scholarly journals Evaluating and understanding top of the atmosphere cloud radiative effects in Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) Coupled Model Intercomparison Project Phase 5 (CMIP5) models using satellite observations

2013 ◽  
Vol 118 (2) ◽  
pp. 683-699 ◽  
Author(s):  
Hailan Wang ◽  
Wenying Su
Keyword(s):  
Climate Change ◽  
Coupled Model ◽  
Satellite Observations ◽  
Cmip5 Models ◽  
Model Intercomparison ◽  
Radiative Effects ◽  
Intergovernmental Panel ◽  
Assessment Report ◽  
Intercomparison Project ◽  
Cloud Radiative Effects

scholarly journals Avaliação de Modelos do CMIP5 que Melhor Expressam a Atuação dos Vórtices Ciclônicos em Altos Níveis (VCANS) no Nordeste Brasileiro (NEB) (Evaluation of the CMIP5 Models that Express the Best Performance of Vortice in High Levels (VCANS) in Northeast...)

2015 ◽  
Vol 7 (5) ◽  
pp. 891
Author(s):  
José Ueliton Pinheiro ◽  
Josemir Araújo Neves ◽  
Rosane Rodrigues Chaves ◽  
David Mendes ◽  
Naurinete Costa Barreto
Keyword(s):  
Climate Change ◽  
Mean Square Error ◽  
Coupled Model ◽  
Mean Square ◽  
Model Intercomparison ◽  
Intergovernmental Panel ◽  
Assessment Report ◽  
Atmospheric Research ◽  
Intercomparison Project ◽  
Environmental Prediction

A pesquisa estudou a saída de modelos de mudanças climáticas que melhor expressam a atuação dos Vórtices Ciclônicos em Altos Níveis (VCANs) no Nordeste Brasileiro (NEB). Os VCANs foram quantificados pela sua ocorrência diária durante 5 anos (1995-1999), no período de outubro a março. O objeto de estudo foram 13 modelos do CMIP5/IPCC/AR5 (Coupled Model Intercomparison Project Phase 5/Intergovernmental Panel on Climate Change/Fifth Assessment Report), comparados com os resultados do NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research), por meio de métodos estatísticos para escolha do modelo que melhor indica a presença dos VCANs no NEB. A primeira análise comparativa foi feita através das correlações de Pearson, Kendall e Spearman, Raiz quadrada do erro quadrático médio, Raiz quadrada do erro quadrático médio normalizada e os índices de Eficiência e desempenho, Nash-Sutcliffe (NSE), Kling-Gupta (KGE) e o Índice de Concordância de Willmott (d). Em seguida foram selecionados os modelos de melhor desempenho e com significância estatística para uma análise posterior de acertos e erros através dos índices: Índice de Proporção Correta (PC), Índice de Sucesso Crítico (ISC), Probabilidade de Detecção (POD), Taxa de alarme Falso (TAF) e Taxa de Tendência (VIÉS). Para os testes estatísticos aplicados na primeira avaliação realizada o modelo MIROC4h foi o que apresentou os melhores índices seguido pelo MIROC-ESM e inmCM4, respectivamente. Além destes, ainda apresentaram correlação estatística significante o MPI-ESM-LR,o MRI-CGCM3 e o CSIRO-MK3-6-0. A segunda análise também apresentou o MIROC4h com os melhores valores de PC, ISC e POD, excetuando-se o VIÉS que apresentou o segundo melhor resultado e o TAF com o pior resultado em relação aos outros 5 modelos. Dessa forma o MIROC4h apresentou-se como o mais indicado entre os modelos do CMIP5 para estudos de cenários presentes e futuros de VCANs no NEB.   A B S T R A C T The research studied the output of climate change models that best express the actions of Upper Tropospheric Cyclonic Vortices (UTCV) in high levels in the Northeast Brazil (NEB). The UTCV were quantified by a daily occurrence for 5 years (1995-1999) in the period from October to March. The object of the study were 13 models from CMIP5/IPCC/AR5 (Coupled Model Intercomparison Project Phase 5 / Intergovernmental Panel on Climate Change / Fifth Assessment Report ), compared with results from the NCEP / NCAR (National Centers for Environmental Prediction / National Center for Atmospheric Research) by means of statistical methods for choosing the model which best indicates the presence of UTCV in the NEB. The first comparative analysis was performed using the Pearson, Spearman and Kendall correlations, mean square error, normalized mean square error and efficiency and performance indices, Nash-Sutcliff (NSE), Kling-Gupta (KGE) and Index of Agreement of the Willmott (d). Then models with better performance and statistical significance for further analysis of successes and mistakes through the indices were selected: Index Proportion Correct (PC), Critical Success Index (CSI), Probability of Detection (POD), False Alarm Rate (FAR) and Trend Rate (BIAS). For the statistical analyzes used in the first test performed MIROC4h model showed the best rates followed by MIROC-ESM and inmCM4 respectively. In addition, further significant statistical correlation MPI-ESM-LR, MRI-CGCM3 and CSIRO-MK3-6-0. The second analysis also showed the MIROC4h with the best values ​​of PC, CSI and POD, except the BIAS that had the second best result and the FAR with the worst result in relation to the other five models considered in this phase. Thus the MIROC4h introduced himself as the most suitable model of the CMIP5 for studies of the present and future scenarios of UTCV in the NEB   

Nexo: água, Clima, Energia e Meio Ambiente - Uma Perspectiva sobre o Empreendimento de Itataia-CE

2020 ◽  
Vol 35 (3) ◽  
pp. 449-457
Author(s):  
Ilma Ribeiro de Lima ◽  
Cleiton da Silva Silveira ◽  
Francisco das Chagas Vasconcelos Júnior
Keyword(s):  
Climate Change ◽  
Coupled Model ◽  
Model Intercomparison ◽  
Intergovernmental Panel ◽  
Intercomparison Project

Resumo A viabilidade hídrica do Complexo Industrial de exploração e beneficiamento de urânio e fosfato em Santa Quitéria - Ceará foi analisada a partir da relação nexo água, energia e clima. Para tanto, foram usadas projeções de precipitação, evapotranspiração e vazão adotanto os modelos globais do Coupled Model Intercomparison Project Phase 5 (CMIP5, utilizados no quinto relatório do Intergovernmental Panel on Climate Change - IPCC-AR5). Dados da matriz energética do Ceará também foram considerados com o intuito de verificar o aumento da demanda energética do estado e a analisar o impacto da sua produção frente aos recursos hídircos. Os modelos divergem quanto ao futuro das precipitações, mas a maioria assinala um aumento da evapotranspiração nos três períodos projetados (2015 - 2044, 2045 - 2074 e 2075 a 2099) nos dois cenários escolhidos (RCP4.5 e RCP8.5) indicando um possível aumento da demanda hídrica para a região.

scholarly journals MJO and Convectively Coupled Equatorial Waves Simulated by CMIP5 Climate Models

2013 ◽  
Vol 26 (17) ◽  
pp. 6185-6214 ◽  
Author(s):  
Meng-Pai Hung ◽  
Jia-Lin Lin ◽  
Wanqiu Wang ◽  
Daehyun Kim ◽  
Toshiaki Shinoda ◽  
...  
Keyword(s):  
Climate Models ◽  
Intraseasonal Variability ◽  
Coupled Model ◽  
Static Stability ◽  
Cmip5 Models ◽  
Equatorial Waves ◽  
Intergovernmental Panel ◽  
Assessment Report ◽  
Convectively Coupled Equatorial Waves ◽  
Intercomparison Project

Abstract This study evaluates the simulation of the Madden–Julian oscillation (MJO) and convectively coupled equatorial waves (CCEWs) in 20 models from the Coupled Model Intercomparison Project (CMIP) phase 5 (CMIP5) in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) and compares the results with the simulation of CMIP phase 3 (CMIP3) models in the IPCC Fourth Assessment Report (AR4). The results show that the CMIP5 models exhibit an overall improvement over the CMIP3 models in the simulation of tropical intraseasonal variability, especially the MJO and several CCEWs. The CMIP5 models generally produce larger total intraseasonal (2–128 day) variance of precipitation than the CMIP3 models, as well as larger variances of Kelvin, equatorial Rossby (ER), and eastward inertio-gravity (EIG) waves. Nearly all models have signals of the CCEWs, with Kelvin and mixed Rossby–gravity (MRG) and EIG waves being especially prominent. The phase speeds, as scaled to equivalent depths, are close to the observed value in 10 of the 20 models, suggesting that these models produce sufficient reduction in their effective static stability by diabatic heating. The CMIP5 models generally produce larger MJO variance than the CMIP3 models, as well as a more realistic ratio between the variance of the eastward MJO and that of its westward counterpart. About one-third of the CMIP5 models generate the spectral peak of MJO precipitation between 30 and 70 days; however, the model MJO period tends to be longer than observations as part of an overreddened spectrum, which in turn is associated with too strong persistence of equatorial precipitation. Only one of the 20 models is able to simulate a realistic eastward propagation of the MJO.

Empfehlungen für die Charakterisierung und Benennung ausgewählter IPCC Klimaszenarien

2021 ◽  
Author(s):  
Frank Kreienkamp ◽  
Barbara Früh ◽  
Sven Kotlarski ◽  
Carsten Linke ◽  
Marc Olefs ◽  
...  
Keyword(s):  
Climate Change ◽  
Coupled Model ◽  
Model Intercomparison ◽  
Intergovernmental Panel ◽  
Representative Concentration Pathways ◽  
Intercomparison Project

<p>Eine zentrale Aufgabe von Klimaforschung und Klimakommunikation ist die Beschreibung möglicher Entwicklungspfade des künftigen Klimas sowie der antreibenden Kräfte. Diese Entwicklungspfade werden Klimaszenarien genannt. Klimaszenarien wiederum basieren auf Szenarien möglicher Entwicklung von Gesellschaft, Technologie und Ressourcennutzung, um daraus die resultierenden Emissionen von Treibhausgasen abzuschätzen. </p> <p>In der Nutzerkommunikation werden die Klimaszenarien des Intergovernmental Panel on Climate Change (IPCC) in der Regel mit prägnanten Namen beschrieben. Im deutschsprachigen Raum wurden in den letzten Jahren jedoch verschiedene Namen für dieselben Klimaszenarien genutzt. Dies führte oft zu Irritationen und Verwechslungen.</p> <p>Um dem entgegenzuwirken hat nun eine Arbeitsgruppe der drei deutschsprachigen Wetterdienste, Bundes- und Landeseinrichtungen und aus der Klimaforschung erstmals eine Empfehlung für eine einheitliche Benennung, Beschreibung und farbliche Kennzeichnung einer Auswahl von Klimaszenarien des IPCC vorgelegt. Dieses betrifft die Szenarien der CMIP6<sup>1</sup>-Generation die aus zwei sich gegenseitig ergänzenden Komponenten bestehen: den Shared Socioeconomic Pathways (SSPs) und den Representative Concentration Pathways (RCPs). Im speziellen hier die Szenarien SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0 und SSP5-8.5. Dieses sind die Szenarien die zum einen von den Modellgruppen für Modellsimulationen genutzt wurden und oder in der politischen Diskussion regelmäßig besprochen werden.</p> <p>Dieser Beitrag stellt die Empfehlungen der Arbeitsgruppe für eine einheitliche Sprach- und Kommunikationsregelung  der fünf derzeit am häufigsten genutzten Klimaszenarien im deutschsprachigen Raum vor.</p> <p><sup>1</sup> CMIP6: Coupled Model Intercomparison Project Phase 6</p>

scholarly journals Bias-corrected climate projections for South Asia from Coupled Model Intercomparison Project-6

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Vimal Mishra ◽  
Udit Bhatia ◽  
Amar Deep Tiwari
Keyword(s):  
Climate Change ◽  
Impact Assessment ◽  
South Asia ◽  
General Circulation ◽  
Coupled Model ◽  
General Circulation Models ◽  
River Basins ◽  
Climate Projections ◽  
Model Intercomparison ◽  
Intercomparison Project

Abstract Climate change is likely to pose enormous challenges for agriculture, water resources, infrastructure, and livelihood of millions of people living in South Asia. Here, we develop daily bias-corrected data of precipitation, maximum and minimum temperatures at 0.25° spatial resolution for South Asia (India, Pakistan, Bangladesh, Nepal, Bhutan, and Sri Lanka) and 18 river basins located in the Indian sub-continent. The bias-corrected dataset is developed using Empirical Quantile Mapping (EQM) for the historic (1951–2014) and projected (2015–2100) climate for the four scenarios (SSP126, SSP245, SSP370, SSP585) using output from 13 General Circulation Models (GCMs) from Coupled Model Intercomparison Project-6 (CMIP6). The bias-corrected dataset was evaluated against the observations for both mean and extremes of precipitation, maximum and minimum temperatures. Bias corrected projections from 13 CMIP6-GCMs project a warmer (3–5°C) and wetter (13–30%) climate in South Asia in the 21st century. The bias-corrected projections from CMIP6-GCMs can be used for climate change impact assessment in South Asia and hydrologic impact assessment in the sub-continental river basins.

scholarly journals Intercomparison of temperature trends in IPCC CMIP5 simulations with observations, reanalyses and CMIP3 models

2013 ◽  
Vol 6 (5) ◽  
pp. 1705-1714 ◽  
Author(s):  
J. Xu ◽  
L. Zhao ◽  
Keyword(s):  
Coupled Model ◽  
Temperature Trend ◽  
The Arctic ◽  
Cmip5 Models ◽  
Model Intercomparison ◽  
Model Simulations ◽  
Temperature Trends ◽  
Intercomparison Project ◽  
Stratospheric Cooling ◽  
The Tropics

Abstract. On the basis of the fifth Coupled Model Intercomparison Project (CMIP5) and the climate model simulations covering 1979 through 2005, the temperature trends and their uncertainties have been examined to note the similarities or differences compared to the radiosonde observations, reanalyses and the third Coupled Model Intercomparison Project (CMIP3) simulations. The results show noticeable discrepancies for the estimated temperature trends in the four data groups (radiosonde, reanalysis, CMIP3 and CMIP5), although similarities can be observed. Compared to the CMIP3 model simulations, the simulations in some of the CMIP5 models were improved. The CMIP5 models displayed a negative temperature trend in the stratosphere closer to the strong negative trend seen in the observations. However, the positive tropospheric trend in the tropics is overestimated by the CMIP5 models relative to CMIP3 models. While some of the models produce temperature trend patterns more highly correlated with the observed patterns in CMIP5, the other models (such as CCSM4 and IPSL_CM5A-LR) exhibit the reverse tendency. The CMIP5 temperature trend uncertainty was significantly reduced in most areas, especially in the Arctic and Antarctic stratosphere, compared to the CMIP3 simulations. Similar to the CMIP3, the CMIP5 simulations overestimated the tropospheric warming in the tropics and Southern Hemisphere and underestimated the stratospheric cooling. The crossover point where tropospheric warming changes into stratospheric cooling occurred near 100 hPa in the tropics, which is higher than in the radiosonde and reanalysis data. The result is likely related to the overestimation of convective activity over the tropical areas in both the CMIP3 and CMIP5 models. Generally, for the temperature trend estimates associated with the numerical models including the reanalyses and global climate models, the uncertainty in the stratosphere is much larger than that in the troposphere, and the uncertainty in the Antarctic is the largest. In addition, note that the reanalyses show the largest uncertainty in the lower tropical stratosphere, and the CMIP3 simulations show the largest uncertainty in both the south and north polar regions.

scholarly journals Comparison of Monthly Temperature Extremes Simulated by CMIP3 and CMIP5 Models

2013 ◽  
Vol 26 (19) ◽  
pp. 7692-7707 ◽  
Author(s):  
Yao Yao ◽  
Yong Luo ◽  
Jianbin Huang ◽  
Zongci Zhao
Keyword(s):  
Coupled Model ◽  
Cmip5 Models ◽  
Temperature Extremes ◽  
Extreme Temperatures ◽  
Model Intercomparison ◽  
Annual Cycles ◽  
Monthly Temperature ◽  
Intercomparison Project ◽  
Cmip3 Ensemble ◽  
Cold Extremes

Abstract The extreme monthly-mean temperatures simulated by 28 models in the fifth phase of the Coupled Model Intercomparison Project (CMIP5) are evaluated and compared with those from 24 models in the third phase of the Coupled Model Intercomparison Project (CMIP3). Comparisons with observations and reanalyses indicate that the models from both CMIP3 and CMIP5 perform well in simulating temperature extremes, which are expressed as 20-yr return values. When the climatological annual cycle is removed, the ensemble spread in CMIP5 is smaller than that in CMIP3. Benefitting from a higher resolution, the CMIP5 models perform better at simulating extreme temperatures on the local gridcell scale. The CMIP5 representative concentration pathway (RCP4.5) and CMIP3 B1 experiments project a similar change pattern in the near future for both warm and cold extremes, and the pattern is in agreement with that of the seasonal extremes. By the late twenty-first century, the changes in monthly temperature extremes projected under the three CMIP3 (B1, A1B, and A2) and two CMIP5 (RCP4.5 and RCP8.5) scenarios generally follow the changes in climatological annual cycles, which is consistent with previous studies on daily extremes. Compared with the CMIP3 ensemble, the CMIP5 ensemble shows a larger intermodel uncertainty with regard to the change in cold extremes in snow-covered regions. Enhanced changes in extreme temperatures that exceed the global mean warming are found in regions where the retreat of snow (or the soil moisture feedback effect) plays an important role, confirming the findings for daily temperature extremes.

Challenges in Constraining Future Change of Global Land Precipitation in CMIP6 Models

2020 ◽  
Author(s):  
June-Yi Lee ◽  
Kyung-Sook Yun ◽  
Arjun Babu ◽  
Young-Min Yang ◽  
Eui-Seok Chung ◽  
...  
Keyword(s):  
Global Warming ◽  
Emission Scenario ◽  
Coupled Model ◽  
Precipitation Change ◽  
Cmip5 Models ◽  
Model Intercomparison ◽  
Projected Change ◽  
Global Land ◽  
Intercomparison Project ◽  
Global Mean

<p><span>The Coupled Model Intercomparison Project Phase 5 (CMIP5) models have showed substantial inter-model spread in estimating annual global-mean precipitation change per one-degree greenhouse-gas-induced warming (precipitation sensitivity), ranging from -4.5</span><span>–4.2</span><span>%</span><sup><span>o</span></sup><span>C<sup>-1</sup>in the Representative Concentration Pathway (RCP) 2.6, the lowest emission scenario, to 0.2–4.0</span><span>%</span><sup><span>o</span></sup><span>C<sup>-1</sup>in the RCP 8.5, the highest emission scenario. The observed-based estimations in the global-mean land precipitation sensitivity during last few decades even show much larger spread due to the considerable natural interdecadal variability, role of anthropogenic aerosol forcing, and uncertainties in observation. This study tackles to better quantify and constrain global land precipitation change in response to global warming by analyzing the new range of Shared Socio-economic Pathway (SSP) scenarios in the </span><span>Coupled Model Intercomparison Project Phase 6 (CMIP6) compared with RCP scenarios in the CMIP5. We show that the range of projected change in annual global-mean land (ocean) precipitation by the end of the 21<sup>st</sup>century relative to the recent past (1995-2014) in the 23 CMIP6 models is over 50% (20%) larger than that in corresponding scenarios of the 40 CMIP5 models. The estimated ranges of precipitation sensitivity in four Tier-1 SSPs are also larger than those in corresponding CMIP5 RCPs. The large increase in projected precipitation change in the highest quartile over ocean is mainly due to the increased number of high equilibrium climate sensitivity (ECS) models in CMIP6 compared to CMIP5, but not over land due to different response of thermodynamic moisture convergence and dynamic processes to global warming. We further discuss key challenges in constraining future precipitation change and source of uncertainties in land precipitation change.</span></p>

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