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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
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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
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区域海气耦合模式是研究局地海气相互作用过程影响气候变率的重要平台,也是对全球气候模式进行"动力降尺度"的重要工具.本文介绍了LASG(State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics)/IAP(Institute of Atmospheric Physics)发展的区域海气耦合模式FROALS(Flexible Regional Ocean-Atmosphere-Land System model),并总结了过去五年围绕该区域海气耦合模式开展的研究工 作.FROALS的特点之一是有两个完全不同的大气模式分量和海洋模式分量选项,可以适应不同的模拟研究需 求.针对区域海气耦合模式在西北太平洋地区的模拟偏差,通过分步骤考察不同大气模式分量和不同海洋模式分量对模式模拟性能的影响,指出大气模式是导致区域海气耦合偏差的主要分量.通过改进对流触发的相对湿度阈值标准,有效地改善了此前区域海气耦合模式在亚洲季风区普遍出现的"模拟海温冷偏差".改进的FROALS对西北太平洋地区的大气和海洋环境有较好的模拟能力,合理地再现了西北太平洋地区表层洋流气候态和年际变率.较之非耦合模式,考虑区域海气耦合过程后,改进了东亚和南亚地区的降水和热带气旋潜势年际变率的模拟.最后,针对东亚—西北太平洋地区,利用FROALS对IAP/LASG全球气候模式模拟和预估的结果进行了动力降尺 度,得到了东亚区域50 km高分辨率区域气候变化信息.分析显示,FROALS模拟得到的东亚区域气候较之全球气候模式和非耦合区域气候模式结果具有明显的"增值",显示出区域海气耦合模式在该区域良好的应用前景. 相似文献
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区域气候模式研究进展 总被引:5,自引:2,他引:5
全面回顾了区域气候模式的分类、发展和最新研究动态,指出区域气候模式研究有了长足的发展,其中重要的有:加入雪盖、土壤水等作用的陆面过程,全球模式与区域细网格模式的嵌套由一维发展到三维,由一层发展到多层,发展了更加合理的参数化方案;但也存在许多不足,模式提供的植被资料与实情相差很大,对于沙漠地区的植被盖度的算法不尽合理,对次网格地形及对其湍流通量输送过程的刻画不够细致等。因此,建议利用遥感手段采用非线性方法(如分形等)对遥感资料施行反演,进行多尺度的双向模式嵌套。 相似文献
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Argo大洋观测资料的同化及其在短期气候预测和海洋分析中的应用 总被引:3,自引:0,他引:3
国际Argo(Array for Real-time Geostrophic Oceanography)计划的实施,提供了前所未有的全球深海大洋0~2000 m水深范围内的海水温度和盐度观测资料,在大气和海洋科研业务中应用这一全新的资料,是深入认识大气和海洋变异、提高我国气候预测、海洋监测分析和预报能力的一个关键所在.通过开发非线性温—盐协调同化方案和利用同化高度计资料来调整模式的温度和盐度场,建立了可同化包括Argo等多种海洋观测资料的全球海洋资料变分同化系统,提高了对全球海洋的监测分析能力.实现了海洋资料同化系统与全球海气耦合模式的耦合,显著提高了短期气候预测水平.利用Argo资料改进了海洋动力模式中的物理过程参数化方案,有效提高了海洋模式对真实大洋的模拟能力和对厄尔尼诺/拉尼娜的预测能力.开发了利用Argo浮标漂流轨迹推算全球海洋表层和中层流的方法,提高了推算的全球表层流、中层流资料质量,有效弥补了洋流观测的匮乏. 相似文献
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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
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基于耦合器框架,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大气环流谱模式 (SAMIL)最近成功地实现了与海洋、海冰等气候分量模式的耦合,形成了“非通量调整”的海-陆-气-冰直接耦合的气候模式系统(FGOALS-s)。在耦合系统中,由于海温、海冰等的分布由预报模式驱动,大气与海洋、海冰之间引入了相互作用过程,这样大气环流的模拟特征与耦合前会有不同。为分析耦合系统的性能,作者对耦合前后的模拟结果进行了分析比较,重点是大气模拟特征的差异。结果表明,耦合前、后大气环流的基本特征相似,都能成功地模拟出主要的环流系统分布及季节变化,但是由于海温和海冰的模拟存在系统性的偏差,使得耦合后的大气环流受到明显影响。例如耦合后热带海温偏冷,南大洋、北太平洋和北大西洋等中纬度地区的海温偏高,导致海温等值线向高纬海域的伸展较弱,海温经向梯度减小。耦合后海冰在北极区域范围偏大,在南极周边地区则偏小。海温、海冰分布模拟的偏差影响到中、高纬低层大气的温度。热带海温偏低,使得赤道地区降水偏弱,凝结潜热减少,热带对流层中高层温度比耦合前要低,大气温度的经向梯度减小。经向温度梯度的改变,直接影响到对平均经圈环流及西风急流强度的模拟。尽管耦合系统中海温、海冰的模拟存在偏差,但在亚洲季风区,耦合后季风环流及降水等的分布都比耦合前单独大气模式的结果合理,表明通过海[CD*2]气相互作用可减少耦合前季风区的模拟误差,改善季风模拟效果。比较发现,海温、海冰模拟的偏差,除与海洋模式中经向热输送偏弱、海冰模式中海冰处理等有关外,也与大气模式中总云量模拟偏低有关。大气模式本身的误差,特别是云、辐射过程带来的误差,对耦合结果具有极为重要的影响。完全耦合后,这些误差通过与海洋、海冰的反馈作用而放大。因此,对于FGOALS-s而言,要提高耦合系统的整体性能,除改进各气候分量模式的模拟性能外,需要重点改进大气模式中的云、辐射过程。 相似文献
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J. Egger 《Climate Dynamics》1997,13(4):285-292
Flux correction schemes are used in order to suppress the drift of coupled ocean atmosphere models. This technique is tested
for a simple box model of the climate system. Two “perfect” models of the ocean and the atmosphere are available. These are
coupled to form an ocean-atmosphere model representing the true climate system. This climate system is simulated by a climate
model which is also constructed by coupling those two perfect models. This time, however, both models are run first separately
as models of the atmosphere and the ocean. In that case, “observations” from the climate system are prescribed at the ocean
surface in the uncoupled models. It is assumed that these observations are imperfect. A drift results, when these models are
coupled to form an ocean-atmosphere stimulation model. A flux adjustment scheme is implemented to remove this drift. It is
argued that the merits and shortcomings of the flux correction technique can be assessed more clearly this way than by coupling
imperfect models as is done normally. Sensitivity tests are performed where either radiation parameters are changed or a salt
anomaly is implanted. Model parameters are chosen such that the ocean has a thermally direct circulation in the unperturbed
climate state. It is found that the flux correction technique is performing satisfactorily as long as the imposed perturbations
are small enough so that the ocean circulation does not change its sense. If, however, the model climate is close to the transition
to an indirect circulation, then the flux correction technique is unreliable. The predictions of the coupled model with flux
correction may deviate substantially from the response of the climate system in that case.
Received: 4 December 1995/Accepted: 15 October 1996 相似文献
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中国地球气候系统模式研究进展:CMIP计划实施近20年回顾 总被引:1,自引:0,他引:1
在系统总结过去20年从CMIP1到CMIP4世界各国模式的综合情况基础上,回顾了中国气候模式参与CMIP科学试验的概况。在此基础上,慨述了CMIP5的试验设计,总结了参加CMIP5的5个中国气候模式的特点。随后,从高分辨率模式研发、地球系统模式研发、地球气候系统模式最为关键的分量——大气环流模式和海洋环流模式研发的角度,提出了中国地球气候系统模式发展面临的挑战,指出了中国模式发展面临的机遇。针对如何从国家层次协调以实现地球气候模式的可持续发展问题,给出了美国国家科学院最近发布的《推动气候模拟的国家战略》所提出的九条措施作为参考。 相似文献
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C. J. C. Reason 《Meteorology and Atmospheric Physics》1996,61(1-2):1-18
Summary Parameterisations of mixing induced through shear instability, internal wave breaking, and double diffusion are investigated in simulations of ocean climate using a global ocean general circulation model (OGCM). Focus is placed on the sensitivity of the large scale circulation, water mass formation and transport of heat as measures of the model's ability to represent current climate. The model resolution is typical of OGCMs being coupled to atmospheric. GCMs in climate models and the parameterisations investigated are all computationally inexpensive enough to allow for integrations on long time scales. Under the assumption of constant vertical eddy coefficients (the control case), the model climatology displays acceptable values of North Atlantic Deep Water formation, Antarctic Circumpolar Current (ACC) transport, and Indonesian through-flow but an excessively deep and diffuse pycnocline structure with weak stratification in the deep ocean. It is found that various circulation and water mass properties are sensitive to the choice of parameterisation of vertical mixing and that determining a scheme which works satisfactorily over all regions (tropical, mid-latitude, and polar) of the domain is not straightforward. Parameterisations of internal wave breaking or upper ocean shear instability lead to some improvements in the model water mass formation. ACC and poleward heat transport when compared to the control case whereas parameterisations of double diffusive processes did not. Based on these and other results, various recommendations are made for mixing parameterisations in ocean climate models.With 8 Figures 相似文献
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Review of simulations of climate variability and change with the GFDL R30 coupled climate model 总被引:5,自引:0,他引:5
T. Delworth R. Stouffer K. Dixon M. Spelman T. Knutson A. Broccoli P. Kushner R. Wetherald 《Climate Dynamics》2002,19(7):555-574
A review is presented of the development and simulation characteristics of the most recent version of a global coupled model for climate variability and change studies at the Geophysical Fluid Dynamics Laboratory, as well as a review of the climate change experiments performed with the model. The atmospheric portion of the coupled model uses a spectral technique with rhomboidal 30 truncation, which corresponds to a transform grid with a resolution of approximately 3.75° longitude by 2.25° latitude. The ocean component has a resolution of approximately 1.875° longitude by 2.25° latitude. Relatively simple formulations of river routing, sea ice, and land surface processes are included. Two primary versions of the coupled model are described, differing in their initialization techniques and in the specification of sub-grid scale oceanic mixing of heat and salt. For each model a stable control integration of near millennial scale duration has been conducted, and the characteristics of both the time-mean and variability are described and compared to observations. A review is presented of a suite of climate change experiments conducted with these models using both idealized and realistic estimates of time-varying radiative forcing. Some experiments include estimates of forcing from past changes in volcanic aerosols and solar irradiance. The experiments performed are described, and some of the central findings are highlighted. In particular, the observed increase in global mean surface temperature is largely contained within the spread of simulated global mean temperatures from an ensemble of experiments using observationally-derived estimates of the changes in radiative forcing from increasing greenhouse gases and sulfate aerosols. 相似文献
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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
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Global Coupled Ocean-Atmosphere General Circulation Models in LASG/IAP 总被引:28,自引:11,他引:17
Coupled ocean-atmospheric general circulation models are the only tools to quantitatively simulate the climate system. Since the end of the 1980s, a group of scientists in the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS), have been working to develop a global OGCM and a global coupled ocean-atmosphere general circulation model (CGCM). From the original flux anomalycoupling model developed in the beginning of the 1990s to the latest directly-coupling model, LASG scientists have developed four global coupled GCMs. This study summarizes the development history of these models and describes the third and fourth coupled GCMs and selected applications. Strengths and weaknesses of these models are highlighted. 相似文献