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1.
Numerical Experiments on the Spin-up Time for Seasonal-Scale Regional Climate Modeling 总被引：1，自引：0，他引：1 
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下载免费PDF全文 In this paper,the numerical experiments on the issue of spin-up time for seasonal-scale regional climate modeling were conducted with the newly Regional Climate Model (RegCM3),in the case of the abnormal climate event during the summer of 1998 in China.To test the effect of spin-up time on the regional climate simulation results for such abnormal climate event,a total of 11 experiments were performed with different spin-up time from 10 days to 6 months,respectively.The simulation results show that,for the meteorological variables in the atmosphere,the model would be running in"climate mode"after 4-8-day spin-up time,then, it is independent of the spin-up time basically,and the simulation errors are mainly caused by the model's failure in describing the atmospheric processes over the model domain.This verifies again that the regional climate modeling is indeed a lateral boundary condition problem as demonstrated by earlier research work. The simulated mean precipitation rate over each subregion is not sensitive to the spin-up time,but the precipitation scenario is somewhat different for the experiment with different spin-up time,which shows that there exists the uncertainty in the simulation to precipitation scenario,and such a uncertainty exhibits more over the areas where heavy rainfall happened.Generally,for monthly-scale precipitation simulation,a spin-up time of 1 month is enough,whereas a spin-up time of 2 months is better for seasonal-scale one. Furthermore,the relationship between the precipitation simulation error and the advancement/withdrawal of East Asian summer monsoon was analyzed.It is found that the variability of correlation coefficient for precipitation is more significant over the areas where the summer monsoon is predominant.Therefore,the model's capability in reproducing precipitation features is related to the heavy rainfall processes associated with the advancement/withdrawal of East Asian summer monsoon,which suggests that it is necessary to develop a more reliable parameterization scheme to capture the convective precipitation of heavy rainfall pro- cesses associated with the activities of East Asian summer monsoon,so as to improve the climate modeling over China. 相似文献
2.
我国近年来短期气候预测研究的若干进展 总被引：9，自引：4，他引：5
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
3.
于革 《气候变化研究进展》2007,3(1):20-025
白垩纪是地质史上一个典型的温室气候时期，国际上围绕白垩纪气候成因开展了一系列模拟研究。在评述白垩纪古气候模拟的基础上，讨论了气候模式的应用和发展、古气候边界场设置和模拟试验，分析白垩纪温室气体、古地理、古海洋以及海陆生态系统对气候的作用和反馈。这些古气候模拟试验锁定在气候变化的关键时段和驱动因子、测试地球内外动力和地球各圈层反馈作用，可为认识温室气候的成因、探讨气候变化内在机制和预测未来气候提供重要的科学依据。 相似文献
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5.
A policy network analysis using a questionnaire survey was conducted to identify the main climate policy actors in South Korea and examine how they form alliances and come into conflict over four major issues. Generally, it was found that governmental organizations are the main actors in the South Korean climate policy arena and that they mediate between the business and civil sectors. In particular, key organizations in each sector play a leading role in the formation and maintenance of at least two distinct alliance networks: growth and environmental. In particular, the growth network has been stronger and more intense than the environmental network, with the exception of nuclear power policy. The crucial drivers of proactive policy discourse in South Korea have been scientific discourse and a consensus on the advent of anthropogenic climate change by the international scientific community, the international climate change negotiations and the pressure to commit to GHG emissions reduction, and low-carbon green growth strategy.Policy relevanceThe positions of South Korean governmental organizations (as well as other civil society organizations) on the four major issues of climate policy have not been aligned. The government has not acted as a unified body; instead it is an aggregated body composed of organizations with competing interests. If policy actors with different interests share the recognition of the state of the country within global society and understand international pressure as well as the urgency of combating climate change, then a common policy goal can be achieved. It is essential for the government to exert proactive leadership for climate policies in mediating the growth and environmental networks. It is important to boost environmental networks in order to overcome the alliance of growth networks. A more proactive response for combating climate change would establish open policy-making processes for environmental network actors and provide economic opportunities for climate actions. 相似文献
6.
从气候监测诊断、气候预测、气候系统模式、气候评价与灾害风险管理、气候变化业务和气候业务平台等角度,系统概述了我国现代气候业务现状。提出了以气候监测和动力学诊断为基础,以提升气候服务、气候风险管理和应对气候变化能力为目标,以发展客观化气候预测技术和定量化气候评估方法为核心的现代气候业务概念。分析了国际气候业务发展趋势及我国气候业务的差距,明确了加强气候系统基本变量监测、提高气候系统模式分辨率和改进物理过程、发展第2代短期气候预测系统、研发气象灾害风险评估方法并建立中国气候服务系统 (CFCS) 等发展任务。 相似文献
7.
An Assessment on the Performance of IPCC AR4 Climate Models in Simulating Interdecadal Variations of the East Asian Summer Monsoon 总被引：3，自引：0，他引：3 下载免费PDF全文
下载免费PDF全文 Observations from several data centers together with a categorization method are used to evaluate the IPCC AR4 （Intergovernmental Panel on Climate Change, the Fourth Assessment Report） climate models＇ performance in simulating the interdecadal variations of summer precipitation and monsoon circulation in East Asia. Out of 19 models under examination, 9 models can relatively well reproduce the 1979-1999 mean June-July-August （JJA） precipitation in East Asia, but only 3 models （Category-1 models） can capture the interdecadal variation of precipitation in East Asia. These 3 models are： GFDL-CM2.0, MIROC3.2 （hires）, and MIROC3.2 （medres）, among which the GFDL-CM2.0 gives the best performance. The reason for the poor performance of most models in simulating the East Asian summer monsoon interdecadal variation lies in that the key dynamic and thermal-dynamic mechanisms behind the East Asian monsoon change are missed by the models, e.g., the large-scale tropospheric cooling and drying over East Asia. In contrast, the Category-1 models relatively well reproduce the variations in vertical velocity and water vapor over East Asia and thus show a better agreement with observations in simulating the pattern of ＂wet south and dry north＂ in China in the past 20 years.
It is assessed that a single model＇s performance in simulating a particular variable has great impacts on the ensemble results. More realistic outputs can be obtained when the multi-model ensemble is carried out using a suite of well-performing models for a specific variable, rather than using all available models. This indicates that although a multi-model ensemble is in general better than a single model, the best ensemble mean cannot be achieved without looking into each member model＇s performance. 相似文献
It is assessed that a single model＇s performance in simulating a particular variable has great impacts on the ensemble results. More realistic outputs can be obtained when the multi-model ensemble is carried out using a suite of well-performing models for a specific variable, rather than using all available models. This indicates that although a multi-model ensemble is in general better than a single model, the best ensemble mean cannot be achieved without looking into each member model＇s performance. 相似文献
8.
平均气候与极端气候两者发生的概率具有密切联系.从理论和观测事实两方面证明一地平均气候与其极端气候的对应概率存在着明显的非线性关系.假定气候变量有对称概率分布和非对称概率分布两种状况,从理论上证明,平均气候变化前后所对应的极端气候概率具有非线性变化;通过对若干个代表站及气候场资料的平均值与所对应极值概率计算结果,证明理论符合观测事实.进一步借助于数值试验考察了概率分布模式的各个参数之变化对极端气候概率的影响.根据观测事实的举例,也表明了不同概率分布条件下,基本上都有如此变化规律. 相似文献
9.
Progress in the Development and Application of Climate Ocean Models and Ocean-Atmosphere Coupled Models in China 总被引：2，自引：3，他引：2
ZHOU Tianjun YU Yongqiang LIU Hailong LI Wei YOU Xiaobao ZHOU Guangqing 《大气科学进展》2007,24(6):1109-1120
A review is presented about the development and application of climate ocean models and oceanatmosphere coupled models developed in China as well as a review of climate variability and climate change studies performed with these models. While the history of model development is briefly reviewed, emphasis has been put on the achievements made in the last five years. Advances in model development are described along with a summary on scientific issues addressed by using these models. The focus of the review is the climate ocean models and the associated coupled models, including both global and regional models, developed at the Institute of Atmospheric Physics, Chinese Academy of Sciences. The progress of either coupled model development made by other institutions or climate modeling using internationally developed models also is reviewed. 相似文献
10.
林而达 许吟隆 蒋金荷 李玉娥 杨修 张建云 李从先 吴绍洪 赵宗群 吴建国 居辉 严昌荣 王守荣 刘允芬 杜碧兰 赵成义 秦保芳 刘春蓁 黄朝迎 张小全 马世铭 《气候变化研究进展》2006,2(2):51-56
已经观测到的气候变化影响是显著的、多方面的。各个领域和地区都存在有利和不利影响,但以不利影响为主,未来的气候变暖将会对中国的生态系统、农业以及水资源等部门和沿海地区产生重大的不利影响。采取适应措施可以减轻气候变化的不利影响,应将适应气候变化的行动逐步纳入国民经济和社会发展的中长期规划中。由于我国科学研究的相对不足和科学认识能力的局限,目前的气候变化影响评估方法和结果还存在很大的不确定性。应当加强区域适应气候变化的案例研究、扩大研究领域、加强极端天气、气候事件影响的研究,以降低影响评估的不确定性,并提出切实可行的适应对策。 相似文献
11.
区域气候自忆预测模式的计算方案及其结果 总被引：3，自引：0，他引：3
区域气候预测的自忆模式是由描写温度、降水变化的差分-积分方程构成的。文中推导了用EOF展开的预测方程组,给出了该方程组的数值计算方案和递推格式。运用我国1951~1992年的月温度、降水场和区域500 hPa高度场格点资料,对6~8月汛期预测作了回报试验,结果表明该模式的预测能力是很高的。 相似文献
12.
依据政府间气候变化专门委员会 (IPCC) 第5次评估报告以及国内相关科学研究成果,使用最新的观测资料凝练了对全球气候变化的有关认识;从极端天气气候事件和气候承载力角度,分析了气候变化给我国带来的气候风险。研究发现:1961—2015年我国平均高温日数增加了28.4%,暴雨日数增加了8.2%。21世纪以来,登陆我国热带气旋的强度明显增加。在全球气候变暖的背景下,我国气候承载力将发生明显变化,未来面临的气候风险将加大。因此,保障我国气候安全,需要科学认识气候,提高气候风险意识; 主动适应气候,提高应对极端事件能力;努力保护气候,减缓气候变化的影响。 相似文献
13.
This paper presents a quantitative analysis of international representation in the activities of the Intergovernmental Panel on Climate Change using expert authorship counts by country in each of the four IPCC assessment reports (1990, 1995, 2001 and 2007). Overall, we find that 45% of countries, all Non-Annex 1, have never had authors participate in the IPCC process; on the other hand, European and North American experts are make up more than 75% of all authors (N = 4394). Generalized linear models using negative binomial regression were used to quantitatively estimate the effect of a number of socio-economic, environmental and procedural factors influencing country-level participation in the IPCC. Per capita gross domestic product, population, English-speaking status, and levels of tertiary education were all found to be statistically significant drivers of authorship counts. In particular, participation by authors from English-speaking Non-Annex 1 countries is 2.5 times greater than those that are non-English speaking. Regionally small island nations of Oceania were the most severely under-represented group. South American and Asian countries had fewer authors, and African countries had more authors than what might be expected on the basis of demographic and socio-economic data. These differences across nations partly reflect existing scientific capacity that will be slow to change. However, the on-going under-representation of developing country scientists in the IPCC, particularly in the assessment of climate science (WGI) and climate mitigation (WGIII) warrants greater efforts to close the capacity gap. 相似文献
14.
使用20km高水平分辨率的区域气候模式RegCM3,单向嵌套FvGCM/CCM3全球模式,进行了中国区域气候变化的数值模拟试验,分析华北地区夏半年4-9月的气温、降水和高温、干旱事件的变化。模式积分时间分为两个时段,分别为当代的1961-1990年和在IPCC SRES A2温室气体排放情景下的21世纪末2071-2100年。模式检验结果表明:在大部分月份,区域模式对当代气候的模拟都较全球模式更好。两个模式模拟的未来气温和降水变化,在空间分布型和量级上都有一定不同,如区域模式的升温更高,降水出现大范围减少等。此外,使用日最高气温不低于35℃的日数(D_(T35))和考虑了湿度因素的炎热指数(I_(H))不低于35℃的日数(D_(H135)),分析了区域模式模拟的未来高温事件变化,结果表明:未来华北地区D_(T35)和平原地区D_(H135)均有较大增加。未来华北地区的连续干旱日数(CDD)将增加,依照UNEP(United Nations Environment Programme)干旱指数(A_(U))给出的气候湿润区将有较大幅度减少,而半湿润半干旱区和半干旱区面积将增加。 相似文献
15.
气候预测中的集合方法初探 总被引：11，自引：2，他引：9
介绍了气候预测中的集合方法。该文作者曾在1996年论证了在西太平洋暖池区海温异常与东亚夏季风的共同作用下存在一个可预测的气候异常区,部分地改变了气候不可预测的论断。如何从与大量不可预测结果混杂在一起的结果中提炼出可预测部分是集合方法的重要目的之一。文中也讨论了由于大气运动固有的动力学特性,其集合预测与经典的数学考虑有所区别,天气与气候预测有不同的特点,其集合方法、目的也应有所不同,由此对集合方法提出了一些新的建议。文中同时介绍了首次在气候预测中发现的多平衡态现象,建议了如何判定多平衡的出现,以及如何利用多平衡态来改善对不同区域的预测。 相似文献
16.
季节尺度区域气候模拟适应调整时间选取问题的数值试验 总被引：2，自引：0，他引：2
文中利用区域气候模式RegCM3,以1998年夏季中国异常气候事件为例,对季节尺度区域气候模拟适应调整时间的选取问题进行了数值研究。共做了11个试验,每个试验的适应调整时间最短为10 d,最长为6个月,以检验适应调整时间长短对夏季中国异常气候事件模拟结果的影响。结果表明:对于大气变量而言,模式通常在经过4—8 d的适应调整时间后,就进入"气候模态"运行,此后模拟误差主要是由于模式对区域内大气过程描述能力不足造成的,对适应调整时间选取不再敏感,这进一步证实了区域气候模拟是一个边值问题的观点。各气候区平均降水量模拟结果受适应调整时间影响也不大,但不同的适应调整时间对降水分布格局模拟将产生一定影响,降水分布模拟结果随适应调整时间的不同存在一定的不确定性,这种不确定性通常出现在强降水发生区域。总之,对于季节尺度降水模拟,适应调整时间大于2个月效果更好。对降水分布格局模拟误差和东亚夏季风系统进退过程之间关系的进一步分析发现,模式对受夏季风系统影响比较大的区域模拟的降水相关系数变化性也比较大,因此,发展合适的积云对流参数化方案以提高受夏季风系统直接影响区域强降水过程的描述能力是改进区域气候模式对中国区域夏季气候模拟效果的有效途径。 相似文献
17.
年代际气候变化的研究进展 总被引：3，自引：0，他引：3
年代际气候变化是月、季、年际气候变化及预测的背景。20世纪90年代以来，年代际气候变化的研究引起了国内外学者的极大关注，开展了大量富有成效的研究工作。本文从大气环流、中国气温和降水、海洋以及海气系统等4个方面对年代际气候变化的研究进展进行了总结，提出了年代际气候变化，尤其是东亚地区的年代际气候变化研究需要进一步解决的科学问题。 相似文献
18.
典型低碳宜居社区人居气候舒适性评价 总被引：1，自引：0，他引：1
利用武汉观象台近32年气象资料及区域加密站近5年资料,计算了近10年武汉市入四季日及四季长度,并与近30年四季变化特征进行了比较。采用以温湿指数、风效指数及体感温度指数为基础的人居环境气候舒适度评价指标体系,对武汉市一个典型低碳宜居社区进行人居气候舒适性区划。结果表明：近10年来武汉市夏季延长,春秋冬季略微缩短,城市人居气候舒适日在减少;典型低碳宜居社区近10年平均人居气候舒适季129天,供冷季72天,除湿季74天,冷季34天,供暖季132天。社区人居气候舒适性评价结果可以为社区能源科学调度、合理利用自然气候资源提供依据。 相似文献
19.
经过近60年的发展,我国短期气候预测技术和方法也有了长足进步。近年来,一些新的预报技术和机理认识不断应用于短期气候预测业务。ARGO海洋观测资料的使用大大提高了业务模式的预测技巧,新一代气候预测模式系统已经投入准业务化运行,研发了多种模式降尺度释用技术,多模式气候预测产品解释应用集成系统(MODES)和动力-统计结合的季节预测系统(FODAS)逐渐应用于业务中,大气季节内振荡(MJO)逐步在延伸期预报中得到应用。近年来,对全球海洋、北极海冰、欧亚积雪、南半球环流系统对东亚季风影响的新认识也不断引入到短期气候预测业务中。这些新技术和新认识的应用极大提高了我国短期气候预测的业务能力。 相似文献
20.
降尺度方法在东亚气候预测中的应用 总被引：4，自引：2，他引：2
东亚气候变异十分复杂,全球动力预测系统对该地气候异常的预测能力偏低,如何进一步提高东亚地区气候异常的预测水平是一个非常重要的科学和现实需求问题。为此,近些年一系列的动力和统计降尺度方法得以发展。本文主要回顾了这些降尺度方法在东亚气候预测研究和实时预测中的应用。首先,文中简要介绍了我国目前应用于实时预测的全球动力预测系统及其性能,这是开展降尺度的科学和技术基础;在此基础上,从区域模式物理过程参数化方案的评估与遴选、区域模式在东亚气候预测中的应用两个方面,对于动力降尺度方法的发展和应用做了回顾;在统计降尺度的综述中,本文主要关注了东亚夏季汛期和冬季气候异常的预测,特别是针对东亚冬季气候异常,本文中提出了新的高效的统计与动力相结合的预测方法。最后,展望了短期气候预测需要进一步深入研究的科学和技术问题。 相似文献