University of Bristol13, University of Birmingham14, University of Chile15, Cornell University16, University of Toronto17, University of Tasmania18, VU University Amsterdam19, Goddard Institute for Space Studies20, St. John's University21, Chinese Academy of Sciences22
TL;DR: In this paper, a series of GMD papers on the PMIP4-CMIP6 experiments are presented, with a focus on their novel features compared to the experiments performed in previous phases of PMIP and CMIP.
Abstract: . This paper is the first of a series of four GMD papers on the PMIP4-CMIP6 experiments. Part 2 (Otto-Bliesner et al., 2017) gives details about the two PMIP4-CMIP6 interglacial experiments, Part 3 (Jungclaus et al., 2017) about the last millennium experiment, and Part 4 (Kageyama et al., 2017) about the Last Glacial Maximum experiment. The mid-Pliocene Warm Period experiment is part of the Pliocene Model Intercomparison Project (PlioMIP) – Phase 2, detailed in Haywood et al. (2016). The goal of the Paleoclimate Modelling Intercomparison Project (PMIP) is to understand the response of the climate system to different climate forcings for documented climatic states very different from the present and historical climates. Through comparison with observations of the environmental impact of these climate changes, or with climate reconstructions based on physical, chemical, or biological records, PMIP also addresses the issue of how well state-of-the-art numerical models simulate climate change. Climate models are usually developed using the present and historical climates as references, but climate projections show that future climates will lie well outside these conditions. Palaeoclimates very different from these reference states therefore provide stringent tests for state-of-the-art models and a way to assess whether their sensitivity to forcings is compatible with palaeoclimatic evidence. Simulations of five different periods have been designed to address the objectives of the sixth phase of the Coupled Model Intercomparison Project (CMIP6): the millennium prior to the industrial epoch (CMIP6 name: past1000); the mid-Holocene, 6000 years ago (midHolocene); the Last Glacial Maximum, 21 000 years ago (lgm); the Last Interglacial, 127 000 years ago (lig127k); and the mid-Pliocene Warm Period, 3.2 million years ago (midPliocene-eoi400). These climatic periods are well documented by palaeoclimatic and palaeoenvironmental records, with climate and environmental changes relevant for the study and projection of future climate changes. This paper describes the motivation for the choice of these periods and the design of the numerical experiments and database requests, with a focus on their novel features compared to the experiments performed in previous phases of PMIP and CMIP. It also outlines the analysis plan that takes advantage of the comparisons of the results across periods and across CMIP6 in collaboration with other MIPs.
189 citations
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TL;DR: In this paper, a comparison between results from simulations of the Last Glacial Maximum climate and continental and surface ocean reconstructions for the North Atlantic, Europe and western Siberia is presented.
148 citations
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TL;DR: In this paper, the authors focus on the storm track representation in the models and its relationship with the surface temperatures, the mean flow, and the precipitation, and describe the storm tracks using transient eddy diagnostics such as mean sea level pressure variance and three-dimensional...
Abstract: Extratropical weather systems are an essential feature of the midlatitude climate and global circulation. At the last glacial maximum (LGM), the formation of regions of high transient activity, referred to as “storm tracks,” is strongly affected by the presence of large ice sheets over northern America and Scandinavia and by differences in sea surface temperature (SST) distributions. In the framework of the Palaeoclimate Modelling Intercomparison Project, simulations of the LGM climate have been run with a wide range of atmospheric general circulation models (AGCMs) using the same set of boundary conditions, allowing a valuable comparison between simulations of a climate very different from the present one. In this study, the authors focus on the storm track representation in the models and its relationship with the surface temperatures, the mean flow, and the precipitation. Storm tracks are described using transient eddy diagnostics such as mean sea level pressure variance and three-dimensional ...
144 citations
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Université Paris-Saclay1, University of Reading2, University of Bristol3, University of Leeds4, University of Toronto5, VU University Amsterdam6, Memorial University of Newfoundland7, Alfred Wegener Institute for Polar and Marine Research8, National Center for Atmospheric Research9, Cornell University10, Bjerknes Centre for Climate Research11, University of Oslo12, University College of Southeast Norway13, Stockholm University14, University of Tokyo15, University of Oregon16, Nanjing University of Information Science and Technology17, Japan Agency for Marine-Earth Science and Technology18, Russian Academy19, University of Hawaii at Manoa20, Nanjing University21
TL;DR: The last glacial maximum (LGM, 21,000 years ago) is one of the suite of paleoclimate simulations included in the current phase of the Coupled Model Intercomparison Project (CMIP6) as discussed by the authors.
Abstract: . The Last Glacial Maximum (LGM, 21 000 years ago) is one of the suite of paleoclimate simulations included in the current phase of the Coupled Model Intercomparison Project (CMIP6). It is an interval when insolation was similar to the present, but global ice volume was at a maximum, eustatic sea level was at or close to a minimum, greenhouse gas concentrations were lower, atmospheric aerosol loadings were higher than today, and vegetation and land-surface characteristics were different from today. The LGM has been a focus for the Paleoclimate Modelling Intercomparison Project (PMIP) since its inception, and thus many of the problems that might be associated with simulating such a radically different climate are well documented. The LGM state provides an ideal case study for evaluating climate model performance because the changes in forcing and temperature between the LGM and pre-industrial are of the same order of magnitude as those projected for the end of the 21st century. Thus, the CMIP6 LGM experiment could provide additional information that can be used to constrain estimates of climate sensitivity. The design of the Tier 1 LGM experiment (lgm) includes an assessment of uncertainties in boundary conditions, in particular through the use of different reconstructions of the ice sheets and of the change in dust forcing. Additional (Tier 2) sensitivity experiments have been designed to quantify feedbacks associated with land-surface changes and aerosol loadings, and to isolate the role of individual forcings. Model analysis and evaluation will capitalize on the relative abundance of paleoenvironmental observations and quantitative climate reconstructions already available for the LGM.
134 citations
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TL;DR: In this article, sea-surface conditions of the Last Glacial Maximum (LGM, 23-19-ka) were reconstructed using different proxies, which were calibrated to a standardized modern hydrography.
127 citations
Cited by
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Oeschger Centre for Climate Change Research1, Swiss Federal Institute of Aquatic Science and Technology2, University of Edinburgh3, Free University of Berlin4, ETH Zurich5, Université catholique de Louvain6, École Polytechnique7, University of Bristol8, Russian Academy of Sciences9, University of Birmingham10
TL;DR: The authors used selected proxy-based reconstructions of different climate variables, together with state-of-the-art time series of natural forcings (orbital variations, solar activity variations, large tropical volcanic eruptions, land cover and greenhouse gases), underpinned by results from GCMs and Earth System Models of Intermediate Complexity (EMICs), to establish a comprehensive explanatory framework for climate changes from the mid-Holocene (MH) to pre-industrial time.
1,539 citations
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TL;DR: A copy of the Guangbo jiemu bao [Broadcast Program Report] was being passed from hand to hand among a group of young people eager to be the first to read the article introducing the program "What Is Revolutionary Love?".
Abstract: A copy of Guangbo jiemu bao [Broadcast Program Report] was being passed from hand to hand among a group of young people eager to be the first to read the article introducing the program "What Is Revolutionary Love?" It said: "… Young friends, you are certainly very concerned about this problem'. So, we would like you to meet the young women workers Meng Xiaoyu and Meng Yamei and the older cadre Miss Feng. They are the three leading characters in the short story ‘The Place of Love.’ Through the description of the love lives of these three, the story induces us to think deeply about two questions that merit further examination.
1,528 citations
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TL;DR: This article presented the global general circulation model IPSL-CM5 developed to study the long-term response of the climate system to natural and anthropogenic forcings as part of the 5th Phase of the Coupled Model Intercomparison Project (CMIP5).
Abstract: We present the global general circulation model IPSL-CM5 developed to study the long-term response of the climate system to natural and anthropogenic forcings as part of the 5th Phase of the Coupled Model Intercomparison Project (CMIP5). This model includes an interactive carbon cycle, a representation of tropospheric and stratospheric chemistry, and a comprehensive representation of aerosols. As it represents the principal dynamical, physical, and bio-geochemical processes relevant to the climate system, it may be referred to as an Earth System Model. However, the IPSL-CM5 model may be used in a multitude of configurations associated with different boundary conditions and with a range of complexities in terms of processes and interactions. This paper presents an overview of the different model components and explains how they were coupled and used to simulate historical climate changes over the past 150 years and different scenarios of future climate change. A single version of the IPSL-CM5 model (IPSL-CM5A-LR) was used to provide climate projections associated with different socio-economic scenarios, including the different Representative Concentration Pathways considered by CMIP5 and several scenarios from the Special Report on Emission Scenarios considered by CMIP3. Results suggest that the magnitude of global warming projections primarily depends on the socio-economic scenario considered, that there is potential for an aggressive mitigation policy to limit global warming to about two degrees, and that the behavior of some components of the climate system such as the Arctic sea ice and the Atlantic Meridional Overturning Circulation may change drastically by the end of the twenty-first century in the case of a no climate policy scenario. Although the magnitude of regional temperature and precipitation changes depends fairly linearly on the magnitude of the projected global warming (and thus on the scenario considered), the geographical pattern of these changes is strikingly similar for the different scenarios. The representation of atmospheric physical processes in the model is shown to strongly influence the simulated climate variability and both the magnitude and pattern of the projected climate changes.
1,526 citations
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TL;DR: In this paper, a set of coupled ocean-atmosphere simulations using state-of-the-art climate models is presented for the Last Glacial Maximum and the Mid-Holocene through the second phase of the Paleoclimate Modeling Intercomparison Project (PMIP2).
Abstract: . A set of coupled ocean-atmosphere simulations using state of the art climate models is now available for the Last Glacial Maximum and the Mid-Holocene through the second phase of the Paleoclimate Modeling Intercomparison Project (PMIP2). This study presents the large-scale features of the simulated climates and compares the new model results to those of the atmospheric models from the first phase of the PMIP, for which sea surface temperature was prescribed or computed using simple slab ocean formulations. We consider the large-scale features of the climate change, pointing out some of the major differences between the different sets of experiments. We show in particular that systematic differences between PMIP1 and PMIP2 simulations are due to the interactive ocean, such as the amplification of the African monsoon at the Mid-Holocene or the change in precipitation in mid-latitudes at the LGM. Also the PMIP2 simulations are in general in better agreement with data than PMIP1 simulations.
1,170 citations
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TL;DR: The Palaeoclimate Modelling Intercomparison Project (POMIP) as discussed by the authors evaluated model performance against the geologic record of environmental responses to climate changes and provided a unique opportunity to test model performance outside this limited climate range.
Abstract: There is large uncertainty about the magnitude of warming and how rainfall patterns will change in response to any given scenario of future changes in atmospheric composition and land use. The models used for future climate projections were developed and calibrated using climate observations from the past 40 years. The geologic record of environmental responses to climate changes provides a unique opportunity to test model performance outside this limited climate range. Evaluation of model simulations against palaeodata shows that models reproduce the direction and large-scale patterns of past changes in climate, but tend to underestimate the magnitude of regional changes. As part of the effort to reduce model-related uncertainty and produce more reliable estimates of twenty-first century climate, the Palaeoclimate Modelling Intercomparison Project is systematically applying palaeoevaluation techniques to simulations of the past run with the models used to make future projections. This evaluation will provide assessments of model performance, including whether a model is sufficiently sensitive to changes in atmospheric composition, as well as providing estimates of the strength of biosphere and other feedbacks that could amplify the model response to these changes and modify the characteristics of climate variability.
852 citations