共查询到20条相似文献，搜索用时 109 毫秒
1.
An overview of Chinese contribution to Coupled Model Intercomparison Project–Phase 5(CMIP5) is presented. The performances of five Chinese Climate/Earth System Models that participated in the CMIP5 project are assessed in the context of climate mean states, seasonal cycle, intraseasonal oscillation, interannual variability, interdecadal variability, global monsoon, Asian-Australian monsoon, 20th-century historical climate simulation, climate change projection, and climate sensitivity. Both the strengths and weaknesses of the models are evaluated. The models generally show reasonable performances in simulating sea surface temperature(SST) mean state, seasonal cycle, spatial patterns of Madden–Julian oscillation(MJO) amplitude and tropical cyclone Genesis Potential Index(GPI), global monsoon precipitation pattern, El Nio–Southern Oscillation(ENSO), and Pacific Decadal Oscillation(PDO) related SST anomalies. However, the performances of the models in simulating the time periods, amplitude, and phase locking of ENSO, PDO time periods, GPI magnitude, MJO propagation, magnitude of SST seasonal cycle, northwestern Pacific monsoon and North American monsoon domains, as well as the skill of large-scale Asian monsoon precipitation need to be improved. The model performances in simulating the time evolution and spatial pattern of the20th-century global warming and the future change under representative concentration pathways projection are compared to the multimodel ensemble of CMIP5 models. The model discrepancies in terms of climate sensitivity are also discussed. 相似文献
2.
Statistical Downscaling for Multi-Model Ensemble Prediction
of Summer Monsoon Rainfall in the Asia-Pacific
Region Using Geopotential Height Field 总被引：16，自引：1，他引：15
The 21-yr ensemble predictions of model precipitation and circulation in the East Asian and western North Pacific （Asia-Pacific） summer monsoon region （0°-50°N, 100° 150°E） were evaluated in nine different AGCM, used in the Asia-Pacific Economic Cooperation Climate Center （APCC） multi-model ensemble seasonal prediction system. The analysis indicates that the precipitation anomaly patterns of model ensemble predictions are substantially different from the observed counterparts in this region, but the summer monsoon circulations are reasonably predicted. For example, all models can well produce the interannual variability of the western North Pacific monsoon index （WNPMI） defined by 850 hPa winds, but they failed to predict the relationship between WNPMI and precipitation anomalies. The interannual variability of the 500 hPa geopotential height （GPH） can be well predicted by the models in contrast to precipitation anomalies. On the basis of such model performances and the relationship between the interannual variations of 500 hPa GPH and precipitation anomalies, we developed a statistical scheme used to downscale the summer monsoon precipitation anomaly on the basis of EOF and singular value decomposition （SVD）. In this scheme, the three leading EOF modes of 500 hPa GPH anomaly fields predicted by the models are firstly corrected by the linear regression between the principal components in each model and observation, respectively. Then, the corrected model GPH is chosen as the predictor to downscale the precipitation anomaly field, which is assembled by the forecasted expansion coefficients of model 500 hPa GPH and the three leading SVD modes of observed precipitation anomaly corresponding to the prediction of model 500 hPa GPH during a 19-year training period. The cross-validated forecasts suggest that this downscaling scheme may have a potential to improve the forecast skill of the precipitation anomaly in the South China Sea, western North Pacific and the East Asia Pacific regions, wh 相似文献
3.
Major modes of short-term climate variability in the newly developed NUIST Earth System Model (NESM) 总被引：1，自引：0，他引：1
Jian Cao Bin Wang Baoqiang Xiang Juan Li Tianjie Wu Xiouhua Fu Liguang Wu Jinzhong Min 《大气科学进展》2015,32(5):585-600
A coupled earth system model(ESM) has been developed at the Nanjing University of Information Science and Technology(NUIST) by using version 5.3 of the European Centre Hamburg Model(ECHAM), version 3.4 of the Nucleus for European Modelling of the Ocean(NEMO), and version 4.1 of the Los Alamos sea ice model(CICE). The model is referred to as NUIST ESM1(NESM1). Comprehensive and quantitative metrics are used to assess the model's major modes of climate variability most relevant to subseasonal-to-interannual climate prediction. The model's assessment is placed in a multi-model framework. The model yields a realistic annual mean and annual cycle of equatorial SST, and a reasonably realistic precipitation climatology, but has difficulty in capturing the spring–fall asymmetry and monsoon precipitation domains. The ENSO mode is reproduced well with respect to its spatial structure, power spectrum, phase locking to the annual cycle, and spatial structures of the central Pacific(CP)-ENSO and eastern Pacific(EP)-ENSO; however, the equatorial SST variability,biennial component of ENSO, and the amplitude of CP-ENSO are overestimated. The model captures realistic intraseasonal variability patterns, the vertical-zonal structures of the first two leading predictable modes of Madden–Julian Oscillation(MJO), and its eastward propagation; but the simulated MJO speed is significantly slower than observed. Compared with the T42 version, the high resolution version(T159) demonstrates improved simulation with respect to the climatology, interannual variance, monsoon–ENSO lead–lag correlation, spatial structures of the leading mode of the Asian–Australian monsoon rainfall variability, and the eastward propagation of the MJO. 相似文献
4.
Teleconnection between Winter Arctic Oscillation and Southeast Asian Summer Monsoon in the Pre-Industry Simulation of a Coupled Climate Model 
下载免费PDF全文
下载免费PDF全文 A 600-year pre-industrial simulation with Bergen Climate Model(BCM)Version 2 is used to investigate the linkage between winter Arctic Oscillation(AO)and the Southeast Asian summer monsoon(SEASM)on the inter-decadal timescale.The results indicate an in-phase relationship between the AO and SEASM with periods of approximately 16–32 and 60–80 years.During the positive phase of winter AO,an anomalous surface anti-cyclonic atmosphere circulation appears over North Pacific in winter.The corresponding anomalies in ocean circulation and surface heat flux,particularly the latent and sensible heat flux,resemble a negative Pacific Decadal Oscillation(PDO)-like sea surface temperature(SST)pattern.The AO-associated PDO-like winter SST can persist into summer and can therefore lead to inter-decadal variability of summer monsoon rainfall in East and Southeast Asia. 相似文献
5.
We demonstrate that there is significant skill in the GloSea5 operational seasonal forecasting system for predicting June mean rainfall in the middle/lower Yangtze River basin up to four months in advance.Much of the rainfall in this region during June is contributed by the mei-yu rain band.We find that similar skill exists for predicting the East Asian summer monsoon index(EASMI)on monthly time scales,and that the latter could be used as a proxy to predict the regional rainfall.However,there appears to be little to be gained from using the predicted EASMI as a proxy for regional rainfall on monthly time scales compared with predicting the rainfall directly.Although interannual variability of the June mean rainfall is affected by synoptic and intraseasonal variations,which may be inherently unpredictable on the seasonal forecasting time scale,the major influence of equatorial Pacific sea surface temperatures from the preceding winter on the June mean rainfall is captured by the model through their influence on the western North Pacific subtropical high.The ability to predict the June mean rainfall in the middle and lower Yangtze River basin at a lead time of up to 4 months suggests the potential for providing early information to contingency planners on the availability of water during the summer season. 相似文献
6.
1 INTRODUCTION An important constituent in the Asian summer monsoon system, the West Pacific subtropical high (simplified as the 揌igh) is closely related with the activity of summer monsoon via the changes in intraseasonal intensity and progression[1 - 8]. Zhang et al[5]. discuss the relationship between seasonal jumps and anomalous location of the Highs ridge and onset of low-latitude westerlies and tropical convection in summer, with the finding that the northward jump of the High is … 相似文献
7.
Chinese Contribution to CMIP5：An Overview of Five Chinese Models’Performances 总被引：4，自引：0，他引：4 下载免费PDF全文
下载免费PDF全文 ZHOU Tianjun CHEN Xiaolong DONG Lu WU Bo MAN Wenmin ZHANG Lixi LIN Renping YAO Junchen SONG Fengfei ZHAO Chongbo 《Acta Meteorologica Sinica》2014,28(4):481-509
An overview of Chinese contribution to Coupled Model Intercomparison Project-Phase 5 （CMIP5） is presented. The performances of five Chinese Climate/Earth System Models that participated in the CMIP5 pro ject are assessed in the context of climate mean states, seasonal cycle, intraseasonal oscillation, interan-nual variability, interdecadal variability, global monsoon, Asian-Australian monsoon, 20th-century historical climate simulation, climate change pro jection, and climate sensitivity. Both the strengths and weaknesses of the models are evaluated. The models generally show reasonable performances in simulating sea surface tem-perature （SST） mean state, seasonal cycle, spatial patterns of Madden-Julian oscillation （MJO） amplitude and tropical cyclone Genesis Potential Index （GPI）, global monsoon precipitation pattern, El Ni-no-Southern Oscillation （ENSO）, and Pacific Decadal Oscillation （PDO） related SST anomalies. However, the perfor-mances of the models in simulating the time periods, amplitude, and phase locking of ENSO, PDO time periods, GPI magnitude, MJO propagation, magnitude of SST seasonal cycle, northwestern Pacific mon-soon and North American monsoon domains, as well as the skill of large-scale Asian monsoon precipitation need to be improved. The model performances in simulating the time evolution and spatial pattern of the 20th-century global warming and the future change under representative concentration pathways pro jection are compared to the multimodel ensemble of CMIP5 models. The model discrepancies in terms of climate sensitivity are also discussed. 相似文献
8.
This study introduces a new global climate model—the Integrated Climate Model(ICM)—developed for the seasonal prediction of East Asian–western North Pacific(EA–WNP) climate by the Center for Monsoon System Research at the Institute of Atmospheric Physics(CMSR, IAP), Chinese Academy of Sciences. ICM integrates ECHAM5 and NEMO2.3 as its atmospheric and oceanic components, respectively, using OASIS3 as the coupler. The simulation skill of ICM is evaluated here, including the simulated climatology, interannual variation, and the influence of El Nińo as one of the most important factors on EA–WNP climate. ICM successfully reproduces the distribution of sea surface temperature(SST) and precipitation without climate shift, the seasonal cycle of equatorial Pacific SST, and the precipitation and circulation of East Asian summer monsoon. The most prominent biases of ICM are the excessive cold tongue and unrealistic westward phase propagation of equatorial Pacific SST. The main interannual variation of the tropical Pacific SST and EA–WNP climate—El Nińo and the East Asia–Pacific Pattern—are also well simulated in ICM, with realistic spatial pattern and period. The simulated El Nińo has significant impact on EA–WNP climate, as in other models. The assessment shows ICM should be a reliable model for the seasonal prediction of EA–WNP climate. 相似文献
9.
Two types of three-dimensional circulation of the East Asian summer monsoon(EASM) act as the coupling wheels determining the seasonal rainfall anomalies in China during 1979–2015. The first coupling mode features the interaction between the Mongolian cyclone over North Asia and the South Asian high(SAH) anomalies over the Tibetan Plateau at 200 hPa. The second mode presents the coupling between the anomalous low-level western Pacific anticyclone and upperlevel SAH via the meridional flow over Southeast Asia. These two modes are responsible for the summer rainfall anomalies over China in 24 and 7 out of 37 years, respectively. However, the dominant SST anomalies in the tropical Pacific, the Indian Ocean, and the North Atlantic Ocean fail to account for the first coupling wheel's interannual variability, illustrating the challenges in forecasting summer rainfall over China. 相似文献
10.
Ping Huang Pengfei Wang Kaiming Hu Gang Huang Zhihua Zhang Yong Liu Bangliang Yan 《大气科学进展》2014,31(5):1136-1146
This study introduces a new global climate model--the Integrated Climate Model （ICM）--developed for the seasonal prediction of East Asian-western North Pacific （EA-WNP） climate by the Center for Monsoon System Research at the Institute of Atmospheric Physics （CMSR, IAP）, Chinese Academy of Sciences. ICM integrates ECHAM5 and NEMO2.3 as its atmospheric and oceanic components, respectively, using OASIS3 as the coupler. The simulation skill of ICM is evaluated here, including the simulated climatology, interannual variation, and the influence of E1 Nifio as one of the most important factors on EA-WNP climate. ICM successfully reproduces the distribution of sea surface temperature （SST） and precipitation without climate shift, the seasonal cycle of equatorial Pacific SST, and the precipitation and circulation of East Asian summer monsoon. The most prominent biases of ICM are the excessive cold tongue and unrealistic westward phase propagation of equatorial Pacific SST. The main interannual variation of the tropical Pacific SST and EA-WNP climate E1 Nifio and the East Asia-Pacific Pattern--are also well simulated in ICM, with realistic spatial pattern and period. The simulated E1 Nifio has significant impact on EA-WNP climate, as in other models. The assessment shows ICM should be a reliable model for the seasonal prediction of EA-WNP climate. 相似文献
11.
Climate modeling studies in the context of Indian summer monsoon (ISM) variability have usually been performed on the seasonal and interannual timescales. The present study assesses the fidelity of the Regional Climate Model (RegCM v4.6) in capturing the subseasonal active and break spells along with the seasonal mean rainfall during the ISM season. The model fields are obtained from 24 years (1982–2005) of simulation and validated against the observations and latest reanalyzed ERA5 data products. Our analysis indicates that RegCM v4.6 fairly captures the large scale features of ISM and improvement in seasonal rainfall is noted as compared to its precedent RegCM v4.4. At subseasonal timescales, though the model captures the active and break spells of ISM, the length and frequency of these events seem inconsistent as compared to the observations. Occurrences of breaks and associated circulation features are mostly consistent but the active spells are significantly misconstrued in the model. The dry air intrusion from the western region and lack of monsoon low over the mainland and Bay of Bengal seem to suppress the precipitation in the model. This subseasonal bias might persist due to systematic errors linked to the lack of ocean coupling, inefficiency of land surface and cumulus parameterization schemes in the model. Overall, RegCM v4.6 offers improvements at seasonal timescale but needs further improvements to realistically represent the subseasonal variability of ISM. 相似文献
12.
13.
The reproducibility of boreal summer intraseasonal variability (ISV) and its interannual variation by dynamical models are
assessed through diagnosing 21-year retrospective forecasts from ten state-of-the-art ocean–atmosphere coupled prediction
models. To facilitate the assessment, we have defined the strength of ISV activity by the standard deviation of 20–90 days
filtered precipitation during the boreal summer of each year. The observed climatological ISV activity exhibits its largest
values over the western North Pacific and Indian monsoon regions. The notable interannual variation of ISV activity is found
primarily over the western North Pacific in observation while most models have the largest variability over the central tropical
Pacific and exhibit a wide range of variability in spatial patterns that are different from observation. Although the models
have large systematic biases in spatial pattern of dominant variability, the leading EOF modes of the ISV activity in the
models are closely linked to the models’ El Nino-Southern Oscillation (ENSO), which is a feature that resembles the observed
ISV and ENSO relationship. The ENSO-induced easterly vertical shear anomalies in the western and central tropical Pacific,
where the summer mean vertical wind shear is weak, result in ENSO-related changes of ISV activity in both observation and
models. It is found that the principal components of the predicted dominant modes of ISV activity fluctuate in a very similar
way with observed ones. The model biases in the dominant modes are systematic and related to the external SST forcing. Thus
the statistical correction method of this study based on singular value decomposition is capable of removing a large portion
of the systematic errors in the predicted spatial patterns. The 21-year-averaged pattern correlation skill increases from
0.25 to 0.65 over the entire Asian monsoon region after applying the bias correction method to the multi-model ensemble mean
prediction. 相似文献
14.
Even though multi-model prediction systems may have better skill in predicting the interannual variability (IAV) of Indian
summer monsoon (ISM), the overall performance of the system is limited by the skill of individual models (single model ensembles).
The DEMETER project aimed at seasonal-to-interannual prediction is not an exception to this case. The reasons for the poor
skill of the DEMETER individual models in predicting the IAV of monsoon is examined in the context of the influence of external
and internal components and the interaction between intraseasonal variability (ISV) and IAV. Recently it has been shown that
the ISV influences the IAV through very long breaks (VLBs; breaks with duration of more than 10 days) by generating droughts.
Further, all VLBs are associated with an eastward propagating Madden–Julian Oscillation (MJO) in the equatorial region, facilitated
by air–sea interaction on intraseasonal timescales. This VLB-drought–MJO relationship is analyzed here in detail in the DEMETER
models. Analyses indicate that the VLB-drought relationship is poorly captured by almost all the models. VLBs in observations
are generated through air–sea interaction on intraseasonal time scale and the models’ inability to simulate VLB-drought relationship
is shown to be linked to the models’ inability to represent the air–sea interaction on intraseasonal time scale. Identification
of this particular deficiency of the models provides a direction for improvement of the model for monsoon prediction. 相似文献
15.
Climate Dynamics - Onset and demise of the Indian summer monsoon (ISM) and intraseasonal variability (ISV) embedded within the ISM are dominant climatological phenomena observed over the Indian... 相似文献
16.
The interactions among the Asian-Pacific monsoon subsystems have significant impacts on the climatic regimes in the monsoon region and even the whole world. Based on the domestic and foreign related research, an analysis is made of four different teleconnection modes found in the Asian-Pacific monsoon region, which reveal clearly the interactions among the Indian summer monsoon （ISM）, the East Asian summer monsoon （EASM）, and the western North Pacific summer monsoon （WNPSM）. The results show that： （1） In the period of the Asian monsoon onset, the date of ISM onset is two weeks earlier than the beginning of the Meiyu over the Yangtze River Basin, and a teleconnection mode is set up from the southwestern India via the Bay of Bengal （BOB） to the Yangtze River Basin and southern Japan, i.e., the ＂southern＂ teleconnection of the Asian summer monsoon. （2） In the Asian monsoon culmination period, the precipitation of the Yangtze River Basin is influenced significantly by the WNPSM through their teleconnection relationship, and is negatively related to the WNPSM rainfall, that is, when the WNPSM is weaker than normal, the precipitation of the Yangtze River Basin is more than normal. （3） In contrast to the rainfall over the Yangtze River Basin, the precipitation of northern China （from the 4th pentad of July to the 3rd pentad of August） is positively related to the WNPSM. When the WNPSM is stronger than normal, the position of the western Pacific subtropical high （WPSH） becomes farther northeast than normal, the anomalous northeastward water vapor transport along the southwestern flank of WPSH is converged over northern China, providing adequate moisture for more rainfalls than normal there. （4） The summer rainfall in northern China has also a positive correlation with the ISM. During the peak period of ISM, a teleconnection pattern is formed from Northwest India via the Tibetan Plateau to northern China, i.e., the ＂northern＂ teleconnection of the Asian summer monsoon. The 相似文献
17.
Interannual variability of the convective activities associated with the east asian summer monsoon obtained from tbb variability 总被引：5，自引：0，他引：5
１．ＩｎｔｒｏｄｕｃｔｉｏｎＳｏｕｔｈＡｓｉａａｎｄＥａｓｔＡｓｉａａｒｅａｈｕｇｅｍｏｎｓｏｏｎｓｙｓｔｅｍ,ｉｎｗｈｉｃｈｔｈｅＥａｓｔＡｓｉａｎｍｏｎｓｏｏｎｉｓｉｔｓｓｕｂｍｏｎｓｏｏｎｓｙｓｔｅｍ．ＢｅｃａｕｓｅｔｈｅＥａｓｔＡｓｉａｎｓｕ... 相似文献
18.
亚洲—太平洋夏季风系统的基本模态特征分析 总被引：5，自引：1，他引：4
亚洲—太平洋季风区各季风子系统间的相互作用对季风区甚至全球的气候变化都有着显著的影响.整个亚洲—太平洋夏季风系统都处于高层辐散、低层辐合的庞大辐散环流中,从高层辐散中心流出的三支气流分别对推动印度夏季风、东亚副热带夏季风和南海夏季风起着重要的作用,很好地表现了亚洲—太平洋夏季风系统的整体性特征.季风区多种气象要素的基本模态在年代际和年际尺度上都表现出较为一致的变化特征:年代际尺度上亚洲—太平洋夏季风系统整体呈现减弱趋势;年际尺度上存在准2年和准4年的两个周期,其中准2年振荡特征表现为若印度西南季风偏强,则印度季风雨带偏强偏北,导致印度大陆中北部地区降水偏多;同时,由于西太平洋副热带高压的北移和偏强的印度西南季风显著向东延伸,10°N~30°N范围内的西北太平洋地区则表现为异常的气旋性环流,而30°N~50°N之间为反气旋性环流异常,对应东亚夏季风偏强,季风雨带能够北推至我国华北地区.也就是说,当亚洲夏季风中某一季风子系统表现为异常偏强时,另一季风子系统在这一年中也将表现为异常偏强,反之亦然.准2年的振荡周期可能是亚洲—太平洋夏季风系统的一种固有振荡,它从年际尺度上反映了亚洲—太平洋夏季风受热带太平洋—印度洋海温的强迫表现出明显的整体一致特征. 相似文献
19.
气候平均状况下亚洲夏季风的季节内演变过程 总被引：5，自引：0，他引：5
根据1979—1995年美国NOAA的向外长波辐射逐日资料,用功率谱分析和带通滤波方法,对气候平均状况下亚洲夏季风的季节内演变过程进行分析,归纳得到亚洲季风区各个子系统季节内变化的8个关键阶段。利用1979—1999年NCEP/NCAR的大气环流再分析资料及中国气象局降水资料CMAP,对每个关键阶段亚洲夏季风的环流和降水的时空演变特征进行分析,得到亚洲季风区环流和降水季节内变化的物理图像。研究表明,在不同的季节内演变阶段,亚洲夏季风各个子系统成员的环流系统的变化特征可以将亚洲夏季风系统的季节内演变过程较好地描述出来。 相似文献
20.
西北太平洋夏季风对中国长江流域夏季降水的影响 总被引：11，自引：5，他引：6
利用1979～2005年NCEP/NCAR的环流场再分析资料和降水资料, 通过对季风期降水、 大气环流、 水汽输送及低频振荡等方面的分析, 分别从时间和空间上分析了西北太平洋夏季风与中国长江流域夏季降水的联系。结果表明:(1) 西北太平洋夏季风与中国长江流域夏季降水存在显著的负相关关系, 在西北太平洋夏季风强盛时, 副热带高压异常偏北, 其西侧的偏南气流异常偏弱, 使得我国长江流域形成低层异常环流及水汽输送的辐散区, 从而造成长江流域夏季降水偏少; 而在西北太平洋夏季风减弱的年份, 西太平洋副高异常偏南偏西, 在长江流域以南地区形成异常偏强的偏南风水汽输送, 使得长江流域成为南、 北距平风的汇合区, 其上空对流活动异常活跃, 非常有利于长江流域的降水。 (2) 东亚局地Hadley垂直环流在强、 弱季风年也显著不同, 在强季风年里, Hadley局地环流异常偏弱, 长江流域上空出现的下沉运动距平, 使得该地区降水减弱, 而弱季风年则正好相反。 (3) 西北太平洋夏季风存在显著的气候平均的大气季节内振荡 (CISO), 在西北太平洋夏季风减弱时期, 长江流域降水同时受到源自热带西北太平洋西传CISO和源自热带印度洋东传CISO的共同影响, 可能造成了某种锁相关系, 从而造成降水偏多; 而在强季风年里长江流域只受由西太平洋西传的CISO的影响, 不容易激发降水。 相似文献