国家气候中心短期气候预测模式系统业务化进展

该文简要介绍了国家气候中心短期气候预测模式系统的研发成果,并侧重于从海洋资料同化系统、陆面资料同化系统、月动力延伸预测模式系统、季节气候预测模式系统4个方面介绍了第2代短期气候预测模式系统的业务化进展。第2代海洋资料同化系统已初步建成,其对温盐的同化效果总体上优于第1代同化系统;陆面资料同化系统正在研发中,目前已完成其中的多源降水融合子系统的业务建设工作,可为陆面分量提供实时的大气降水强迫分析场;第2代月动力延伸预测系统基于国家气候中心大气环流模式BCC_AGCM2.2建立,已于2012年8月进入准业务运行阶段;第2代季节预测模式系统基于国家气候中心气候系统模式BCC_CSM1.1(m)建立,将于2013年底投入准业务运行。初步评估表明:第2代月动力延伸预测模式系统和季节气候预测模式系统分别对候、旬、月和季节、年际时间尺度的气候变率体现出了一定的预测能力,其对降水、气温、环流等要素的预测技巧总体上要高于第1代预测系统。

BCC第二代气候预测模式系统对2015年一次寒潮过程的预报能力评估

利用BCC第二代气候预测模式系统(BCC_CSM2)的回报试验结果,评估了BCC_CSM2对2015年1月27—31日一次强寒潮过程的次季节预报能力,结果表明:(1)此次寒潮过程主要由新地岛以西的短波槽不断东移发展而形成的,模式能够提前10 d较好地预报过程期间降温以及高空环流形势,相关系数、距平符号一致率以及均方根误差都定量表明模式在10 d左右具有较好的预报能力,但是对降温程度的预报能力随起报时间的延长逐渐降低;(2)为了探讨随起报时间延长模式预报能力降低的原因,从位势倾向方程出发,分析相对涡度平流和温度平流随高度变化发现,在模式提前10 d之内的预报时段内,模式预报的相对涡度平流和温度平流随高度变化与再分析资料的诊断结果基本一致,能够合理预测短波槽的东移和槽脊的强度变化,当预报超过10 d后,模式中相对涡度平流的配置不利于短波槽的东移,模式预报的低层出现暖平流,并随高度增加而减小,不利于槽的加深,使模式预报的环流形势产生偏差,导致模式预报能力降低。

第2代季节气候预测模式系统对东北夏季降水预测能力分析

简要分析了第2代季节气候预测模式系统在东北夏季累计降水量的预测能力,结果表明:模式数据与观测值空间分布较一致,数值较观测值偏小,波动程度低。辽宁地区夏季累计降水量距平百分率模式与观测结果相关性较高,东北中部地区较差。季节气候预测模式系统具有一定的预测能力,但准确率有待进一步加强。

MODES系统对贵州月气温、降水预测初步评估

通过对2013年1月—2015年6月(MODES)发布的最优月预测产品在贵州省月平均气温距平和降水距平百分率的预测检验评估,发现MODES对全省平均气温有较好的预报,分析时段内预测与实况的相关系数为0.24,距平同号率为65.5%,且对气温偏高预测的可参考性高于其对气温偏低的预测。相比于气温,MODES对降水预测能力较弱,参考性也相对较低,其中对贵州全省平均降水偏多趋势的预测技巧要优于对全省平均偏少趋势的预报技巧。逐站分析显示,MODES对贵州气温预测效果较好的地区在西部、北部和东部,对降水偏多的预测效果较好的地区位于除西北部和北部边缘地区外的其余大部地区。通过对MODES与预报员综合预报的结果评估发现,MODES月预测总体效果较预报员好,且稳定性高于预报员,可为预报员提供参考信息。

预测微生物学在食品品质和安全评估上的运用

食品品质和安全与人们的生活息息相关,预测微生物学应消费者对食品的要求日趋天然、多样和安全发展起来的微生物学研究新领域,是通过对食品中各种微生物的基本特征及其受各种因子影响程度的研究,建立微生物数据库,使用计算机建模程序建立微生物生长、残存、死亡的数学模型,不进行微生物检测分析,运用模型快速对微生物的动态进行预测.

Climate Change over China in the 21st Century as Simulated by BCC_CSM1.1-RegCM4.0

Driven by the global model,Beijing Climate Center Climate System Model version 1.1(BCC_CSM1.1),climate change over China in the 21st century is simulated by a regional climate model(RegCM4.0)under the new emission scenarios of the Representative Concentration Pathways—RCP4.5 and RCP8.5.This is based on a period of transient simulations from 1950 to2099,with a grid spacing of 50 km.The present paper focuses on the annual mean temperature and precipitation in China over this period,with emphasis on their future changes.Validation of model performance reveals marked improvement of the RegCM4.0 model in reproducing present day temperature and precipitation relative to the driving BCC_CSM1.1 model.Significant warming is simulated by both BCC_CSM1.1 and RegCM4.0,however,spatial distribution and magnitude differ between the simulations.The high emission scenario RCP8.5 results in greater warming compared to RCP4.5.The two models project different precipitation changes,characterized by a general increase in the BCC_CSM1.1,and broader areas with decrease in the RegCM4.0 simulations.

MJO ensemble prediction in BCC-CSM1.1(m)using different initialization schemes

The Madden–Julian Oscillation（MJO）is a dominant mode of tropical intraseasonal variability（ISV）and has prominent impacts on the climate of the tropics and extratropics.Predicting the MJO using fully coupled climate system models is an interesting and important topic.This paper reports upon a recent progress in MJO ensemble prediction using the climate system model of the Beijing Climate Center,BCC-CSM1.1（m）;specifically,the development of three different initialization schemes in the BCC ISV/MJO prediction system,IMPRESS.Three sets of 10-yr hindcasts were separately conducted with the three initialization schemes.The results showed that the IMPRESS is able to usefully predict the MJO,but is sensitive to the initialization scheme used and becomes better with the initialization of moisture.In addition,a new ensemble approach was developed by averaging the predictions generated from the different initialization schemes,helping to address the uncertainty in the initial values of the MJO.The ensemble-mean MJO prediction showed significant improvement,with a valid prediction length of about 20 days in terms of the different criteria,i.e.,a correlation score beyond 0.5,a RMSE lower than 1.414,or a mean square skill score beyond 0.This study indicates that utilizing the different initialization schemes of this climate model may be an efficient approach when forming ensemble predictions of the MJO.

An Effective Approach for Improving the Real-Time Prediction of Summer Rainfall over China

This paper has two purposes. One is to evaluate the ability of an atmospheric general circulation model (IAP9L-AGCM) to predict summer rainfall over China one season in advance. The other is to propose a new approach to improve the predictions made by the model. First, a set of hindcast experiments for summer climate over China during 1982-2010 are performed from the perspective of real-time prediction with the IAP9L-AGCM model and the IAP ENSO prediction system. Then a new approach that effectively combines the hind-cast with its correction is proposed to further improve the model's predictive ability. A systematic evaluation reveals that the model's real-time predictions for 41 stations across China show significant improvement using this new approach, especially in the lower reaches between the Yellow River and Yangtze River valleys.

High-Resolution Hindcast of Record-Breaking Rainfall in Beijing and Impact of Topography

In this paper,a hindcast study of the record-breaking rainfall event occurring in Beijing on 21July 2012,is conducted by using the Weather Research and Forecasting(WRF)model forced by National Centers for Environmental Prediction(NCEP)Global Forecasting System(GFS)outputs,paired with an investigation of the impact of topography in this region.The results indicate that WRF can reasonably predict the salient features of orographic precipitation;the 24-h rainfall amount and spatial distribution compare reasonably well with the observations.The hindcast simulation also indicates that rainfall events can be predicted approximately 36 h ahead.When the topography is removed,the spatial distribution of rainfall changes remarkably,suggesting the importance of the topography in determining rainfall structure.These results also indicate that prediction of such city-scale heavy rainfall events would benefit from a high-resolution prediction system.

Projected Climate Change in the Northwestern Arid Regions of China: An Ensemble of Regional Climate Model Simulations

The projected temperature and precipitation- change under different emissions scenarios using Coupled Model Intercomparison Project Phase 5 models over the northwestern arid regions of China （NWAC） were ana- lyzed using the ensemble of three high-resolution dy- namical downscaling simulations： the simulation of the Regional Climate Model version 4.0 （RegCM4） forced by the Beijing Climate Center Climate System Model version 1.1 （BCC_CSMI.1）; the Hadley Centre Global En- vironmental Model version 3 regional climate model （HadGEM3-RA） forced by the Atmosphere-Ocean cou- pled HadGEM version 2 （HadGEM2-AO）; and the Weather Research and Forecasting （WRF） model forced by the Norwegian community Earth System Model （NorESM1-M）. Model validation indicated that the mul- timodel simulations reproduce the spatial and temporal distribution of temperature and precipitation well. The temperature is projected to increase over NWAC under both the 4.5 and 8.5 Representative Concentration Path- ways scenarios （RCP4.5 and RCP8.5, respectively） in the middle of the 21 st century, but the warming trend is larger under the RCP8.5 scenario, Precipitation shows a signifi- cant increasing trend in spring and winter under both RCP4.5 and RCPS.5; but in summer, precipitation is pro- jected to decrease in the Tarim Basin and Junggar Basin. The regional averaged temperature and precipitation show increasing trends in the future over NWAC; meanwhile, the large variability of the winter mean temperature and precipitation may induce more extreme cold events and intense snowfall events in these regions in the future.

Study of Commercial Bank Risk Monitoring Model in Individual Consumption Credit

With the development of individual consumption credit (ICC) in China, commercial banks have been exposed to more and more risks. The loan failure has been an important problem that the banking must face and revolve. This paper develops a factor system to explain how the borrower's risk is affected, and then establishes a risk monitoring model with AHP to pre-warn the banks how much the risk is.

Design and testing of a global climate prediction system based on a coupled climate model

A global climate prediction system （PCCSM4） was developed based on the Community Climate System Model, version 4.0, developed by the National Center for Atmospheric Research （NCAR）, and an initialization scheme was designed by our group. Thirty-year （1981-2010） one-month-lead retrospective summer climate ensemble predictions were carded out and analyzed. The results showed that PCCSM4 can efficiently capture the main characteristics of JJA mean sea surface temperature （SST）, sea level pressure （SLP）, and precipitation. The prediction skill for SST is high, especially over the central and eastern Pacific where the influence of E1 Nino-Southem Oscillation （ENSO） is dominant. Temporal correlation coefficients between the pre- dicted Nino3.4 index and observed Nino3.4 index over the 30 years reach 0.7, exceeding the 99% statistical significance level. The prediction of 500-hPa geopotential height, 850-hPa zonal wind and SLP shows greater skill than for precipitation. Overall, the predictability in PCCSM4 is much higher in the tropics than in global terms, or over East Asia. Furthermore, PCCSM4 can simulate the summer climate in typical ENSO years and the interannual variability of the Asian summer monsoon well. These preliminary results suggest that PCCSM4 can be applied to real-time prediction after further testing and improvement.

DESIGN OF CONTROL INVARIANT SETS OF PLANAR SYSTEMS

Control invariant sets play a key role in model predictive control.Using Lyapunov function,a technique is proposed to design control invariant sets of planar systems in a precise form.First,itis designed for a linear system in Brunovsky canonical form.Then,the result is extended to generallinear systems.Finally,the nonlinear control systems are considered,and some sufficient conditionsand design techniques are also obtained.Numerical examples are presented to illustrate the proposeddesign methods.