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1.
我国近年来短期气候预测研究的若干进展   总被引:5,自引:4,他引:5       下载免费PDF全文
回顾了近年来我国短期气候预测研究的若干进展,主要是在中国科学院大气物理研究所完成的以气候模式为基础的短期气候预测方面工作.第一个基于气候数值模式开展短期气候预测试验的是曾庆存等人,他们所采用的是IAP AGCM耦合一个热带太平洋环流模式(OGCM);1997年,基于耦合气候模式基础上的ENSO预测系统建立起来;同时开展了东亚区气候可预测性研究;利用气候变动的准两年信号提出了对模式预测结果进行有效修正的方案;为了考虑初始土壤湿度异常对夏季气候的影响,建立了气象变量和土壤湿度的经验关系;还系统地研究了1998年海面温度异常和大气春季异常对夏季气候(特别是发生于中国的大水)预测的影响.  相似文献   

2.
大气初始异常在跨季度短期气候预测中作用的研究   总被引:4,自引:0,他引:4  
针对大气初始异常在跨季度短期气候预测中的可能作用,利用中国科学院大气物理研究所9层大气环流格点模式(简称IAP 9L-AGCM)对全球夏季气候进行了30年(1970~1999年)集合回报试验,系统地考察了基于大气初始异常条件下模式对跨季度短期气候异常的可预测性.结果表明,在热带、副热带及高纬都存在气候异常的可预测性区域,说明大气初始场异常本身对跨季度短期气候预测有很重要的影响.相对于全球来说,大气初始异常对跨季度短期气候预测的影响在东亚地区更为显著,其作用不可忽略.通过对典型年份的个例分析发现,在某些气候异常剧烈的特殊年份,春季大气初始异常在我国夏季气候形成中扮演着尤为重要的角色.  相似文献   

3.
跨季度气候距平数值预测试验   总被引:35,自引:19,他引:35  
本文报导我们用海气耦合模式所进行的两次跨季度气候距平数值预测试验:一次由1988年秋季(9月)开始预测至翌年初夏(5月),另一次由隆冬(1989年1月)开始预测至8月,预测时效均超过半年,其结果是令人鼓舞的。 我们经过分析认为,作跨季度气候预测必须用耦合模式。本试验中我们采用大气物理研究所的大气环流模式和大洋环流模式,其中的大气环流模式能较好地模拟出全球气候状态,尤其是夏季形势及东亚季风区的季节突变现象;大洋环流模式消除了“刚盖近似”,模拟得到的海表层洋流、水温及海表热通量、上层海洋热贮存率等都比较接近实况。在进行耦合积分时,初条件取自观测得到的月平均大气环流资料和海表温度场(SST)及经协调性积分后的模式海候场,采用海洋、大气非同步耦合方案;同时,对海气相互作用各项进行订正,以消除模式气候场和海候场的系统性偏差。 这两次试验的初始场反映出太平洋有大范围和较强的海表温度距平(SSTA),是典型的La Nino(即反E1 Nino)现象。试验结果表明:环流形势季节转换、SSTA的维持及演变(如1989年5月以后La Nino的终止)、东亚地区各月和季度降水距平等大形势分布的预测都可以说是成功的。这似乎说明,当有较大范围和较强的大气或海洋环流形势异常(如SSTA)时,包括环流异常演变和降水距平在内的跨季节预测是可能的,但要达到实用地步,模式以及耦合方案须大加改进,观测系统也应完善,四维分析(尤其是用于海洋环流的资料同化)方法也要研究。此外,用耦合模式作出的数值预测同由统计方法、相似方法以及其它天气-气候分析研究所得到的预报因子等结合起来,作跨季度的降水距平预测也许更为有效。 另外,我们还在本试验中,用数值模拟方法进行了跨季度降水异常机理研究,肯定了一些天气-气候分析研究所得到的结论。  相似文献   

4.
袁重光 《大气科学》1990,14(2):249-256
本文回顾了用大气环流模式及大气-海洋耦合模式进行短期气候预测试验研究的进展情况,综述了试验研究得出的一些初步结论,文中也介绍了我国在这方面进行的一些初步试验研究的结果,供短期气候预测研究工作的参考。  相似文献   

5.
利用ARGO资料改进ENSO和我国夏季降水气候预测   总被引:7,自引:2,他引:7       下载免费PDF全文
全球海洋ARGO资料的获取为气候预测的研究提供了前所未有的海洋资料。该文首先利用ARGO资料改进次表层参数化方案后的Zebiak-Cane海洋模式, 与统计大气模式耦合, 建立了热带动力海洋-统计大气耦合模式。通过比较应用和未应用ARGO资料改进的海洋模式, 进行了耦合模式的长期回报试验。结果表明:ARGO资料的应用极大地改善了耦合模式对热带太平洋海面温度异常的预测能力, 提前3个月和6个月的回报结果都有很大的改进, 基本上回报出了Ni?o3.4区海面温度异常的演变特征, 对厄尔尼诺和拉尼娜都能够给出较准确的回报, 回报结果与观测之间的相关性在整个热带太平洋区域明显提高。该文还利用国家气候中心 (NCC) 全球海气耦合模式, 对我国夏季降水进行了个例和多年季度回报模拟试验, 探讨了包含和不包含ARGO观测资料的同化资料作为初始场对我国夏季降水预测的影响, 表明采用带有ARGO观测资料的海洋同化初始场, 回报的我国夏季降水分布形式与观测更一致, 回报结果与观测之间的正相关区域变大, 对我国夏季降水的回报水平比采用没有ARGO观测资料的海洋同化初始场时有明显提高。  相似文献   

6.
土壤湿度初始异常对东亚区域气候模拟影响的敏感性试验   总被引:1,自引:0,他引:1  
利用耦合了CLM3.5陆面模式的区域气候模式RegCM4.0,通过敏感性试验,探讨了人为减小春季初始土壤体积水含量对短期时间尺度东亚夏季气候模拟的可能影响。结果表明:较低的初始土壤湿度场能够明显改变区域的地表能量平衡,引起地表净长波辐射和感热通量的显著增加,进而加强了地表对大气的加热,因而引起东亚大范围地区特别是中国东部、印度北部和中亚地区地表温度、气温的升高。与气温不同,初始土壤湿度场对降水的影响很小而且有较大的不确定性,同时偏暖的下垫面使得对流层中高层出现暖高压异常,但这些影响均不显著。综合来看,土壤湿度初始场的初始异常,对RegCM4.0 模式东亚气候模拟的结果有一定影响,特别是在地表温度、气温和能量平衡方面,应在以后的模拟中加以考虑。  相似文献   

7.
赵彦  林朝晖  李旭  袁重光 《大气科学》2000,24(2):215-222
利用中国科学院大气物理研究所研制的短期气候距平数值预测系统(IAP PSSCA),  种版本的大气环流模式:AGCM 1.1和AGCM 1.2,分别以2月11~19日的9天大气观测值为初始场,以给定海温为边界场,对1980~1994年的15年的降水异常进行了两组集合后报试验。对试验结果进行定量评估表明:IAP PSSCA对降水异常具有一定的预测能力,特别是在中国东部受东亚季风及海温异常影响的地区,IAP PSSCA具有较高的预报技巧,其中以东南区域(包括江淮流域和华南地区)最高,尤其是对有洪涝灾害的降水异常年,距平相关系数在0.50左右,接近可供业务使用的要求,说明模式能够抓住在东亚季风区存在的某种物理机制,从而提高了这一地区的预报技巧;另外,两个大气环流模式相比,改进了地表反照率的AGCM 1.2的15年集合平均预测技巧略高于AGCM 1.1,特别是在华北地区,预测效果有明显提高,这表明改进地表反照率从而改进了模式的气候平均态的模拟,能提高气候模式的预测能力,说明较好的陆面过程引入模式对短期气候预测是有益的。  相似文献   

8.
通过采用一种较好地考虑了海气通量交换对下垫面特征非线性依赖的通量计算方案,利用较成熟的逐日通量距平耦合方案实现了次网格尺度海冰非均匀条件下一个全球大气环流模式和一个全球海洋环流模式在高纬地区的耦合,并完成了一个50年的长期积分。模拟结果表明,通量计算方案中水道的作用是合理的,耦合模式能较好地模拟出北半球高纬海冰的主要地理分布特征,但夏季北冰洋内部靠近欧亚大陆部分边缘海区海冰密集度偏大。  相似文献   

9.
平流层大气环流异常信号被认为对冬季对流层短期气候预测或中长期天气预报具有先兆性指示意义,但到目前为止,仍未真正用于短期气候预测。为了获取更多运用平流层环流异常信号预测对流层及地面短期气候的经验,该文利用北半球环状模 (NAM) 信号对2011—2012年冬季我国北方短期气候进行4次预测,并将预测结果与实况进行对比。在4次短期气候预测中,第2次和第3次预测结果与实况吻合很好:第2次成功预测了1月中旬到2月中旬我国东北和华北地区偏冷,第3次则成功预测了这种偏冷状态的持续。成功的主要原因是2011年12月—2012年2月平流层信号周期确定,且对流层和平流层之间动力耦合关系已经建立完全,平流层异常信号在该时段对流层和地面短期气候具有较强指示意义。  相似文献   

10.
我国短期气候预测的业务技术发展   总被引:6,自引:0,他引:6  
赵振国  刘海波 《浙江气象》2003,24(3):1-6,46
首先概述了我国短期气候预测技术和业务现代化发展的历史。近40多年来,我国短期气候预测业务技术经历了经验统计分析、数理统计分析、物理统计分析、动力与统计相结合4个主要发展阶段。其次分析了“九五”以来我国短期气候预测技术的新进展,通过“九五”攻关研究,增强了我国短期气候预测的物理基础、综合决策和业务预测能力,初步实现了动力与统计相结合,提高了自动化、客观化、可视化水平。最后探讨了未来我国短期气候预测技术发展的几个主要问题,一方面要大力发展动力气候模式,另一方面要不断改进提高物理统计方法,在汛期降水物理统计预测方法的研究中,应重点加强主导因素、中纬度环流异常、海洋与大气相互作用、年代际气候背景与年际气候异关系的研究。  相似文献   

11.
Studies on the seasonal to extraseasonal climate prediction at the Institute of Atmospheric Physics (IAP) in recent years were reviewed. The first short-term climate prediction experiment was carried out based on the atmospheric general circulation model (AGCM) coupled to a tropical Pacific oceanic general circulation model (OGCM). In 1997, an ENSO prediction system including an oceanic initialization scheme was set up. At the same time, researches on the SST-induced climate predictability over East Asia were made. Based on the biennial signal in the interannual climate variability, an effective method was proposed for correcting the model predicted results recently. In order to consider the impacts of the initial soil mois ture anomalies, an empirical scheme was designed to compute the soil moisture by use of the atmospheric quantities like temperature, precipitation, and so on. Sets of prediction experiments were carried out to study the impacts of SST and the initial atmospheric conditions on the flood occurring over China in 1998.  相似文献   

12.
针对未来1~10 a气候状态的近期气候预测(年代际预测)是当前国际气候领域的研究热点。本文综述了中国科学院大气物理研究所发展的基于耦合气候系统模式的年代际气候预测系统IAP-DecPreS相关的研究进展。IAP-DecPreS系统的核心部分是耦合模式海洋分量初始化方案,“集合最优插值-分析增量更新”(EnOI-IAU)方案,该方案将集合最优插值(EnOI)和增量分析更新(IAU)结合起来,能够同化原始的海洋次表层温度廓线观测资料,对耦合模式进行初始化。系统的年代际回报试验表明,IAP-DecPreS对太平洋年代际振荡和大西洋多年代际变率的预测技巧与耦合模式比较计划第五阶段(CMIP5)技巧较高的模式相当。IAP-DecPreS系统被广泛应用于气候预测相关研究,包括火山气溶胶对年代际预测技巧的影响,全场同化和异常场同化两种不同的初始化方法对ENSO、印度洋偶极子模态和印度洋洋盆模态等的预测技巧的影响。最后,结合国际发展态势,对未来IAP-DecPreS的发展进行了讨论。  相似文献   

13.
欧亚大陆积雪对我国春季气候可预报性的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
陈红 《大气科学》2017,41(4):727-738
利用大气环流模式IAP9L_CoLM,通过两组集合后报试验,考察了欧亚大陆积雪对我国春季气候可预报性的影响。一组试验为常规后报试验,积雪是由模式陆面过程预报得到的,另一组试验为积雪试验,模式积分过程中欧亚大陆雪水当量由微波遥感积雪资料替代,一天替换一次。通过分析两组试验后报结果的差异,来考察欧亚大陆积雪对我国春季(3~5月)气候可预报性的影响。分析表明:欧亚大陆积雪模拟水平的改善能提高春季欧亚大陆中高纬环流场(海平面气压场和中、高层位势高度场)的可预报性,模式对我国春季气温异常的年际变化和空间分布的可预报能力也有显著增强。对我国春季降水,虽然预报技巧较低,但引入较真实的欧亚积雪作用后,由于中高纬环流场预报技巧的改进导致降水的预测能力也有所改进。个例分析也表明,欧亚中高纬春季积雪异常模拟水平的改善导致了欧亚中高纬贝加尔湖及以南区域环流场可预报性的提高,最终使中国东部区域春季气候异常模拟技巧得以改善。以上结果也证实,欧亚大陆积雪是影响东亚区域春季气候的一个重要因子,要提高模式对中国春季气候的预报技巧,积雪模拟水平的改进是非常必要的。  相似文献   

14.
利用全球海洋—大气快速耦合模式(Fast Ocean-Atmosphere Model,FOAM),采用模式中的初值方法,研究了湾流区海温再现过程及其对北半球大气环流和气候的影响。FOAM模式很好地模拟了北大西洋湾流区的海温"再现"过程,模式中海面热通量异常与SST异常表现出不同步的响应特征。海面热通量异常在初冬季节达到最大值,而SST异常滞后,在冬季晚期达到最大值,从而在初冬和晚冬对北半球大气环流造成不同的影响。初冬季节北半球大气环流主要受海洋热通量异常的强迫,在北大西洋和北太平洋上空呈现相当正压的异常低压槽响应,北极地区为异常高压脊,类似北极涛动的负位相,可能造成欧洲南部和北非大陆气温偏高,亚洲大陆气温偏低。而晚冬季节北半球大气环流主要受SST异常的驱动,在北大西洋和北太平洋上空表现为相当正压的异常高压脊响应,北极地区为异常低压槽,类似北极涛动的正位相,可能造成欧洲南部和北非大陆气温偏低,亚洲大陆气温偏高,中国东部降水异常偏多30%左右。北太平洋大气环流的异常由北大西洋湾流区海洋热通量和SST异常强迫下游大气环流所激发,进一步通过Rossby驻波的能量频散东传至北太平洋而造成的。  相似文献   

15.
辐射参数化方案对气候模拟和回报的影响   总被引:1,自引:1,他引:0       下载免费PDF全文
研究两种不同辐射参数化方案(Morcrette 方案和Ritter方案)对一个大气环流模式及其与一个海洋环流模式的耦合模式的模拟和回报效果的影响. 大气模式的模拟结果表明,采用Morcrette方案模拟的降水较采用Ritter方案有明显改进.采用Morcrette辐射方案的大气模式对夏季500 hPa高度场的模拟比采用Ritter方案的大气模式有明显改进,但对冬季500 hPa高度场的模拟没有改进.大气-海洋耦合模式的20年夏季回报结果表明采用Morcrette方案回报的夏季降水在华北和江淮地区明显比采用Ritter辐射方案好;对于夏季温度,带有Morcrette方案的耦合模式的回报在江淮地区没有带有Ritter方案的耦合模式好,但在黄河以北和新疆等地区,前者明显好于后者.  相似文献   

16.
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   

17.
Freshening of high latitude surface waters can change the large-scale oceanic transport of heat and salt. Consequently, atmospheric and sea ice perturbations over the deep water production sites excite a large-scale response establishing an oceanic "teleconnection" with time scales of years to centuries. To study these feedbacks, a coupled atmosphere-ocean-sea ice model consisting of a two dimensional atmospheric energy and moisture balance model (EMBM) coupled to a thermodynamic sea ice model and an ocean general circulation model is utilised. The coupled model reproduces many aspects of the present oceanic circulation. We also investigate the climate impact of changes in fresh water balance during an ice age initiation. In this experiment part of the precipitation over continents is stored within continental ice sheets. During the buildup of ice sheets the oceanic stratification in the North Atlantic is weakened by a reduced continental run-off leading to an enhanced thermohaline circulation. Under these conditions salinity is redistributed such that deep water is more saline than under present conditions. Once the ice sheets built up, we simulate an ice age climate without net fresh water storage on the continents. In this case the coupled model reproduces the shallow and weak overturning cell, an ice edge advance insulating the upper ocean, and many other aspects of the glacial circulation.  相似文献   

18.
China is a monsoon country.The most rainfalls in China concentrate on the summer seasons.More frequent floods or droughts occur in some parts of China.Therefore,the prediction of summer rainfall in China is a significant issue.As we know,the obvious impacts of the sea surface temperature anomalies(SSTA)on the summer rainfall over China have been noticed.The predictions of the SSTA have been involved in the research.The key project on short-term climate modeling prediction system has been finished in 2000.The system included an atmospheric general circulation model named AGCM95,a coupled atmospheric-oceanic general circulation model named AOGCM95,a regional climate model over China named RegCM95,a high-resolution Indian-Pacific OGCM named IPOGCM95,and a simplified atmosphere-ocean dynamic model system named SAOMS95.They became the operational prediction models of National Climate Center(NCC).Extra-seasonal predictions in 2001 have been conducted by several climate models,which were the AGCM95,AOGCM95,RegCM95,IPOGCM95,AIPOGCM95,OSU/NCC,SAOMS95,IAP APOGCM and CAMS/ZS.All of those models predicted the summer precipitation over China and/or the annual SSTA over the tropical Pacific Ocean in the Modeling Prediction Workshop held in March 2001.The assessments have shown that the most models predicted the distributions of main rain belt over Huanan and parts of Jiangnan and droughts over Huabei-Hetao and Huaihe River Valley reasonably.The most models predicted successfully that a weaker cold phase of the SSTA over the central and eastern tropical Pacific Ocean would continue in 2001.The evaluations of extra-seasonal predictions have also indicated that the models had a certain capability of predicting the SSTA over the tropical Pacific Ocean and the summer rainfall over China.The assessment also showed that multi-model ensemble(super ensembles)predictions provided the better forecasts for both SSTA and summer rainfall in 2001,compared with the single model.It is a preliminary assessment for the extra-seasonal predictions by the climate models.The further investigations will be carried out.The model system should be developed and improved.  相似文献   

19.
China is a monsoon country.The most rainfalls in China concentrate on the summer seasons.More frequent floods or droughts occur in some parts of China.Therefore,the prediction ofsummer rainfall in China is a significant issue.As we know,the obvious impacts of the sea surfacetemperature anomalies(SSTA)on the summer rainfall over China have been noticed.Thepredictions of the SSTA have been involved in the research.The key project on short-term climate modeling prediction system has been finished in 2000.The system included an atmospheric general circulation model named AGCM95,a coupledatmospheric-oceanic general circulation model named AOGCM95,a regional climate model overChina named RegCM95,a high-resolution Indian-Pacific OGCM named IPOGCM95,and asimplified atmosphere-ocean dynamic model system named SAOMS95.They became theoperational prediction models of National Climate Center(NCC).Extra-seasonal predictions in 2001 have been conducted by several climate models,which werethe AGCM95,AOGCM95,RegCM95,IPOGCM95,AIPOGCM95,OSU/NCC,SAOMS95,IAPAPOGCM and CAMS/ZS.All of those models predicted the summer precipitation over China and/or the annual SSTA over the tropical Pacific Ocean in the Modeling Prediction Workshop held inMarch 2001.The assessments have shown that the most models predicted the distributions of main rain beltover Huanan and parts of Jiangnan and droughts over Huabei-Hetao and Huaihe River Valleyreasonably.The most models predicted successfully that a weaker cold phase of the SSTA over thecentral and eastern tropical Pacific Ocean would continue in 2001.The evaluations of extra-seasonal predictions have also indicated that the models had a certaincapability of predicting the SSTA over the tropical Pacific Ocean and the summer rainfall overChina.The assessment also showed that multi-model ensemble(super ensembles)predictionsprovided the better forecasts for both SSTA and summer rainfall in 2001,compared with the singlemodel.It is a preliminary assessment for the extra-seasonal predictions by the climate models.Thefurther investigations will be carried out.The model system should be developed and improved.  相似文献   

20.
We describe a coupled climate model of intermediate complexity designed for use in global warming experiments. The atmospheric component is a two-dimensional (zonally averaged) statistical-dynamical model based on the Goddard Institute for Space Study's atmospheric general circulation model (GCM). In contrast with energy-balance models used in some climate models of intermediate complexity, this model includes full representation of the hydrological and momentum cycles. It also has parameterizations of the main physical processes, including a sophisticated radiation code. The ocean component is a coarse resolution ocean GCM with simplified global geometry based on the Geophysical Fluid Dynamics Laboratory modular ocean model. Because of the simplified geometry the resolution in the western boundary layers can be readily increased compared to conventional coarse resolution models, without increasing the model's computational requirements in a significant way. The ocean model's efficiency is also greatly increased by using a moderate degree of asynchronous coupling between the oceanic momentum and tracer fields. We demonstrate that this still allows an accurate simulation of transient behavior, including the seasonal cycle. A 100 years simulation with the model requires less than 8 hours on a state-of the art workstation. The main novelty of the model is therefore a combination of computational efficiency, statistical-dynamical atmosphere and 3D ocean. Long-term present-day climate simulations are carried out using the coupled model with and without flux adjustments, and with either the Gent-McWilliams (GM) parametrization scheme or horizontal diffusion (HD) in the ocean. Deep ocean temperatures systematically decrease in the runs without flux adjustment. We demonstrate that the mismatch between heat transports in the uncoupled states of two models is the main cause for the systematic drift. In addition, changes in the circulation and sea-ice formation also contribute to the drift. Flux adjustments in the freshwater fluxes are shown to have a stabilizing effect on the thermohaline circulation in the model, whereas the adjustments in the heat fluxes tend to weaken the global "conveyor". To evaluate the model's response to transient external forcing global warming simulations are also carried out with the flux-adjusted version of the coupled model. The coupled model reproduces reasonably well the behavior of more sophisticated coupled GCMs for both current climate and for the global warming scenarios.  相似文献   

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