PMIP4/CMIP6 last interglacial simulations using three different versions of MIROC: importance of vegetation

2021 ◽  
Author(s):  
Ryouta O'ishi ◽  
Wing-Le Chan ◽  
Ayako Abe-Ouchi ◽  
Sam Sherriff-Tadano ◽  
Rumi Ohgaito ◽  
...  
Keyword(s):  
Feedback Mechanism ◽  
Climate Feedback ◽  
High Latitudes ◽  
Last Interglacial ◽  
Proxy Data ◽  
Area Index ◽  
Vegetation Feedback ◽  
Temperature Changes ◽  
Northern High Latitude ◽  
Series Of Experiments

<p>We carry out three sets of last interglacial (LIG) experiments, named lig127k, and of pre-industrial experiments, named piControl, both as part of PMIP4/CMIP6 using three versions of the MIROC model: MIROC4m, MIROC4m-LPJ, and MIROC-ES2L. The results are compared with reconstructions from climate proxy data. All models show summer warming over northern high-latitude land, reflecting the differences between the distributions of the LIG and present-day solar irradiance. Globally averaged temperature changes are −0.94 K (MIROC4m), −0.39 K (MIROC4m-LPJ), and −0.43 K (MIROC-ES2L).<br>Only MIROC4m-LPJ, which includes dynamical vegetation feedback from the change in vegetation distribution, shows annual mean warming signals at northern high latitudes, as indicated by proxy data. In contrast, the latest Earth system model (ESM) of MIROC, MIROC-ES2L, which considers only a partial vegetation effect through the leaf area index, shows no change or even annual cooling over large parts of the Northern Hemisphere. Results from the series of experiments show that the inclusion of full vegetation feedback is necessary for the reproduction of the strong annual warming over land at northern high latitudes. The LIG experimental results show that the warming predicted by models is still underestimated, even with dynamical vegetation, compared to reconstructions from proxy data, suggesting that further investigation and improvement to the climate feedback mechanism are needed.</p>

scholarly journals PMIP4/CMIP6 last interglacial simulations using three different versions of MIROC: importance of vegetation

2021 ◽  
Vol 17 (1) ◽  
pp. 21-36
Author(s):  
Ryouta O'ishi ◽  
Wing-Le Chan ◽  
Ayako Abe-Ouchi ◽  
Sam Sherriff-Tadano ◽  
Rumi Ohgaito ◽  
...  
Keyword(s):  
Feedback Mechanism ◽  
Climate Feedback ◽  
High Latitudes ◽  
Last Interglacial ◽  
Proxy Data ◽  
Area Index ◽  
Vegetation Feedback ◽  
Temperature Changes ◽  
Northern High Latitude ◽  
Series Of Experiments

Abstract. We carry out three sets of last interglacial (LIG) experiments, named lig127k, and of pre-industrial experiments, named piControl, both as part of PMIP4/CMIP6 using three versions of the MIROC model: MIROC4m, MIROC4m-LPJ, and MIROC-ES2L. The results are compared with reconstructions from climate proxy data. All models show summer warming over northern high-latitude land, reflecting the differences between the distributions of the LIG and present-day solar irradiance. Globally averaged temperature changes are −0.94 K (MIROC4m), −0.39 K (MIROC4m-LPJ), and −0.43 K (MIROC-ES2L). Only MIROC4m-LPJ, which includes dynamical vegetation feedback from the change in vegetation distribution, shows annual mean warming signals at northern high latitudes, as indicated by proxy data. In contrast, the latest Earth system model (ESM) of MIROC, MIROC-ES2L, which considers only a partial vegetation effect through the leaf area index, shows no change or even annual cooling over large parts of the Northern Hemisphere. Results from the series of experiments show that the inclusion of full vegetation feedback is necessary for the reproduction of the strong annual warming over land at northern high latitudes. The LIG experimental results show that the warming predicted by models is still underestimated, even with dynamical vegetation, compared to reconstructions from proxy data, suggesting that further investigation and improvement to the climate feedback mechanism are needed.

scholarly journals PMIP4/CMIP6 Last Interglacial simulations using different versions of MIROC, with and without vegetation feedback

2020 ◽  
Author(s):  
Ryouta O'ishi ◽  
Wing-Le Chan ◽  
Ayako Abe-Ouchi ◽  
Sam Sherriff-Tadano ◽  
Rumi Ohgaito
Keyword(s):  
Feedback Mechanism ◽  
Climate Feedback ◽  
High Latitudes ◽  
Last Interglacial ◽  
Proxy Data ◽  
Area Index ◽  
Vegetation Feedback ◽  
Summer Warming ◽  
Northern High Latitude ◽  
Series Of Experiments

Abstract. We carry out a Last Interglacial (LIG) experiment, named lig127k and a Tier1 experiment of PMIP4/CMIP6, using three versions of the MIROC model, MIROC4m, MIROC4m-LPJ and MIROC-ES2L. The results are compared with reconstructions from climate proxy data. All models show summer warming over northern high latitude land, reflecting the differences between the distributions of the LIG and present-day solar irradiance. Only MIROC4m-LPJ, which includes dynamical vegetation feedback from the change in vegetation distribution, shows warming signals, even for the annual mean, at northern high latitudes, as shown by proxy data. However, the latest Earth System Model (ESM) of MIROC, MIROC-ES2L, in which there is only a partial vegetation effect through the leaf area index, shows no change or even annual cooling over large parts of the northern hemisphere. Results from the series of experiments show that the inclusion of vegetation feedback is necessary for the reproduction of the strong annual warming over land at northern high latitudes. The LIG experimental results show that the warming predicted by models is still underestimated, even with dynamical vegetation, compared to reconstructions from proxy data, suggesting that further investigation and improvement to the climate feedback mechanism are needed.

scholarly journals The last interglacial (Eemian) climate simulated by LOVECLIM and CCSM3

2012 ◽  
Vol 8 (5) ◽  
pp. 5293-5340 ◽  
Author(s):  
I. Nikolova ◽  
Q. Yin ◽  
A. Berger ◽  
U. K. Singh ◽  
M. P. Karami
Keyword(s):  
Large Scale ◽  
Climate Models ◽  
Hydrological Cycle ◽  
The Arctic ◽  
Boreal Summer ◽  
Interglacial Period ◽  
Last Interglacial ◽  
Proxy Data ◽  
Vegetation Feedback ◽  
Depth Analysis

Abstract. This paper presents a detailed analysis of the climate of the last interglacial simulated by two climate models of different complexities, LOVECLIM and CCSM3. The simulated surface temperature, hydrological cycle, vegetation and ENSO variability during the last interglacial are analyzed through the comparison with the simulated Pre-Industrial (PI) climate. In both models, the last interglacial period is characterized by a significant warming (cooling) over almost all the continents during boreal summer (winter) leading to a largely increased (reduced) seasonal contrast in the northern (southern) hemisphere. This is mainly due to the much higher (lower) insolation received by the whole Earth in boreal summer (winter) during this interglacial. The arctic is warmer than PI through the whole year, resulting from its much higher summer insolation and its remnant effect in the following fall-winter through the interactions between atmosphere, ocean and sea ice. In the tropical Pacific, the change in the SST annual cycle is suggested to be related to a minor shift towards an El Nino, slightly stronger for MIS-5 than for PI. Intensified African monsoon and vegetation feedback are responsible for the cooling during summer in North Africa and Arabian Peninsula. Over India precipitation maximum is found further west, while in Africa the precipitation maximum migrates further north. Trees and grassland expand north in Sahel/Sahara. A mix of forest and grassland occupies continents and expand deep in the high northern latitudes. Desert areas reduce significantly in Northern Hemisphere, but increase in North Australia. The simulated large-scale climate change during the last interglacial compares reasonably well with proxy data, giving credit to both models and reconstructions. However, discrepancies exist at some regional scales between the two models, indicating the necessity of more in depth analysis of the models and comparisons with proxy data.

scholarly journals The Mutual Interaction between External Rossby Waves and Thermal Forcing: The Subpolar Regions

2010 ◽  
Vol 67 (6) ◽  
pp. 2018-2038 ◽  
Author(s):  
Isidoro Orlanski ◽  
Silvina Solman
Keyword(s):  
Large Amplitude ◽  
Diabatic Heating ◽  
Rossby Waves ◽  
Feedback Mechanism ◽  
High Latitudes ◽  
Thermal Forcing ◽  
Global Spectral Model ◽  
Meridional Velocity ◽  
Series Of Experiments ◽  
Simple Feedback

Abstract The authors hypothesize a simple feedback mechanism between external Rossby waves and diabatic heating from convection. This mechanism could explain the large amplitude that external Rossby waves attain as they propagate to mid- and high latitudes. A series of experiments has been carried out with a core dynamic global spectral model. These simulations with the idealized atmospheric GCM and a simple parameterization of thermal forcing proportional to the low-level wave meridional velocity suggest that external Rossby waves can be enhanced by convection, which they themselves induce. It is shown that in the tropospheric upper levels the amplitude of the external waves can be twice as large with feedback as for a control simulation that does not allow feedback.

scholarly journals Temporal and spatial structure of multi-millennial temperature changes at high latitudes during the Last Interglacial

2014 ◽  
Vol 103 ◽  
pp. 116-133 ◽  
Author(s):  
Emilie Capron ◽  
Aline Govin ◽  
Emma J. Stone ◽  
Valérie Masson-Delmotte ◽  
Stefan Mulitza ◽  
...  
Keyword(s):  
Spatial Structure ◽  
High Latitudes ◽  
Last Interglacial ◽  
Temperature Changes ◽  
Temporal And Spatial

scholarly journals Asymmetry and uncertainties in biogeophysical climate–vegetation feedback over a range of CO<sub>2</sub> forcings

2014 ◽  
Vol 11 (1) ◽  
pp. 17-32 ◽  
Author(s):  
M. Willeit ◽  
A. Ganopolski ◽  
G. Feulner
Keyword(s):  
Stomatal Conductance ◽  
Climate Feedback ◽  
Climate Feedbacks ◽  
Area Index ◽  
Vegetation Feedback ◽  
Northern Latitudes ◽  
Global Temperature Change ◽  
Dominant Process ◽  
Physics Ensemble ◽  
The Tropics

Abstract. Climate–vegetation feedback has the potential to significantly contribute to climate change, but little is known about its range of uncertainties. Here, using an Earth system model of intermediate complexity we address possible uncertainties in the strength of the biogeophysical climate–vegetation feedback using a single-model multi-physics ensemble. Equilibrium experiments with halving (140 ppm) and doubling (560 ppm) of CO2 give a contribution of the vegetation–climate feedback to global temperature change in the range −0.3 to −0.1 °C and −0.1 to 0.2 °C, respectively. There is an asymmetry between warming and cooling, with a larger, positive vegetation–climate feedback in the lower CO2 climate. Hotspots of climate–vegetation feedback are the boreal zone, the Amazon rainforest and the Sahara. Albedo parameterization is the dominant source of uncertainty in the subtropics and at high northern latitudes, while uncertainties in evapotranspiration are more relevant in the tropics. We analyse the separate impact of changes in stomatal conductance, leaf area index and vegetation dynamics on climate and we find that different processes are dominant in lower and higher CO2 worlds. The reduction in stomatal conductance gives the main contribution to temperature increase for a doubling of CO2, while dynamic vegetation is the dominant process in the CO2 halving experiments. Globally the climate–vegetation feedback is rather small compared to the sum of the fast climate feedbacks. However, it is comparable to the amplitude of the fast feedbacks at high northern latitudes where it can contribute considerably to polar amplification. The uncertainties in the climate–vegetation feedback are comparable to the multi-model spread of the fast climate feedbacks.

scholarly journals Asymmetry and uncertainties in biogeophysical climate–vegetation feedback over a range of CO<sub>2</sub> forcings

2013 ◽  
Vol 10 (8) ◽  
pp. 12967-13013 ◽  
Author(s):  
M. Willeit ◽  
A. Ganopolski ◽  
G. Feulner
Keyword(s):  
Stomatal Conductance ◽  
Climate Feedback ◽  
Single Model ◽  
Area Index ◽  
Vegetation Feedback ◽  
Northern Latitudes ◽  
Global Temperature Change ◽  
Dominant Process ◽  
Physics Ensemble ◽  
The Tropics

Abstract. Climate–vegetation feedback has the potential to significantly contribute to climate change, but little is known about its range of uncertainties. Here, using an Earth system model of intermediate complexity we address possible uncertainties in the strength of the biogeophysical climate–vegetation feedback using a single-model multi-physics ensemble. Equilibrium experiments with halving (140 ppm) and doubling (560 ppm) of CO2 give a contribution of the vegetation–climate feedback to global temperature change in the range −0.4 to −0.1 °C and −0.1–0.2 °C, respectively. There is an asymmetry between warming and cooling, with a larger, positive vegetation–climate feedback in the lower CO2 climate. Hotspots of climate–vegetation feedback are the boreal zone, the Amazon rainforest and the Sahara. Albedo parameterisation is the dominant source of uncertainty in the subtropics and at high northern latitudes, while uncertainties in evapotranspiration are more relevant in the tropics. Additionally we find that, even considering the upper range of uncertainties, globally the climate–vegetation feedback is rather small compared to the sum of the fast Charney feedbacks. However, it is comparable to the amplitude of the fast feedbacks at high northern latitudes where it can contribute considerably to polar amplification. Furthermore we analyse the separate impact of changes in stomatal conductance, leaf area index and vegetation dynamics on climate and we find that different processes are dominant in lower and higher CO2 worlds. The reduction in stomatal conductance gives the main contribution to temperature increase for a doubling of CO2, while dynamic vegetation is the dominant process in the CO2 halving experiments.

scholarly journals Northern high-latitude climate change between the mid and late Holocene – Part 1: Proxy data evidence

2009 ◽  
Vol 5 (4) ◽  
pp. 1819-1852 ◽  
Author(s):  
H. S. Sundqvist ◽  
Q. Zhang ◽  
A. Moberg ◽  
K. Holmgren ◽  
H. Körnich ◽  
...  
Keyword(s):  
Climate Model ◽  
Cold Season ◽  
High Latitudes ◽  
Proxy Data ◽  
Summer Insolation ◽  
Temperature And Precipitation ◽  
Northern High Latitude ◽  
Quantitative Understanding ◽  
Climate Model Simulations ◽  
Using Data

Abstract. In this paper we try to develop a quantitative understanding of the absolute change in climate between the mid-Holocene ~6000 yr BP (6 ka) and the preindustrial period ~1750 AD (0 ka) in the northern high latitudes. This has been performed using available quantitative reconstructions of temperature and precipitation from proxy data. The main reason for comparing these two periods is that the summer insolation in the northern high latitudes was higher at 6 ka than 0 ka due to orbital forcing. Another reason is that it gives us the opportunity to quantitatively compare results from proxy data with results from several climate model simulations for the same periods by using data from the Palaeoclimate Modelling Intercomparison Project. Another aim has been to try and quantify the uncertainties in the proxy data reconstructions. The reconstructions indicate that the northern high latitudes were 0.96±0.42°C warmer in summer, 1.71±1.70°C warmer in winter and 2.02±0.72 warmer in the annual mean temperature at 6 ka compared to 0 ka. The warmer climate in summer around 6 ka BP was most likely directly related to the higher summer insolation whereas the warmer climate in annual mean and winter temperature may possibly be explained by internal physical mechanisms such as heat stored in the oceans during summer and released during the cold season or by changes in the vegetation causing albedo changes that may affect seasonal temperatures differentially. For the future there is a great need to reduce the errors of the predictions as well as improving our understanding of how a proxys respond to changes in environmental variables.

scholarly journals CMIP6/PMIP4 simulations of the mid-Holocene and Last Interglacial using HadGEM3: comparison to the pre-industrial era, previous model versions and proxy data

2020 ◽  
Vol 16 (4) ◽  
pp. 1429-1450 ◽  
Author(s):  
Charles J. R. Williams ◽  
Maria-Vittoria Guarino ◽  
Emilie Capron ◽  
Irene Malmierca-Vallet ◽  
Joy S. Singarayer ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Climate Model ◽  
Geographical Location ◽  
West African Monsoon ◽  
Last Interglacial ◽  
Atmospheric Concentration ◽  
Industrial Control ◽  
Proxy Data ◽  
Orbital Configuration ◽  
The Uk

Abstract. Palaeoclimate model simulations are an important tool to improve our understanding of the mechanisms of climate change. These simulations also provide tests of the ability of models to simulate climates very different to today. Here we present the results from two brand-new simulations using the latest version of the UK's physical climate model, HadGEM3-GC3.1; they are the mid-Holocene (∼6 ka) and Last Interglacial (∼127 ka) simulations, both conducted under the auspices of CMIP6/PMIP4. This is the first time this version of the UK model has been used to conduct palaeoclimate simulations. These periods are of particular interest to PMIP4 because they represent the two most recent warm periods in Earth history, where atmospheric concentration of greenhouse gases and continental configuration are similar to the pre-industrial period but where there were significant changes to the Earth's orbital configuration, resulting in a very different seasonal cycle of radiative forcing. Results for these simulations are assessed firstly against the same model's pre-industrial control simulation (a simulation comparison, to describe and understand the differences between the pre-industrial – PI – and the two palaeo simulations) and secondly against previous versions of the same model relative to newly available proxy data (a model–data comparison, to compare all available simulations from the same model with proxy data to assess any improvements due to model advances). The introduction of this newly available proxy data adds further novelty to this study. Globally, for metrics such as 1.5 m temperature and surface rainfall, whilst both the recent palaeoclimate simulations are mostly capturing the expected sign and, in some places, magnitude of change relative to the pre-industrial, this is geographically and seasonally dependent. Compared to newly available proxy data (including sea surface temperature – SST – and rainfall) and also incorporating data from previous versions of the model shows that the relative accuracy of the simulations appears to vary according to metric, proxy reconstruction used for comparison and geographical location. In some instances, such as mean rainfall in the mid-Holocene, there is a clear and linear improvement, relative to proxy data, from the oldest to the newest generation of the model. When zooming into northern Africa, a region known to be problematic for models in terms of rainfall enhancement, the behaviour of the West African monsoon in both recent palaeoclimate simulations is consistent with current understanding, suggesting a wetter monsoon during the mid-Holocene and (more so) the Last Interglacial, relative to the pre-industrial era. However, regarding the well-documented “Saharan greening” during the mid-Holocene, results here suggest that the most recent version of the UK's physical model is still unable to reproduce the increases suggested by proxy data, consistent with all other previous models to date.

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