Mid-Holocene drylands: A multi-model analysis using Paleoclimate Modelling Intercomparison Project Phase III (PMIP3) simulations

The Holocene ◽  
2019 ◽  
Vol 29 (9) ◽  
pp. 1425-1438
Author(s):  
Shanshan Liu ◽  
Dabang Jiang ◽  
Xianmei Lang
Keyword(s):  
Relative Humidity ◽  
Potential Evapotranspiration ◽  
Aridity Index ◽  
Phase Iii ◽  
Collective Effects ◽  
Model Data ◽  
Intercomparison Project ◽  
The Difference ◽  
Paleoclimate Modelling Intercomparison Project ◽  
Paleoclimate Modelling

This study examines changes in aridity levels during the mid-Holocene (approximately 6000 cal. yr ago) using multi-model simulations from the Paleoclimate Modelling Intercomparison Project Phase III. Overall, there is little difference in the total area of drylands from the preindustrial period; global drylands are 8% wetter than during the preindustrial period as measured by an aridity index; and 16% of preindustrial drylands convert to a wetter climate subtype, double the sum of zones that are replaced by a drier category. Considerable variations are present among regions with major contractions of each dryland subtype from northern Africa to South Asia and the main expansions of arid, semiarid, and dry subhumid climates in southern hemisphere continents. The difference in precipitation is the leading factor of the aforementioned changes. The second factor is the altered potential evapotranspiration as mainly induced by relative humidity, which contributes to additional aridity changes in a same direction as precipitation does. The collective effects of precipitation and relative humidity account for more than 80% of the dryland variations. In comparison, the simulated aridity change is in reasonable agreement with reconstructions, while there are model–data discrepancies for Australia and uncertainties across proxies for southern Africa.

scholarly journals Climate forcing reconstructions for use in PMIP simulations of the last millennium (v1.0)

2011 ◽  
Vol 4 (1) ◽  
pp. 33-45 ◽  
Author(s):  
G. A. Schmidt ◽  
J. H. Jungclaus ◽  
C. M. Ammann ◽  
E. Bard ◽  
P. Braconnot ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Climate Forcing ◽  
Last Millennium ◽  
Land Use Land Cover ◽  
The Third ◽  
Third Phase ◽  
Intercomparison Project ◽  
Paleoclimate Modelling Intercomparison Project ◽  
Paleoclimate Modelling

Abstract. Simulations of climate over the Last Millennium (850–1850 CE) have been incorporated into the third phase of the Paleoclimate Modelling Intercomparison Project (PMIP3). The drivers of climate over this period are chiefly orbital, solar, volcanic, changes in land use/land cover and some variation in greenhouse gas levels. While some of these effects can be easily defined, the reconstructions of solar, volcanic and land use-related forcing are more uncertain. We describe here the approach taken in defining the scenarios used in PMIP3, document the forcing reconstructions and discuss likely implications.

scholarly journals The penultimate deglaciation: protocol for Paleoclimate Modelling Intercomparison Project (PMIP) phase 4 transient numerical simulations between 140 and 127 ka, version 1.0

2019 ◽  
Vol 12 (8) ◽  
pp. 3649-3685 ◽  
Author(s):  
Laurie Menviel ◽  
Emilie Capron ◽  
Aline Govin ◽  
Andrea Dutton ◽  
Lev Tarasov ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Working Group ◽  
Ice Sheets ◽  
Last Deglaciation ◽  
Transient Simulations ◽  
Intercomparison Project ◽  
The Last Deglaciation ◽  
Continental Ice Sheets ◽  
Paleoclimate Modelling Intercomparison Project ◽  
Paleoclimate Modelling

Abstract. The penultimate deglaciation (PDG, ∼138–128 thousand years before present, hereafter ka) is the transition from the penultimate glacial maximum (PGM) to the Last Interglacial (LIG, ∼129–116 ka). The LIG stands out as one of the warmest interglacials of the last 800 000 years (hereafter kyr), with high-latitude temperature warmer than today and global sea level likely higher by at least 6 m. Considering the transient nature of the Earth system, the LIG climate and ice-sheet evolution were certainly influenced by the changes occurring during the penultimate deglaciation. It is thus important to investigate, with coupled atmosphere–ocean general circulation models (AOGCMs), the climate and environmental response to the large changes in boundary conditions (i.e. orbital configuration, atmospheric greenhouse gas concentrations, ice-sheet geometry and associated meltwater fluxes) occurring during the penultimate deglaciation. A deglaciation working group has recently been set up as part of the Paleoclimate Modelling Intercomparison Project (PMIP) phase 4, with a protocol to perform transient simulations of the last deglaciation (19–11 ka; although the protocol covers 26–0 ka). Similar to the last deglaciation, the disintegration of continental ice sheets during the penultimate deglaciation led to significant changes in the oceanic circulation during Heinrich Stadial 11 (∼136–129 ka). However, the two deglaciations bear significant differences in magnitude and temporal evolution of climate and environmental changes. Here, as part of the Past Global Changes (PAGES)-PMIP working group on Quaternary interglacials (QUIGS), we propose a protocol to perform transient simulations of the penultimate deglaciation under the auspices of PMIP4. This design includes time-varying changes in orbital forcing, greenhouse gas concentrations, continental ice sheets as well as freshwater input from the disintegration of continental ice sheets. This experiment is designed for AOGCMs to assess the coupled response of the climate system to all forcings. Additional sensitivity experiments are proposed to evaluate the response to each forcing. Finally, a selection of paleo-records representing different parts of the climate system is presented, providing an appropriate benchmark for upcoming model–data comparisons across the penultimate deglaciation.

scholarly journals Second phase of paleoclimate modelling intercomparison project

Eos ◽  
2005 ◽  
Vol 86 (28) ◽  
pp. 264 ◽  
Author(s):  
M. Crucifix ◽  
P. Braconnot ◽  
S. P. Harrison ◽  
B. Otto-Bliesner
Keyword(s):  
Second Phase ◽  
Intercomparison Project ◽  
Paleoclimate Modelling Intercomparison Project ◽  
Paleoclimate Modelling

scholarly journals Modeling and Data Syntheses of Past Climates: Paleoclimate Modelling Intercomparison Project Phase II Workshop; Estes Park, Colorado, 15–19 September 2008

Eos ◽  
2009 ◽  
Vol 90 (11) ◽  
pp. 93 ◽  
Author(s):  
Bette L. Otto-Bliesner ◽  
Sylvie Joussaume ◽  
Pascale Braconnot ◽  
Sandy P. Harrison ◽  
Ayako Abe-Ouchi
Keyword(s):  
Phase Ii ◽  
Intercomparison Project ◽  
Paleoclimate Modelling Intercomparison Project ◽  
Paleoclimate Modelling

scholarly journals Análise das Simulações do PMIP3 Sobre o Nordeste Brasileiro Para o Período Pré-Industrial e Holoceno Médio

2019 ◽  
Vol 34 (1) ◽  
pp. 109-119
Author(s):  
Tyhago Aragão Dias ◽  
Alexandre Araújo Costa ◽  
Francisco de Assis Sousa Filho ◽  
Cleiton da Silva Silveira
Keyword(s):  
Climate Prediction ◽  
Phase Iiii ◽  
Intercomparison Project ◽  
Climate Prediction Center ◽  
Paleoclimate Modelling Intercomparison Project ◽  
Paleoclimate Modelling

Resumo Este trabalho mostra uma analise das simulações obtidas no banco de dados do PMIP3 (Paleoclimate Modelling Intercomparison Project Phase IIII) para o período pré-industrial com os dados observados pelo CMAP (Climate Prediction Center Merged Analysis of Precipitation) e Climatic Reserch Unit (CRU) para a precipitação pluviométrica em mm/mês e os dados de reanálise do NCEP/NCAR para a temperatura do ar a 2 m acima da superfície em graus Celsius, para as região do Nordeste Brasileiro (NEB) (46° W - 34° W; 16° S - 2° S), a fim de encontrar um conjunto de modelos com representação realista do clima do presente. Em seguida, uma comparação é feita entre os resultados das simulações desses modelos para o período pré-industrial (PI) e o Holoceno médio (HM, ~6.000 anos atrás), a fim de identificar possíveis mudanças climáticas entre esses períodos sobre a América do Sul. Esses modelos do PMIP3 sugerem que houve diferenças importantes entre o clima atual e o do Holoceno Médio no que diz respeito à intensidade da monção da América do Sul (monção mais fraca no HM do que no presente).

scholarly journals Arctic sea ice in the mid-Holocene Paleoclimate Modelling Intercomparison Project 2 simulations

2012 ◽  
Vol 8 (4) ◽  
pp. 3445-3480
Author(s):  
M. Berger ◽  
J. Brandefelt ◽  
J. Nilsson
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Solar Insolation ◽  
Sea Ice Extent ◽  
Arctic Sea ◽  
Intercomparison Project ◽  
The Mean ◽  
The Difference ◽  
Mean State ◽  
Paleoclimate Modelling

Abstract. The Arctic sea ice in the mid-Holocene simulations of 11 coupled global circulation models part of the Paleoclimate Modelling Intercomparison Project phase 2 (PMIP2) is analysed in this study. The work includes a comparison of the mid-Holocene simulations to the pre-industrial control simulations for each individual model and also a model-model comparison. The forcing conditions in the mid-Holocene and pre-industrial simulations differ in the atmospheric methane concentration and the latitudinal and monthly distribution of solar insolation (due to differences in the orbital parameters). Other studies have found that the difference in insolation, with increased northern hemisphere summer insolation, explain the major differences between the simulated mid-Holocene and pre-industrial climates. The response of the simulated sea ice extent and thickness to the changes in solar insolation and atmospheric greenhouse gases is investigated. The model-model variation in pre-industrial simulated Arctic sea ice is large, with sea ice area extent ranging from 10.1 to 28.2 (7.01 to 24.6) million km2 in March (September), and the maximum sea ice thickness ranging from 1.5 m to more than 5 m in both September and March. Nevertheless, all models agree on the sign of the difference between mid-Holocene and pre-industrial in both March and September. All models have smaller summer sea ice extent and thinner ice cover in all seasons in the mid-Holocene climate compared to the control (pre-industrial) climate. The reduction in sea ice extent is mostly confined to the sea ice margins, whereas the thinning of the ice occurs over the entire ice cover. In addition, the models also experience an enhanced summer warming north of 60° N. For the central Arctic region, models with thicker ice in the mean state in the control simulation experience the largest change in the mean state between the two climates. Comparison to available Climate Model Intercomparison Project 3 (CMIP3) simulations with the same model version and atmospheric CO2 concentration increased to a doubling has also been performed. The sea ice response in this future scenario is stronger than the response in the mid-Holocene simulation. Again we find that the model with the thickest mean state has the largest response.

scholarly journals Climate forcing reconstructions for use in PMIP simulations of the last millennium (v1.0)

2010 ◽  
Vol 3 (3) ◽  
pp. 1549-1586 ◽  
Author(s):  
G. A. Schmidt ◽  
J. H. Jungclaus ◽  
C. M. Ammann ◽  
E. Bard ◽  
P. Braconnot ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Climate Forcing ◽  
Last Millennium ◽  
Land Use Land Cover ◽  
The Third ◽  
Third Phase ◽  
Intercomparison Project ◽  
Paleoclimate Modelling Intercomparison Project ◽  
Paleoclimate Modelling

Abstract. Simulations of climate over the Last Millennium (850–1850 CE) have been incorporated into the third phase of the Paleoclimate Modelling Intercomparison Project (PMIP3). The drivers of climate over this period are chiefly orbital, solar, volcanic, changes in land use/land cover and some variation in greenhouse gas levels. While some of these effects can be easily defined, the reconstructions of solar, volcanic and land use-related forcing are more uncertain. We describe here the approach taken in defining the scenarios used in PMIP3, document the forcing reconstructions and discuss likely implications.

scholarly journals Estudo comparativo de simulações paleoclimáticas na região do Atlântico Sul

2007 ◽  
Vol 22 (1) ◽  
pp. 21-37
Author(s):  
Adriana Oliveira ◽  
Gagriel Clauzet ◽  
Ilana Wainer
Keyword(s):  
Climate System ◽  
System Model ◽  
Climate System Model ◽  
Atmospheric Research ◽  
Intercomparison Project ◽  
Paleoclimate Modelling Intercomparison Project ◽  
Paleoclimate Modelling

Neste estudo são comparadas diferentes simulações de modelos paleoclimáticos para duas épocas distintas, o Último Máximo Glacial (UMG) e o Presente. Esta comparação visa elucidar as principais diferenças nos processos físicos e dinâmicos do sistema oceano-atmosfera na região do oceano Atlântico Sul entre estes dois períodos. Foram analisadas as variações na climatologia anual entre estas épocas para os seguintes parâmetros: temperatura do ar (TA), precipitação (PPT) e pressão ao nível do mar (PNM). As simulações numéricas analisadas são do projeto PMIP (Paleoclimate Modelling Intercomparison Project) e do modelo numérico acoplado NCAR (National Center for Atmospheric Research) CCSM (Comunnity Climate System Model) versão 1.4 nos dois períodos de interesse. Os resultados mostram uma intensificação do presente em relação ao UMG em todas as variáveis analisadas. As diferentes simulações atmosféricas do PMIP apresentaram padrões consistentes com os apresentados no modelo NCAR CCSM, sendo observados baixos valores de EQM (Erro Quadrático Médio) para grande parte da região de estudo.

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