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1.
AGCMStudyontheMechanismofSeasonalAbruptChangesWangHuijun(王会军)andZengQingcun(曾庆存)(LASG,InstituteofAtmosphericPhysics,ChineseAc...  相似文献   

2.
Winter Asia Jetstream and Seasonal Precipitation in East China   总被引:9,自引:0,他引:9  
WinterAsiaJetstreamandSeasonalPrecipitationinEastChina¥LitrngPingde(梁平德)andLiuAixia(刘爱霞)WinterAsiaJetstreamandSeasonalPrecipi?..  相似文献   

3.
SeasonalandSpatialVariationofRadiativeEfectsofAnthropogenicSulfateAerosolQianYun(钱云),WangHongqi(汪宏七)FuCongbin(符淙斌),WangZifa(王...  相似文献   

4.
Two-wavelength Lidar Measurement of Cloud-aerosol Optical Properties   总被引:1,自引:0,他引:1  
Two-wavelengthLidarMeasurementofCloud-aerosolOpticalPropertiesQiuJinhuan(邱金桓)(InshtuteofAtmosphericPhysics,ChineseAcademyofSc...  相似文献   

5.
ENSO,particularlytheoccurenceofENSOisstilanimportantresearchobjectinclimaticvariation.UsingtheECMWFdata,therelationshipbetwenENSOandtheactivitiesoflow-frequencywavesinthetropicalatmosphereisanalyzedinthispaper.ItisshownthattheocurenceofENSOiscloselyrelatedtotheintraseasonaloscilationandthequasi-stationarywaves(theperiod>90days)inthetropicalatmosphere.AsociatedwiththeocurenceofElNinoevent,thekineticenergyoflow-frequencywaveshasobviousvariation:thekineticenergyofatmosphericintraseasonal(30-60days)oscilation  相似文献   

6.
TheSouthChinaSeaMonsoonExperiment(SCSMEX)ImplementationPlanDingYihui(丁一汇),ChaoQingchen(巢清尘),ZhangYan(张雁),GanZijun(甘子钧)①andZha...  相似文献   

7.
NonlinearRetrievalofAtmosphericOzoneProfilefromSolarBackscaterUltravioletMeasurements:TheoryandSimulation①LiJun(李俊)andLuDaren...  相似文献   

8.
TheQuasi-DecadalOscilationofAir-SeaSystemintheNorthwesternPacificRegion①LiChongyin(李崇银)LASG,InstituteofAtmosphericPhysics,Chi...  相似文献   

9.
ObservationalStudyontheOnsetoftheSouthChinaSeaSouthwestMonsoonYanJunyue(阎俊岳)NationalClimateCenter,Beijing100081ReceivedNovemb...  相似文献   

10.
Xu Qun 《大气科学进展》1995,12(2):215-224
AnalysisofCausesandSeasonalPredictionoftheSevereFloodsinYangtze/HuaiheBasinsduringSummer1991XuQun(徐群)(JiangsuMeteorologicalin...  相似文献   

11.
A semi-operational real time short-term climate prediction system has been developed in the Center of Climate and Environment Prediction Research (CCEPRE), Institute of Atmospheric Physics / Chinese Academy of Sciences. The system consists of the following components: the AGCM and OGCM and their coupling, initial conditions and initialization, practical schemes of anomaly prediction, ensemble prediction and its standard deviation, correction of GCM output, and verification of prediction. The experiences of semi-operational real-time prediction by using this system for six years 1989-1994) and of hindcasting for 1980-1989 are reported. It is shown that in most cases large positive and negative anomalies of summer precipitation resulting in disastrous climate events such as severe flood or drought over East Asia can be well predicted for two seasons in advance, although the quantitatively statistical skill scores are only satisfactory due to the difficulty in correctly predicting the signs of small anomalies. Some methods for removing the systematic errors and introducing corrections to the GCM output arc suggested. The sensitivity of pre-diction to the initial conditions and the problem of ensemble prediction are also discussed in the paper  相似文献   

12.
Recent advances in dynamical climate prediction at the Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP/CAS) during the last five years have been briefly described in this paper. Firstly,the second generation of the IAP dynamical climate prediction system (IAP DCP-II) has been described,and two sets of hindcast experiments of the summer rainfall anomalies over China for the periods of 1980-1994 with different versions of the IAP AGCM have been conducted. The comparison results show that the predictive skill of summer rainfall anomalies over China is improved with the improved IAP AGCM in which the surface albedo parameterization is modified. Furthermore, IAP DCP-II has been applied to the real-time prediction of summer rainfall anomalies over China since 1998, and the verification results show that IAP DCP-II can quite well capture the large scale patterns of the summer flood/drought situations over China during the last five years (1998-2002). Meanwhile, an investigation has demonstrated the importance of the atmospheric initial conditions on the seasonal climate prediction, along with studies on the influences from surface boundary conditions (e.g., land surface characteristics, sea surface temperature).Certain conclusions have been reached, such as, the initial atmospheric anomalies in spring may play an important role in the summer climate anomalies, and soil moisture anomalies in spring can also have a significant impact on the summer climate anomalies over East Asia. Finally, several practical techniques(e.g., ensemble technique, correction method, etc.), which lead to the increase of the prediction skill for summer rainfall anomalies over China, have also been illustrated. The paper concludes with a list of criticalre quirements needed for the further improvement of dynamical seasonal climate prediction.  相似文献   

13.
采用一套多指标的评估方法, 对中国科学院大气物理所研制的短期气候距平数值预测系统(IAPPSSCA) 方案1 的预测性能进行了定量的、系统的评估。评估表明: IAPPSSCA 对中国汛期大尺度的、重大的降水异常预报较好; 在不同区域,IAPPSSCA 的预测能力不同, 对中国东南区域显示出较高的预报准确度和可信度; 与单个预报相比, 集合预测水平稳定, 能提高总体预测水平。另外, 还对订正技术进行了改进研究, 距平百分率订正较距平订正效果为佳。  相似文献   

14.
利用大气环流模式模拟北大西洋海温异常强迫响应   总被引:3,自引:1,他引:3  
李建  周天军  宇如聪 《大气科学》2007,31(4):561-570
北大西洋地区的海温异常能够在多大程度上对大气产生影响,一直是一个有争议的问题。作者利用伴随北大西洋涛动出现的海温异常对大气环流模式CAM2.0.1进行强迫,考察了模式在冬季(12月、1月和2月)对三核型海温异常的响应。通过与欧洲中期天气预报中心提供的再分析资料的对比,发现该模式可以通过海温强迫在一定程度上再现具有北大西洋涛动特征的温度场和环流场。在北大西洋及其沿岸地区,模式模拟出了三核型的准正压响应,与经典的北大西洋涛动型大气异常是一致的。模式结果与北大西洋地区大气内部主导模态的差别主要体现在两个方面:一是异常中心位置多偏向于大洋上空,在陆地上的异常响应强度很弱;二是高纬地区对海温异常的响应不显著,没有强迫出与实际的大气模态相对应的异常中心,表明该地区海洋的反馈作用较弱。  相似文献   

15.
On the basis of two ensemble experiments conducted by a general atmospheric circulation model (Institute of Atmospheric Physics nine-level atmospheric general circulation model coupled with land surface model, hereinafter referred to as IAP9L_CoLM), the impacts of realistic Eurasian snow conditions on summer climate predictability were investigated. The predictive skill of sea level pressures (SLP) and middle and upper tropospheric geopotential heights at mid-high latitudes of Eurasia was enhanced when improved Eurasian snow conditions were introduced into the model. Furthermore, the model skill in reproducing the interannual variation and spatial distribution of the surface air temperature (SAT) anomalies over China was improved by applying realistic (prescribed) Eurasian snow conditions. The predictive skill of the summer precipitation in China was low; however, when realistic snow conditions were employed, the predictability increased, illustrating the effectiveness of the application of realistic Eurasian snow conditions. Overall, the results of the present study suggested that Eurasian snow conditions have a significant effect on dynamical seasonal prediction in China. When Eurasian snow conditions in the global climate model (GCM) can be more realistically represented, the predictability of summer climate over China increases.  相似文献   

16.
This study extends a stochastic downscaling methodology to generation of an ensemble of hourly time series of meteorological variables that express possible future climate conditions at a point-scale. The stochastic downscaling uses general circulation model (GCM) realizations and an hourly weather generator, the Advanced WEather GENerator (AWE-GEN). Marginal distributions of factors of change are computed for several climate statistics using a Bayesian methodology that can weight GCM realizations based on the model relative performance with respect to a historical climate and a degree of disagreement in projecting future conditions. A Monte Carlo technique is used to sample the factors of change from their respective marginal distributions. As a comparison with traditional approaches, factors of change are also estimated by averaging GCM realizations. With either approach, the derived factors of change are applied to the climate statistics inferred from historical observations to re-evaluate parameters of the weather generator. The re-parameterized generator yields hourly time series of meteorological variables that can be considered to be representative of future climate conditions. In this study, the time series are generated in an ensemble mode to fully reflect the uncertainty of GCM projections, climate stochasticity, as well as uncertainties of the downscaling procedure. Applications of the methodology in reproducing future climate conditions for the periods of 2000–2009, 2046–2065 and 2081–2100, using the period of 1962–1992 as the historical baseline are discussed for the location of Firenze (Italy). The inferences of the methodology for the period of 2000–2009 are tested against observations to assess reliability of the stochastic downscaling procedure in reproducing statistics of meteorological variables at different time scales.  相似文献   

17.
18.
南京信息工程大学气候预测系统1.0版(NUIST CFS1.0)是基于日本海洋科学技术开发机构(JAMSTEC)的SINTEX-F模式发展而来,可以实现对全球气候异常的季节-年际预测。对过去近40 a的集合历史回报预测试验结果的评估发现,该预测系统对热带太平洋和印度洋海温异常具有良好的预测技巧,并且该系统能提前1.5~2 a对ENSO(Nino3.4指数)做出有技巧的预测(即相关系数达0.5),同时也可以提前1~2个季节对印度洋偶极子(IOD)做出有较高技巧的预测,展现了对主要热带气候信号的良好预测技巧。但是与国内外所有动力模式预测系统类似,该系统对东亚地区的气候异常预测还存在较大的不足。考虑到ENSO对东亚地区气候异常的强烈影响,本文尝试去除与ENSO预测相关的系统偏差来初步订正东亚地区夏季温度异常和降水距平百分率的预测结果。对比订正前后的结果表明,这一简单的订正方法有助于提高我国气候异常的预测准确率。同时选取2019年夏季气温异常和降水距平百分率的实时预测结果作为个例进行分析,发现订正能够提供一定的技巧改善,但与观测结果相比仍存在较大偏差,需要在今后的工作中不断改进完善。此外,本文也初步评估了NUIST CFS1.0对我国冬春季的气候预测技巧,并提供了经简单订正后的2019/2020年冬季和2020年春季的实时预测结果。  相似文献   

19.
A 15 member ensemble of 20th century simulations using the ECHAM4–T42 atmospheric GCM is utilized to investigate the potential predictability of interannual variations of seasonal rainfall over Africa. Common boundary conditions are the global sea surface temperatures (SST) and sea ice extent. A canonical correlation analysis (CCA) between observed and ensemble mean ECHAM4 precipitation over Africa is applied in order to identify the most predictable anomaly patterns of precipitation and the related SST anomalies. The CCA is then used to formulate a re-calibration approach similar to model output statistics (MOS) and to derive precipitation forecasts over Africa. Predictand is the climate research unit (CRU) gridded precipitation over Africa. As predictor we use observed SST anomalies, ensemble mean precipitation over Africa and a combined vector of mean sea level pressure, streamfunction and velocity potential at 850 hPa. The different forecast approaches are compared. Most skill for African precipitation forecasts is provided by tropical Atlantic (Gulf of Guinea) SST anomalies which mainly affect rainfall over the Guinean coast and Sahel. The El Niño/Southern Oscillation (ENSO) influences southern and East Africa, however with a lower skill. Indian Ocean SST anomalies, partly independent from ENSO, have an impact particularly on East Africa. As suggested by the large agreement between the simulated and observed precipitation, the ECHAM4 rainfall provides a skillful predictor for CRU precipitation over Africa. However, MOS re-calibration is needed in order to provide skillful forecasts. Forecasts using MOS re-calibrated model precipitation are at least as skillful as forecast using dynamical variables from the model or instantaneous SST. In many cases, MOS re-calibrated precipitation forecasts provide more skill. However, differences are not systematic for all regions and seasons, and often small.  相似文献   

20.
In projections of twenty-first century climate, Arctic sea ice declines and at the same time exhibits strong interannual anomalies. Here, we investigate the potential to predict these strong sea-ice anomalies under a perfect-model assumption, using the Max-Planck-Institute Earth System Model in the same setup as in the Coupled Model Intercomparison Project Phase 5 (CMIP5). We study two cases of strong negative sea-ice anomalies: a 5-year-long anomaly for present-day conditions, and a 10-year-long anomaly for conditions projected for the middle of the twenty-first century. We treat these anomalies in the CMIP5 projections as the truth, and use exactly the same model configuration for predictions of this synthetic truth. We start ensemble predictions at different times during the anomalies, considering lagged-perfect and sea-ice-assimilated initial conditions. We find that the onset and amplitude of the interannual anomalies are not predictable. However, the further deepening of the anomaly can be predicted for typically 1 year lead time if predictions start after the onset but before the maximal amplitude of the anomaly. The magnitude of an extremely low summer sea-ice minimum is hard to predict: the skill of the prediction ensemble is not better than a damped-persistence forecast for lead times of more than a few months, and is not better than a climatology forecast for lead times of two or more years. Predictions of the present-day anomaly are more skillful than predictions of the mid-century anomaly. Predictions using sea-ice-assimilated initial conditions are competitive with those using lagged-perfect initial conditions for lead times of a year or less, but yield degraded skill for longer lead times. The results presented here suggest that there is limited prospect of predicting the large interannual sea-ice anomalies expected to occur throughout the twenty-first century.  相似文献   

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