scholarly journals Overview of the Global Monsoons Model Inter-comparison Project (GMMIP)

2016 ◽  
Author(s):  
Tianjun Zhou ◽  
Andrew Turner ◽  
James Kinter ◽  
Bin Wang ◽  
Yun Qian ◽  
...  
Keyword(s):  
Coupled Model ◽  
Research Programme ◽  
Atlantic Multidecadal Oscillation ◽  
Interdecadal Pacific Oscillation ◽  
Fundamental Physics ◽  
Historical Simulation ◽  
The Past ◽  
External Forcings ◽  
Current Century ◽  
Scientific Questions

Abstract. The Global Monsoons Model Inter-comparison Project (GMMIP) has been endorsed by the panel of Coupled Model Inter-comparison Project (CMIP) as one of the participating MIPs in the sixth phase of CMIP (CMIP6). The focus of GMMIP is on monsoon climatology, variability, prediction and projection, which is relevant to four of the "Grand Challenges" proposed by the World Climate Research Programme. At present, 21 international modelling groups are committed to joining GMMIP. This overview paper introduces the motivation behind GMMIP and the scientific questions it intends to answer. Three tiers of experiments, of decreasing priority, are designed to examine: (a) model skill in simulating the climatology and interannual-to-multidecadal variability of global monsoons during SST-forced experiments of the historical climate period; (b) the roles of the Interdecadal Pacific Oscillation and Atlantic Multidecadal Oscillation in driving variations of the global and regional monsoons; and (c) the effects of large orographic terrain on the establishment of the monsoons. The outputs of the CMIP6 DECK, "historical" simulation and other MIPs will also be used in the diagnostic analysis of GMMIP to give a comprehensive understanding of the roles played by different external forcings, potential improvements in the simulation of monsoon rainfall at high resolution and predictability at decadal time scales. The implementation of GMMIP will improve our understanding of the fundamental physics of changes in the global and regional monsoons over the past 140 years and ultimately benefit monsoon prediction and projection in the current century.

scholarly journals GMMIP (v1.0) contribution to CMIP6: Global Monsoons Model Inter-comparison Project

2016 ◽  
Vol 9 (10) ◽  
pp. 3589-3604 ◽  
Author(s):  
Tianjun Zhou ◽  
Andrew G. Turner ◽  
James L. Kinter ◽  
Bin Wang ◽  
Yun Qian ◽  
...  
Keyword(s):  
Coupled Model ◽  
Research Programme ◽  
Atlantic Multidecadal Oscillation ◽  
Fundamental Physics ◽  
Historical Simulation ◽  
The Past ◽  
External Forcings ◽  
Current Century ◽  
Scientific Questions

Abstract. The Global Monsoons Model Inter-comparison Project (GMMIP) has been endorsed by the panel of Coupled Model Inter-comparison Project (CMIP) as one of the participating model inter-comparison projects (MIPs) in the sixth phase of CMIP (CMIP6). The focus of GMMIP is on monsoon climatology, variability, prediction and projection, which is relevant to four of the “Grand Challenges” proposed by the World Climate Research Programme. At present, 21 international modeling groups are committed to joining GMMIP. This overview paper introduces the motivation behind GMMIP and the scientific questions it intends to answer. Three tiers of experiments, of decreasing priority, are designed to examine (a) model skill in simulating the climatology and interannual-to-multidecadal variability of global monsoons forced by the sea surface temperature during historical climate period; (b) the roles of the Interdecadal Pacific Oscillation and Atlantic Multidecadal Oscillation in driving variations of the global and regional monsoons; and (c) the effects of large orographic terrain on the establishment of the monsoons. The outputs of the CMIP6 Diagnostic, Evaluation and Characterization of Klima experiments (DECK), “historical” simulation and endorsed MIPs will also be used in the diagnostic analysis of GMMIP to give a comprehensive understanding of the roles played by different external forcings, potential improvements in the simulation of monsoon rainfall at high resolution and reproducibility at decadal timescales. The implementation of GMMIP will improve our understanding of the fundamental physics of changes in the global and regional monsoons over the past 140 years and ultimately benefit monsoons prediction and projection in the current century.

Anthropogenic and Natural Contributions to the Lengthening of the Summer Season in the Northern Hemisphere

2018 ◽  
Vol 31 (17) ◽  
pp. 6803-6819 ◽  
Author(s):  
Bo-Joung Park ◽  
Yeon-Hee Kim ◽  
Seung-Ki Min ◽  
Eun-Pa Lim
Keyword(s):  
Northern Hemisphere ◽  
Coupled Model ◽  
Atlantic Multidecadal Oscillation ◽  
Summer Season ◽  
Season Length ◽  
The Past ◽  
External Forcings ◽  
Regional Trends ◽  
Intercomparison Project

Observed long-term variations in summer season timing and length in the Northern Hemisphere (NH) continents and their subregions were analyzed using temperature-based indices. The climatological mean showed coastal–inland contrast; summer starts and ends earlier inland than in coastal areas because of differences in heat capacity. Observations for the past 60 years (1953–2012) show lengthening of the summer season with earlier summer onset and delayed summer withdrawal across the NH. The summer onset advance contributed more to the observed increase in summer season length in many regions than the delay of summer withdrawal. To understand anthropogenic and natural contributions to the observed change, summer season trends from phase 5 of the Coupled Model Intercomparison Project (CMIP5) multimodel simulations forced with the observed external forcings [anthropogenic plus natural forcing (ALL), natural forcing only (NAT), and greenhouse gas forcing only (GHG)] were analyzed. ALL and GHG simulations were found to reproduce the overall observed global and regional lengthening trends, but NAT had negligible trends, which implies that increased greenhouse gases were the main cause of the observed changes. However, ALL runs tend to underestimate the observed trend of summer onset and overestimate that of withdrawal, the causes of which remain to be determined. Possible contributions of multidecadal variabilities, such as Pacific decadal oscillation and Atlantic multidecadal oscillation, to the observed regional trends in summer season length were also assessed. The results suggest that multidecadal variability can explain a moderate portion (about ±10%) of the observed trends in summer season length, mainly over the high latitudes.

scholarly journals Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP6) experimental design and organisation

2015 ◽  
Vol 8 (12) ◽  
pp. 10539-10583 ◽  
Author(s):  
V. Eyring ◽  
S. Bony ◽  
G. A. Meehl ◽  
C. Senior ◽  
B. Stevens ◽  
...  
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Coupled Model ◽  
Research Programme ◽  
Future Climate ◽  
Model Intercomparison ◽  
Historical Simulation ◽  
Intercomparison Project

Abstract. By coordinating the design and distribution of global climate model simulations of the past, current and future climate, the Coupled Model Intercomparison Project (CMIP) has become one of the foundational elements of climate science. However, the need to address an ever-expanding range of scientific questions arising from more and more research communities has made it necessary to revise the organization of CMIP. After a long and wide community consultation, a new and more federated structure has been put in place. It consists of three major elements: (1) a handful of common experiments, the DECK (Diagnostic, Evaluation and Characterization of Klima experiments) and the CMIP Historical Simulation (1850–near-present) that will maintain continuity and help document basic characteristics of models across different phases of CMIP, (2) common standards, coordination, infrastructure and documentation that will facilitate the distribution of model outputs and the characterization of the model ensemble, and (3) an ensemble of CMIP-Endorsed Model Intercomparison Projects (MIPs) that will be specific to a particular phase of CMIP (now CMIP6) and that will build on the DECK and the CMIP Historical Simulation to address a large range of specific questions and fill the scientific gaps of the previous CMIP phases. The DECK and CMIP Historical Simulation, together with the use of CMIP data standards, will be the entry cards for models participating in CMIP. The participation in the CMIP6-Endorsed MIPs will be at the discretion of the modelling groups, and will depend on scientific interests and priorities. With the Grand Science Challenges of the World Climate Research Programme (WCRP) as its scientific backdrop, CMIP6 will address three broad questions: (i) how does the Earth system respond to forcing?, (ii) what are the origins and consequences of systematic model biases?, and (iii) how can we assess future climate changes given climate variability, predictability and uncertainties in scenarios? This CMIP6 overview paper presents the background and rationale for the new structure of CMIP, provides a detailed description of the DECK and the CMIP6 Historical Simulation, and includes a brief introduction to the 21 CMIP6-Endorsed MIPs.

The Indian Ocean Dipole response to external forcing in coupled model intercomparison project phase 5 simulations of the last millennium

The Holocene ◽  
2021 ◽  
pp. 095968362098803
Author(s):  
Thanh Le ◽  
Deg-Hyo Bae
Keyword(s):  
Radiative Forcing ◽  
Coupled Model ◽  
Volcanic Eruptions ◽  
External Forcing ◽  
Solar Forcing ◽  
The Past ◽  
External Forcings ◽  
Intercomparison Project ◽  
The Indian Ocean ◽  
Past 1000 Years

The Indian Ocean Dipole (IOD) is a major mode of interannual climate variability, but its response to external climate forcings (i.e. solar forcing, volcanic radiative forcing (VRF) and greenhouse gas (GHG) radiative forcing) remains elusive. To improve our understanding of the variability of the IOD, it is necessary to investigate the IOD’s response to external forcings through multi-model simulations. Here a Granger causality test is used to examine the impact of external forcings on the IOD from past 1000 years simulations (850–1850 Common Era) derived from Coupled Model Intercomparison Project Phase 5 (CMIP5) models. The results show significant causal effects of VRF on the IOD in preindustrial times of the past 1000 years from the MPI-ESM-P, MRI-CGCM3, GISS-E2-R and CCSM4 models and uncertainties in the IOD’s responses to volcanic eruptions from other six models. Additionally, the phase responses (i.e. positive or negative) of the IOD to large volcanic eruptions remain unclear even from models showing significant causal impacts of VRF on the IOD. This result shows that the IOD exhibits a more complex response to volcanic forcing than the El Niño-Southern Oscillation. The causal impact of solar forcing on the IOD is more likely to be weak in most models. The IOD’s response to GHG variations is not significant across all the models due to minor fluctuations in GHGs occurring during preindustrial times of the past 1000 years. Further analyses based on new, improved and higher resolution models might further our understanding of the IOD’s responses to external forcing.

scholarly journals Climate Transition from Warm-Dry to Warm-Wet in Eastern Northwest China

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 548
Author(s):  
Jinhu Yang ◽  
Qiang Zhang ◽  
Guoyang Lu ◽  
Xiaoyun Liu ◽  
Youheng Wang ◽  
...  
Keyword(s):  
Temperature Change ◽  
Water Resource Management ◽  
Yellow River ◽  
Asian Summer Monsoon ◽  
Coupled Model ◽  
Research Programme ◽  
Northwest China ◽  
Humid Climate ◽  
Synergistic Enhancement ◽  
Climate Transition

During the second half of the 20th century, eastern Northwest China experienced a warming and drying climate change. To determine whether this trend has continued or changed during the present century, this study systematically analyzes the characteristics of warming and dry–wet changes in eastern Northwest China based on the latest observational data and World Climate Research Programme (WCRP) Coupled Model Intercomparison Project Phase 6 (CMIP6) collection data. The results show that eastern Northwest China has warmed continuously during the past 60 years with a sudden temperature change occurring in the late 1990s. However, the temperature in the 2000s decreased slowly, and that in the 2010s showed a warming trend. The amount of precipitation began to increase in the late 1990s, which indicates a contemporary climate transition from warm-dry to warm-wet in eastern Northwest China. The contribution of precipitation to humidity is significantly more than that of temperature. Long-term and interannual variations dominate the temperature change, with the contribution of the former much stronger than that of the latter. However, interannual variation dominates the precipitation change. The warming accelerates from period to period, and the temperature spatial consistently increased during the three most recent climatic periods. The precipitation decreased from 1961–1990 to 1981–2010, whereas its spatial consistency increased from 1981–2010 to 1991–2019. The significant warming and humidification which began in the late 1990s and is expected to continue until the end of the 21st century in the medium emission scenario. However, the current sub-humid climate will not easily be changed. The warming could cause a climate transition from warm temperate to subtropical by 2040. The dry-to-wet climate transition in eastern Northwest China could be related to a synergistic enhancement of the East Asian summer monsoon and the westerly circulation. This research provides a scientific decision-making basis for implementing western development strategies, ecological protection, and high-quality development of the Yellow River Basin Area as well as that for ecological construction planning and water resource management of eastern Northwest China.

Modulation of the relationship between summer temperatures in the Qinghai–Tibetan Plateau and Arctic over the past millennium by external forcings

2021 ◽  
pp. 1-9
Author(s):  
Feng Shi ◽  
Anmin Duan ◽  
Qiuzhen Yin ◽  
John T Bruun ◽  
Cunde Xiao ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Global Climate ◽  
Volcanic Eruptions ◽  
Warm Period ◽  
Temperature Correlation ◽  
The Past ◽  
External Forcings ◽  
Centennial Variation ◽  
Summer Temperatures ◽  
Past Millennium

Abstract The Qinghai–Tibetan Plateau and Arctic both have an important influence on global climate, but the correlation between climate variations in these two regions remains unclear. Here we reconstructed and compared the summer temperature anomalies over the past 1,120 yr (900–2019 CE) in the Qinghai–Tibetan Plateau and Arctic. The temperature correlation during the past millennium in these two regions has a distinct centennial variation caused by volcanic eruptions. Furthermore, the abrupt weak-to-strong transition in the temperature correlation during the sixteenth century could be analogous to this type of transition during the Modern Warm Period. The former was forced by volcanic eruptions, while the latter was controlled by changes in greenhouse gases. This implies that anthropogenic, as opposed to natural, forcing has acted to amplify the teleconnection between the Qinghai–Tibetan Plateau and Arctic during the Modern Warm Period.

scholarly journals Changes in the Tropical Pacific SST Trend from CMIP3 to CMIP5 and Its Implication of ENSO

2012 ◽  
Vol 25 (21) ◽  
pp. 7764-7771 ◽  
Author(s):  
Sang-Wook Yeh ◽  
Yoo-Geun Ham ◽  
June-Yi Lee
Keyword(s):  
Coupled Model ◽  
Research Programme ◽  
Tropical Pacific ◽  
Multimodel Ensemble ◽  
Phase 3 ◽  
Intercomparison Project ◽  
Sst Anomaly ◽  
Earth System Models ◽  
Background State ◽  
The Tropical Pacific

This study assesses the changes in the tropical Pacific Ocean sea surface temperature (SST) trend and ENSO amplitude by comparing a historical run of the World Climate Research Programme Coupled Model Intercomparison Project (CMIP) phase-5 multimodel ensemble dataset (CMIP5) and the CMIP phase-3 dataset (CMIP3). The results indicate that the magnitude of the SST trend in the tropical Pacific basin has been significantly reduced from CMIP3 to CMIP5, which may be associated with the overestimation of the response to natural forcing and aerosols by including Earth system models in CMIP5. Moreover, the patterns of tropical warming over the second half of the twentieth century have changed from a La Niña–like structure in CMIP3 to an El Niño–like structure in CMIP5. Further analysis indicates that such changes in the background state of the tropical Pacific and an increase in the sensitivity of the atmospheric response to the SST changes in the eastern tropical Pacific have influenced the ENSO properties. In particular, the ratio of the SST anomaly variance in the eastern and western tropical Pacific increased from CMIP3 to CMIP5, indicating that a center of action associated with the ENSO amplitude has shifted to the east.

Multidecadal climate oscillations during the past millennium driven by volcanic forcing

Science ◽  
2021 ◽  
Vol 371 (6533) ◽  
pp. 1014-1019
Author(s):  
Michael E. Mann ◽  
Byron A. Steinman ◽  
Daniel J. Brouillette ◽  
Sonya K. Miller
Keyword(s):  
Past Research ◽  
Atlantic Multidecadal Oscillation ◽  
Oscillatory Behavior ◽  
Time Varying ◽  
Sulfate Aerosols ◽  
Climate Oscillations ◽  
The Past ◽  
Volcanic Forcing ◽  
Climate Noise ◽  
Past Millennium

Past research argues for an internal multidecadal (40- to 60-year) oscillation distinct from climate noise. Recent studies have claimed that this so-termed Atlantic Multidecadal Oscillation is instead a manifestation of competing time-varying effects of anthropogenic greenhouse gases and sulfate aerosols. That conclusion is bolstered by the absence of robust multidecadal climate oscillations in control simulations of current-generation models. Paleoclimate data, however, do demonstrate multidecadal oscillatory behavior during the preindustrial era. By comparing control and forced “Last Millennium” simulations, we show that these apparent multidecadal oscillations are an artifact of pulses of volcanic activity during the preindustrial era that project markedly onto the multidecadal (50- to 70-year) frequency band. We conclude that there is no compelling evidence for internal multidecadal oscillations in the climate system.

African Studies Keyword: Malaria

2021 ◽  
Vol 64 (4) ◽  
pp. 959-985
Author(s):  
Melissa Graboyes ◽  
Zainab Alidina
Keyword(s):  
African Continent ◽  
Historical Knowledge ◽  
Truth Telling ◽  
The Past ◽  
Moral Problems ◽  
History Of ◽  
Global Eradication ◽  
Biomedical Interventions ◽  
Scientific Questions

AbstractFrom nearly any perspective and metric, the effects of malaria on the African continent have been persistent and deep. By focusing on the malady of malaria and the last century of biomedical interventions, Graboyes and Alidina raise critical historical, ethical, and scientific questions related to truth telling, African autonomy, and the obligations of foreign researchers. They provide a condensed history of malaria activities on the continent over the past 120 years, highlighting the overall history of failures to eliminate or control the disease. A case study of the risks of rebound malaria illustrates the practical and moral problems that abound when historical knowledge is ignored. In light of current calls for renewed global eradication efforts, Graboyes and Alidina provide evidence for why historical knowledge must be better integrated into global health epistemic realms.

scholarly journals The Meridional Shift of the Midlatitude Westerlies over Arid Central Asia during the Past 21 000 Years Based on the TraCE-21ka Simulations

2020 ◽  
Vol 33 (17) ◽  
pp. 7455-7478
Author(s):  
Nanxuan Jiang ◽  
Qing Yan ◽  
Zhiqing Xu ◽  
Jian Shi ◽  
Ran Zhang
Keyword(s):  
Indian Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Last Deglaciation ◽  
The Past ◽  
The North ◽  
External Forcings ◽  
The Indian Ocean ◽  
The Last Deglaciation ◽  
The North Atlantic

AbstractTo advance our knowledge of the response of midlatitude westerlies to various external forcings, we investigate the meridional shift of midlatitude westerlies over arid central Asia (ACA) during the past 21 000 years, which experienced more varied forcings than the present day based on a set of transient simulations. Our results suggest that the evolution of midlatitude westerlies over ACA and driving factors vary with time and across seasons. In spring, the location of midlatitude westerlies over ACA oscillates largely during the last deglaciation, driven by meltwater fluxes and continental ice sheets, and then shows a long-term equatorward shift during the Holocene controlled by orbital insolation. In summer, orbital insolation dominates the meridional shift of midlatitude westerlies, with poleward and equatorward migration during the last deglaciation and the Holocene, respectively. From a thermodynamic perspective, variations in zonal winds are linked with the meridional temperature gradient based on the thermal wind relationship. From a dynamic perspective, variations in midlatitude westerlies are mainly induced by anomalous sea surface temperatures over the Indian Ocean through the Matsuno–Gill response and over the North Atlantic Ocean by the propagation of Rossby waves, or both, but their relative importance varies across forcings. Additionally, the modeled meridional shift of midlatitude westerlies is broadly consistent with geological evidence, although model–data discrepancies still exist. Overall, our study provides a possible scenario for a meridional shift of midlatitude westerlies over ACA in response to various external forcings during the past 21 000 years and highlights important roles of both the Indian Ocean and the North Atlantic Ocean in regulating Asian westerlies, which may shed light on the behavior of westerlies in the future.

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