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1.
张丽霞  周天军  吴波  包庆 《气象学报》2008,66(6):968-981
文中评估了中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG/IAP)新一代耦合气候模式Fgoals_s1.1对热带降水年循环模态的模拟能力。通过与观测表层海温(SST)强迫的大气模式SAMIL试验结果比较,分析了海气耦合过程对年循环模态模拟效果的影响。结果表明Fgoals_s1.1能合理再现热带地区降水年循环模态的基本特征。Fgoals_s1.1模拟出了年平均降水场中的主要降水中心,但模拟的赤道和南太平洋降水偏多,而北太平洋降水则偏少。Fgoals_s1.1的季风模态降水呈现与观测一致的关于赤道反对称的特征,其模拟偏差大部分来自大气分量,尤其是在赤道外。Fgoals_s1.1的主要缺陷在于它对春秋非对称模态模拟能力低于单独大气模式,这主要是由于耦合模式模拟的SST距平的年循环位相与观测相反。SST纬向梯度的位相偏差使得太平洋沃克环流和印度洋的反沃克环流在春季强于秋季,最终导致模拟的春秋非对称模态的偏差。Fgoals_s1.1模拟的季风区范围接近观测,存在的问题在于模拟的西北太平洋季风区、东亚季风区都偏小。本文结果表明,大气模式偏差仅是Fgoals_s1.1在降水年循环模态模拟上的偏差的部分来源,改进模式模拟的SST,特别是赤道地区SST季节循环,是今后Fgoals_s1.1发展过程中急需解决的问题。  相似文献   

2.
本文基于观测和再分析资料,采用水汽收支诊断和合成分析方法,对新一代气候系统模式FGOALS-g3模拟的全球季风进行了系统评估,给出其较之前版本FGOALS-g2的优缺点,并通过与其大气分量模式GAMIL结果的比较,讨论了海气耦合过程的影响。结果表明,FGOALS-g3能合理再现全球季风气候态的基本特征,包括年平均、年循环模态、季风降水强度和季风区范围等,但模式低估陆地季风区年平均降水,高估海洋平均降水,模拟的热带地区春秋非对称模态偏强。研究指出FGOALS-g3模拟的陆地季风区范围偏小,这与模式模拟的夏季水汽垂直平流(尤其是热力项)偏小有关。年际变率上,FGOALS-g3能再现El Ni?o年全球季风降水偏少的整体特征,其不足之处在于部分季风区的降水异常存在一定偏差,例如其模拟的El Ni?o年西非季风区降水偏多和西南印度洋的偶极子型降水异常,均与观测分布不一致,且模式中西北太平洋季风区降水较观测偏多。这是由于El Ni?o年,模式中西非高层无弱辐合中心,且海洋性大陆较观测偏暖,对流中心西移。相较于FGOALS-g2,FGOALS-g3对环流、季风降水的年际变率和季风–ENSO关系的模...  相似文献   

3.
耦合模式FGOALS_s 模拟的亚澳季风年际变率及ENSO   总被引:10,自引:7,他引:3  
吴波  周天军  Tim Li  et al 《大气科学》2009,33(2):285-299
本文评估了中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室 (LASG/IAP) 新一代耦合气候模式FGOALS_s对亚澳季风和ENSO的模拟。结果表明, FGOALS_s可以模拟出亚澳季风的主要气候态特征。FGOALS_s模拟的ENSO事件振幅为观测值的70%, 同时它合理再现了ENSO周期的非规则性。FGOALS_s可以定性模拟出ENSO的主要空间特征。当赤道东太平洋SST升高时, 印度洋和西太平洋海表面气压升高, 而东太平洋海表面气压降低。FGOALS_s的主要缺陷在于模拟的ENSO峰值多出现在春季和夏季。与ENSO振幅偏小相反, FGOALS_s模拟的亚澳季风年际变率振幅大于观测。但是观测中亚澳季风年际变率与ENSO暖位相的显著负相关关系, 在模式中没有得到合理再现, 原因部分可归之于耦合模式在ENSO锁相模拟上的缺陷。由于模式模拟的ENSO峰值出现在北半球春季和夏季, Walker环流异常下沉支移动到西北太平洋, 其激发出的异常反气旋位置较之观测要偏东, 导致印度季风降水和El Niño的负相关关系不显著; 在北半球冬季, 由于模式中的赤道东太平洋SST暖异常较弱, 亚澳季风响应也偏弱。此外, 由于赤道东太平洋SST异常向西伸展, 观测中位于澳洲季风区的辐散中心向西偏移, 最终导致模式中澳洲季风降水与ENSO的负相关同样不显著。  相似文献   

4.
利用1979—2005年OAFlux (Objectively Analyzed air-sea Fluxes) 观测资料以及CMIP5的15个耦合模式的模拟结果,评估了BCC_CSM1.1(m) 模式对热带太平洋年平均潜热通量气候态和变化趋势的模拟能力,并分析造成趋势偏差的可能原因。结果表明:BCC_CSM1.1(m) 模式模拟热带太平洋年平均潜热通量气候态在各纬度上差异较大, 其中在赤道的模拟能力较佳,而在10°N和8°S附近模拟偏差较大;BCC_CSM1.1(m) 模式对热带太平洋年平均潜热通量趋势的模拟能力一般,造成趋势偏差的主要原因是该模式低估了风速对潜热通量的局地贡献以及它对风速的非局地贡献的模拟存在较大偏差。此外,该模式未能较好地模拟出风速对全球变暖响应。因此,BCC_CSM1.1(m) 模式对热带太平洋年平均潜热通量趋势模拟的改进需加强其对风速模拟的改进。  相似文献   

5.
较全面地介绍了北京气候中心气候系统模式(BCC_CSM)研发所取得的一些进展及其在气候变化研究中的应用,重点介绍了全球近280 km较低分辨率的全球海-陆-气-冰-生物多圈层耦合的气候系统模式BCC_CSM1.1和110 km中等大气分辨率的BCC_CSM1.1(m),以及大气、陆面、海洋、海冰各分量模式的发展。BCC_CSM1.1和BCC_CSM1.1(m)气候系统模式均包含了全球碳循环和动态植被过程。当给定全球人类活动导致的碳源排放后,就可以模拟和预估人类活动对气候变化的影响。BCC_CSM1.1和BCC_CSM1.1(m)已应用于IPCC AR5模式比较,为中外开展气候变化机理分析和未来气候变化预估提供了大量的试验数据。还介绍了BCC_CSM1.1和BCC_CSM1.1(m)参与国际耦合模式比较计划(CMIP5)的大量试验分析评估结果,BCC_CSM能够较好地模拟20世纪气温和降水等气候平均态和季节变化特征,以及近1000年的历史气候变化,所预估的未来100年气候变化与国际上其他模式的CMIP5试验预估结果相当。初步的分析表明,分辨率相对高的BCC_CSM1.1(m)在区域气候平均态的模拟上优于分辨率较低的BCC_CSM1.1。  相似文献   

6.
利用CWRF模式(Climate-Weather Research and Forecasting model)对国家气候中心BCC_CSM1.1m业务预测模式短期气候预测结果进行中国区域降尺度,并使用1991—2010年3—8月逐日气温降水观测数据评估预测能力。结果表明:CWRF预测地面2 m气温、降水气候平均态的空间分布比BCC_CSM1.1m更接近观测,分布误差更小;在保持总体技巧不低于BCC_CSM1.1m的同时,CWRF对我国华东和华中地区的降水年际变化预测准确率更高;对不同强度的降水预测CWRF表现均优于BCC_CSM1.1 m模式,尤其在极端降水预测准确率上更优。总之,得益于更高的空间分辨率和优化的低空物理过程模拟,CWRF降尺度可以提高中国夏季跨季度降水预测能力。  相似文献   

7.
BCC大气环流模式对亚澳季风年际变率主导模态的模拟   总被引:8,自引:3,他引:5  
王璐  周天军  吴统文  吴波 《气象学报》2009,67(6):973-982
利用观测海温驱动下的北京气候中心大气环流模式(BCC-AGCM)1979-2000年的模拟数据,从亚澳季风(A-AM)年际变率的角度,对该模式的性能进行了分析.通过季节依赖的EOF分析方法(SEOF)得到观测第1模态,与ENSO从暖位相向冷位相的转变相联系,并伴随东南印度洋和西北太平洋的降水异常随季节变化.该模态具有准2a和4-6a周期的谱峰.分析结果显示,BCC模式可以很好地模拟出第1模态的时间变化特征,及其与ENSO位相的同步关系.但是,模式模拟的降水空间型与观测存在偏差,这主要是由于模式对环流场模拟的偏差造成的,具体表现在西北太平洋(WNP)反气旋和南印度洋(SIO)反气旋的季节锁相模拟偏差.前者与模式模拟的环流场整体偏东有关,后者是由于SIO反气旋的发展和衰亡过程受印度洋局地海气相瓦作用影响,而单独大气模式则无法合理地反映这一过程.另外,模式模拟的第一模态降水空间型在夏季效果较差,原因在于模式模拟的夏季平均降水量存在偏差,尤其是东南印度洋的降水量模拟偏少.进一步分析表明,这可能与对流参数化方案的选择有关.  相似文献   

8.
黄昕  周天军  吴波  陈晓龙 《大气科学》2019,43(2):437-455
本文通过与观测和再分析资料的对比,评估了LASG/IAP发展的气候系统模式FGOALS的两个版本FGOALS-g2和FGOALS-s2对南亚夏季风的气候态和年际变率的模拟能力,并使用水汽收支方程诊断,研究了造成降水模拟偏差的原因。结果表明,两个模式夏季气候态降水均在陆地季风槽内偏少,印度半岛附近海域偏多,在降水年循环中表现为夏季北侧辐合带北推范围不足。FGOALS-g2中赤道印度洋"东西型"海温偏差导致模拟的东赤道印度洋海上辐合带偏弱,而FGOALS-s2中印度洋"南北型"海温偏差导致模拟的海上辐合带偏向西南。水汽收支分析表明,两个模式中气候态夏季风降水的模拟偏差主要来自于整层积分的水汽通量,尤其是垂直动力平流项的模拟偏差。一方面,夏季阿拉伯海和孟加拉湾的海温偏冷而赤道西印度洋海温偏暖,造成向印度半岛的水汽输送偏少;另一方面,对流层温度偏冷,冷中心位于印度半岛北部对流层上层,同时季风槽内总云量偏少,云长波辐射效应偏弱,对流层经向温度梯度偏弱以及大气湿静力稳定度偏强引起的下沉异常造成陆地季风槽内降水偏少。在年际变率上,观测中南亚夏季风环流和降水指数与Ni?o3.4指数存在负相关关系,但FGOALS两个版本模式均存在较大偏差。两个模式中与ENSO暖事件相关的沃克环流异常下沉支和对应的负降水异常西移至赤道以南的热带中西印度洋,沿赤道非对称的加热异常令两个模式中越赤道环流季风增强,导致印度半岛南部产生正降水异常。ENSO相关的沃克环流异常下沉支及其对应的负降水异常偏西与两个模式对热带南印度洋气候态降水的模拟偏差有关。研究结果表明,若要提高FGOALS两个版本模式对南亚夏季风气候态模拟技巧,需减小耦合模式对印度洋海温、对流层温度及云的模拟偏差;若要提高南亚夏季风和ENSO相关性模拟技巧需要提高模式对热带印度洋气候态降水以及与ENSO相关的环流异常的模拟能力。  相似文献   

9.
利用1991-2017年BCC_CSM1.1(m)模式模拟数据和NCEP/NCAR逐月再分析资料,评估了BCC_CSM1.1(m)对初夏东北冷涡的模拟能力。结果表明:BCC_CSM1.1(m)模式可以对500 hPa位势高度场气候态进行模拟,均方根误差显示该模式对中国东北南部地区500 hPa位势高度场的模拟要优于东北北部地区。EOF第一模态结果显示,该模式可以较好地模拟出500 hPa位势高度场的主要时空变化特征。BCC_CSM1.1(m)模式能够模拟出近27 a东北冷涡指数的上升趋势和年际变化,但模拟的上升趋势较实况偏强,年际变率较实况偏弱。BCC_CSM1.1(m)模式能够模拟出东北冷涡指数的年代际突变,但是对突变开始时间的模拟较实况偏晚。BCC_CSM1.1(m)模式能够模拟出东北冷涡指数和500 hPa位势高度场在东北及其附近地区的显著正相关,不能模拟出东北冷涡指数与东北初夏降水之间的显著负相关。此外,模式东北冷涡指数对东北初夏降水的预测能力十分有限。  相似文献   

10.
将可变网格大气环流模式LMDZ的模拟中心移动至中国地理中心附近(37°N,112.5°E),在东亚地区进行加密,使用其对应全球模式同步输出资料进行环流强迫,以观测海表温度SST和海冰SIC资料对下边界强迫,对1979-2008年各年5-9月对500 hPa高度场,850 hPa温度场和地面要素等进行了模拟,并利用同期的NCEP/NCAR再分析资料和由中国气象台站资料生成的格点资料,评估该模式对东亚地区高空环流场、西太平洋副热带高压及地面温度、降水等的夏季气候平均态的模拟能力.结果表明:LMDZ可以较好的模拟平均环流场,其模拟结果能够反映实际的500 hPa高度场和850 hPa温度场的分布特征和趋势,但总体模拟值较观测值偏低;对副高强度的模拟能力偏弱、模拟的副高位置偏东,但准确的表现了副高随时间变化的移动特性;模式较好的再现了中国区域夏季地面气温和降水的空间分布特征;但从数值吻合度看,温度模拟主要呈区域性偏冷距平,在东南沿海地区偏低1~3℃,在西部青藏高原地区偏低3~4℃及以上,中部和东北大部基本无偏差;降水的模拟在中国西北地区与实际观测较为一致,其误差主要表现为在中国东南部沿海模拟的降水偏多;对7个子区域,模式对850 hPa温度场和地面日均气温的再现能力优于对500 hPa高度场的模拟,且子区域间模拟偏差结果相差大,其中华北区地面气温模拟偏差最小,西北区降水值模拟偏差最小.  相似文献   

11.
This paper evaluates the performance of a coupled general circulation model FGOALS_s1.1 developed by LASG/IAP in simulating the annual modes of tropical precipitation.To understand the impacts of air-sea coupling on the annual modes,the result of an off-line simulation of the atmospheric component of FGOALS_s1.1,i.e.,LASG/IAP atmospheric general circulation model SAMIL,is also analyzed.FGOALS_s1.1 can reasonably reproduce major characteristics of the annual mean precipitation.Nonetheless,the coupled model shows overestimation of precipitation over the equatorial Pacific and tropical South Pacific,and underestimation of precipitation over the northern equatorial Pacific.The monsoon mode simulated by FGOALS_s1.1 shows an equatorial anti-symmetric structure,which is consistent with the observation.The bias of the coupled model in simulating monsoon mode resembles that of SAMIL,especially over the subtropics.The main deficiency of FGOALS_s1.1 is its failure in simulating the spring-fall asymmetric mode.This is attributed to the false phase of sea surface temperature anomaly (SSTA) annual cycleover the equatorial central-castern Pacific and Indian Ocean,which leads to the bias of the Walker circulation over the equatorial Pacific and the anti-Walker circulation over the Indian Ocean in boreal spring and fall.In addition,the domains of the western North Pacific monsoon and Indian monsoon simulated by the coupled model are smaller than the observation.The study suggests that the bias of the fully coupled oceanatmosphere model can only be partly attributed to the bias of the atmospheric component.The performance of FGOALS-s1.1 in simulating the annual cycle of equatorial SST deserves further improvement.  相似文献   

12.
The summer Asian–Pacific Oscillation(APO) is a major teleconnection pattern that reflects the zonal thermal contrast between East Asia and the North Pacific in the upper troposphere. The performance of Beijing Climate Center Climate System Models(BCC CSMs) with different horizontal resolutions, i.e., BCC CSM1.1 and BCC CSM1.1(m), in reproducing APO interannual variability, APO-related precipitation anomalies, and associated atmospheric circulation anomalies, is evaluated.The results show that BCC CSM1.1(m) can successfully capture the interannual variability of the summer APO index. It is also more capable in reproducing the APO's spatial pattern, compared to BCC CSM1.1, due to its higher horizontal resolution. Associated with a positive APO index, the northward-shifted and intensified South Asian high, strengthened extratropical westerly jet, and tropical easterly jet in the upper troposphere, as well as the southwesterly monsoonal flow over North Africa and the Indian Ocean in the lower troposphere, are realistically represented by BCC CSM1.1(m), leading to an improvement in reproducing the increased precipitation over tropical North Africa, South Asia, and East Asia, as well as the decreased precipitation over subtropical North Africa, Japan, and North America. In contrast, these features are less consistent with observations when simulated by BCC CSM1.1. Regression analysis further indicates that surface temperature anomalies over the North Pacific and the southern and western flanks of the Tibetan Plateau are reasonably reproduced by BCC CSM1.1(m), which contributes to the substantial improvement in the simulation of the characteristics of summer APO compared to that of BCC CSM1.1.  相似文献   

13.
Long-lead precipitation forecasts for 1–4 seasons ahead are usually difficult in dynamical climate models due to the model deficiencies and the limited persistence of initial signals. But, these forecasts could be empirically improved by statistical approaches. In this study, to improve the seasonal precipitation forecast over the southern China (SC), the statistical downscaling (SD) models are built by using the predictors of atmospheric circulation and sea surface temperature (SST) simulated by the Beijing Climate Center Climate System Model version 1.1 m (BCC_CSM1.1 m). The different predictors involved in each SD model is selected based on both its close relationship with the target seasonal precipitation and its reasonable prediction skill in the BCC_CSM1.1 m. Cross and independent validations show the superior performance of the SD models, relative to the BCC_CSM1.1 m. The temporal correlation coefficient of SD models could reach > 0.4, exceeding the 95 % confidence level. The SC precipitation index can be much better forecasted by the SD models than by the BCC_CSM1.1 m in terms of the interannual variability. In addition, the errors of the precipitation forecast in all four seasons are significantly reduced over most of SC in the SD models. For the 2015/2016 strong El Niño event, the SD models outperform the dynamical BCC_CSM1.1 m model on the spatial and regional-average precipitation anomalies, mostly due to the effective SST predictor in the SD models and the weak response of the SC precipitation to El Niño-related SST anomalies in the BCC_CSM1.1 m.  相似文献   

14.
不同水平分辨率BCC_CSM模式对中亚地面气温模拟能力评估   总被引:2,自引:1,他引:1  
本研究基于IPCC AR5(Intergovernmental Panel on Climate Change:Fifth Assessment Report)中BCC_CSM1.1(Beijing Climate Center Climate System Model version 1.1)和BCC_CSM1.1(m)(Beijing Climate Center Climate System Model version 1.1 with a Moderate Resolution)气候模式的历史试验结果和CRU(Climatic Research Unit)资料, 采用趋势分析和滑动平均等方法检验了两个版本BCC_CSM模式对中亚地区1948~2011年平均地表气温、各热通量及其趋势的模拟性能, 并讨论了不同模式水平分辨率的影响, 结果显示:BCC_CSM1.1和BCC_CSM1.1(m)两个模式均能够模拟出中亚地区显著增温以及感热通量、长/短波净辐射等要素由南向北递减的总体趋势。其中, BCC_CSM1.1(m) 在对中亚地面年平均气温、感热通量和长/短波净辐射空间分布的模拟结果好于BCC_CSM1.1, 但对于气温标准差的模拟, BCC-CSM1.1模式略好于BCC-CSM1.1(m)。模式分辨率的提高, 能够更好地表现出地形的影响, 对气温和各热通量模拟性能改善较大, 在中亚地区年平均气温的模拟中表现出了一定的优势。  相似文献   

15.
Previous studies have revealed a combination mode(C-mode) occurring in the Indo-Pacific region,arising from nonlinear interactions between ENSO and the western Pacific warm pool annual cycle.This paper evaluates the simulation of this C-mode and its asymmetric SST response in Had GEM3 and its resolution sensitivity using three sets of simulations at horizontal resolutions of N96,N216 and N512.The results show that Had GEM3 can capture well the spatial pattern of the C-mode associated surface wind anomalies,as well as the asymmetric response of SST in the tropical Pacific,but it strongly overestimates the explained variability of the C-mode compared to the ENSO mode.The model with the three resolutions is able to reproduce the distinct spectral peaks of the C-mode at the near annual combination frequencies,but the performance in simulating the longer periods is not satisfactory,presumably due to the unrealistic simulation of the ENSO mode.Increasing the horizontal resolution can improve the consistency between atmospheric and oceanic representations of the C-mode,but not necessarily enhance the accuracy of C-mode simulation compared with observation.  相似文献   

16.
This paper reviews recent progress in the development of the Beijing Climate Center Climate System Model(BCC-CSM) and its four component models(atmosphere,land surface,ocean,and sea ice).Two recent versions are described:BCC-CSM1.1 with coarse resolution(approximately 2.8125°×2.8125°) and BCC-CSM1.1(m) with moderate resolution(approximately 1.125°×1.125°).Both versions are fully coupled climate-carbon cycle models that simulate the global terrestrial and oceanic carbon cycles and include dynamic vegetation.Both models well simulate the concentration and temporal evolution of atmospheric CO_2 during the 20th century with anthropogenic CO2 emissions prescribed.Simulations using these two versions of the BCC-CSM model have been contributed to the Coupled Model Intercomparison Project phase five(CMIP5) in support of the Intergovernmental Panel on Climate Change(IPCC) Fifth Assessment Report(AR5).These simulations are available for use by both national and international communities for investigating global climate change and for future climate projections.Simulations of the 20th century climate using BCC-CSMl.l and BCC-CSMl.l(m) are presented and validated,with particular focus on the spatial pattern and seasonal evolution of precipitation and surface air temperature on global and continental scales.Simulations of climate during the last millennium and projections of climate change during the next century are also presented and discussed.Both BCC-CSMl.l and BCC-CSMl.l(m) perform well when compared with other CMIP5 models.Preliminary analyses indicate that the higher resolution in BCC-CSM1.1(m) improves the simulation of mean climate relative to BCC-CSMl.l,particularly on regional scales.  相似文献   

17.
Since the interaction between atmospheric synoptic eddy(SE)(2–8 days) activity and low-frequency(LF)(monthly)flow(referred to as SELF) plays an essential role in generating and maintaining dominant climate modes,an evaluation of the performance of BCC_CSM1.1(m) in simulating the SE feedback onto the LF flow is given in this paper.The model captures well the major spatial features of climatological eddy vorticity forcing,eddy-induced growth rate,and patterns of SELF feedback for the climate modes with large magnitudes in cold seasons and small magnitudes in warm seasons for both the Northern and Southern Hemisphere.As in observations,the eddy-induced growth rate and SELF feedback patterns in the model also show positive SE feedback.Overall,the relationships between SE and LF flow show that BCC_CSM1.1(m)satisfactorily captures the basic features of positive SE feedback,which demonstrates the simulation skill of the model for LF variability.Specifically,such an evaluation can help to find model biases of BCC_CSM1.1(m) in simulating SE feedback,which will provide a reference for the model's application.  相似文献   

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