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1.
EC-Earth V2.2: description and validation of a new seamless earth system prediction model 总被引：2，自引：2，他引：0
W. Hazeleger X. Wang C. Severijns S. ?tef?nescu R. Bintanja A. Sterl K. Wyser T. Semmler S. Yang B. van den Hurk T. van Noije E. van der Linden K. van der Wiel 《Climate Dynamics》2012,39(11):2611-2629
EC-Earth, a new Earth system model based on the operational seasonal forecast system of the European Centre for Medium-Range Weather Forecasts (ECMWF), is presented. The performance of version 2.2 (V2.2) of the model is compared to observations, reanalysis data and other coupled atmosphere–ocean-sea ice models. The large-scale physical characteristics of the atmosphere, ocean and sea ice are well simulated. When compared to other coupled models with similar complexity, the model performs well in simulating tropospheric fields and dynamic variables, and performs less in simulating surface temperature and fluxes. The surface temperatures are too cold, with the exception of the Southern Ocean region and parts of the Northern Hemisphere extratropics. The main patterns of interannual climate variability are well represented. Experiments with enhanced CO2 concentrations show well-known responses of Arctic amplification, land-sea contrasts, tropospheric warming and stratospheric cooling. The global climate sensitivity of the current version of EC-Earth is slightly less than 1?K/(W?m?2). An intensification of the hydrological cycle is found and strong regional changes in precipitation, affecting monsoon characteristics. The results show that a coupled model based on an operational seasonal prediction system can be used for climate studies, supporting emerging seamless prediction strategies. 相似文献
2.
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
3.
The U.N. Framework Convention on Climate Change’s (UNFCCC’s) Paris Agreement—which aims to limit climate change and increase global resilience to its effects—was a breakthrough in climate diplomacy, committing its Parties to develop and update national climate plans. Yet the Parties to the Agreement have largely overlooked the effect of climate change on ocean-based communities, economies, and ecosystems—as well as the role that the ocean can play in mitigating and adapting to climate change. Because the ocean is an integral part of the climate system, stronger inclusion of ocean issues is critical to achieving the Agreement’s goals. Here we discuss four ocean-climate linkages that suggest specific responses by Parties to the Agreement connected to 1) accelerating climate ambition, including via sustainable ocean-based mitigation strategies; 2) focusing on CO2 emissions to address ocean acidification; 3) better understanding ocean-based mitigation; and 4) pursuing ocean-based adaptation. These linkages offer a more complete perspective on the reasons strong climate action is necessary and inform a systematic approach for addressing ocean issues under the Agreement to strengthen climate mitigation and adaptation. 相似文献
4.
Cornelia Schwierz Christof Appenzeller Huw C. Davies Mark A. Liniger Wolfgang Müller Thomas F. Stocker Masakazu Yoshimori 《Climatic change》2006,79(1-2):31-63
The tasks of providing multi-decadal climate projections and seasonal plus sub-seasonal climate predictions are of significant societal interest and pose major scientific challenges. An outline is presented of the challenges posed by, and the approaches adopted to, tracing the possible evolution of the climate system on these various time-scales. First an overview is provided of the nature of the climate system’s natural internal variations and the uncertainty arising from the complexity and non-linearity of the system. Thereafter consideration is given sequentially to the range of extant approaches adopted to study and derive multi-decadal climate projections, seasonal predictions, and significant sub-seasonal weather phenomena. For each of these three time-scales novel results are presented that indicate the nature (and limitations) of the models used to forecast the evolution, and illustrate the techniques adopted to reduce or cope with the forecast uncertainty. In particular, the contributions (i) appear to exemplify that in simple climate models uncertainties in radiative forcing outweigh uncertainties associated with ocean models, (ii) examine forecast skills for a state-of-the-art seasonal prediction system, and (iii) suggest that long-lived weather phenomena can help shape intra-seasonal climate variability. Finally, it is argued, that co-consideration of all these scales can enhance our understanding of the challenges associated with uncertainties in climate prediction. 相似文献
5.
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
6.
RAMS 2001: Current status and future directions 总被引：21，自引：0，他引：21
W. R. Cotton R. A. Pielke Sr. R. L. Walko G. E. Liston C. J. Tremback H. Jiang R. L. McAnelly J. Y. Harrington M. E. Nicholls G. G. Carrio J. P. McFadden 《Meteorology and Atmospheric Physics》2003,82(1-4):5-29
Summary ?An overview of the Regional Atmospheric Modeling System (RAMS) is presented. We focus on new developments in the RAMS physics
and computational algorithms since 1992. We also summarize some of the recent applications of RAMS that includes synoptic-scale
weather systems and climate studies, to small-scale research using RAMS configured as a large eddy simulation model or to
even flow around urban buildings. The applications include basic research on clouds, cloud systems, and storms, examination
of interactions between tropical deep convective systems and ocean circulations, simulations of tropical cyclones, extreme
precipitation estimation, regional climatic studies of the interactions between the atmosphere and the biosphere or snow-covered
land-surfaces, prototype realtime mesoscale numerical weather prediction, air pollution applications, and airflow around buildings.
Received March 12, 2001; revised August 28, 2001 相似文献
7.
地球系统中的大气圈、水圈、冰雪圈、岩石圈和生物圈构成了气候系统, 气候系统中不同圈层之间的相互作用决定了气候的自然变化。由于人类活动的日益加剧, 对气候系统已经产生了显著影响。气候的自然变化和人类活动导致的气候变化对社会经济的发展以及人民生活的影响日益加大, 并涉及到国家安全、环境外交和可持续发展等一系列重大问题。要认识气候变化及其强迫因素、预测未来气候变化, 最基础的工作是建立针对气候目的涉及到气候系统五大圈层的综合气候观测系统, 以获取所需的高质量资料和相关产品, 提供气候系统变化的详细信息。该文回顾了气候观测系统设计在中国的发展以及中国气象科学研究院在组织设计中国气候观测系统中的作用, 并指出了在建立我国气候观测系统中存在的一些需要改进的方面。在对气候观测系统进行分析的基础上, 指出了与建立气候观测系统相关的10个方面的关键问题, 这些问题包括:气候观测系统的科学需求、气候观测系统的代表性、全面性、规范性、对气候预测和预估及模式发展的支撑性、多学科应用性、社会经济性、资料开放共享性以及气候系统资料的同化再分析和历史资料的抢救。 相似文献
8.
9.
D. J. Bernie E. Guilyardi G. Madec J. M. Slingo S. J. Woolnough 《Climate Dynamics》2007,29(6):575-590
The diurnal cycle is a fundamental time scale in the climate system, at which the upper ocean and atmosphere are routinely
observed to vary. Current climate models, however, are not configured to resolve the diurnal cycle in the upper ocean or the
interaction of the ocean and atmosphere on these time scales. This study examines the diurnal cycle of the tropical upper
ocean and its climate impacts. In the present paper, the first of two, a high vertical resolution ocean general circulation
model (OGCM), with modified physics, is developed which is able to resolve the diurnal cycle of sea surface temperature (SST)
and current variability in the upper ocean. It is then validated against a satellite derived parameterization of diurnal SST
variability and in-situ current observations. The model is then used to assess rectification of the intraseasonal SST response
to the Madden–Julian oscillation (MJO) by the diurnal cycle of SST. Across the equatorial Indo-Pacific it is found that the
diurnal cycle increases the intraseasonal SST response to the MJO by around 20%. In the Pacific, the diurnal cycle also modifies
the exchange of momentum between equatorially divergent Ekman currents and the meridionally convergent geostrophic currents
beneath, resulting in a 10% increase in the strength of the Ekman cells and equatorial upwelling. How the thermodynamic and
dynamical impacts of the diurnal cycle effect the mean state, and variability, of the climate system cannot be fully investigated
in the constrained design of ocean-only experiments presented here. The second part of this study, published separately, addresses
the climate impacts of the diurnal cycle in the coupled system by coupling the OGCM developed here to an atmosphere general
circulation model. 相似文献
10.
N. Krupchatnikov G. A. Platov E. N. Golubeva A. A. Fomenko Yu. Yu. Klevtsova V. N. Lykosov 《Russian Meteorology and Hydrology》2018,43(11):713-721
The results of studies in the area ofnumerical weather prediction and climate theory are presented. These results were obtained by the team of researchers of the Siberian school of mathematical modeling of atmosphere and ocean dynamics established by academician G.I. Marchuk. Academician V.P. Dymnikov played an enormous role in the development of this school by enriching it with new approaches and ideas. His contribution to the Siberian school of mathematical modeling was most strongly pronounced concerning three problems: numerical weather prediction for the Siberian region, the modeling of the climate system dynamics, and the mathematics and theory of climate. 相似文献
11.
A. Henderson-Sellers 《Climatic change》1993,23(4):337-377
A simplified vegetation distribution prediction scheme is used in combination with the Biosphere-Atmosphere Transfer Scheme (BATS) and coupled to a version of the NCAR Community Climate Model (CCM1) which includes a mixed-layer ocean. Employed in an off-line mode as a diagnostic tool, the scheme predicts a slightly darker and slightly rougher continental surface than when BATS' prescribed vegetation classes are used. The impact of tropical deforestation on regional climates, and hence on diagnosed vegetation, differs between South America and S.E. Asia. In the Amazon, the climatic effects of removing all the tropical forest are so marked that in only one of the 18 deforested grid elements could the new climate sustain tropical forest vegetation whereas in S.E. Asia in seven of the 9 deforested elements the climate could continue to support tropical forest. Following these off-line tests, the simple vegetation scheme has been coupled to the GCM as an interactive (or two-way) submodel for a test integration lasting 5.6 yr. It is found to be a stable component of the global climate system, producing only ~ 3% (absolute) interannual changes in the predicted percentages of continental vegetation, together with globally-averaged continental temperature increases of up to + 1.5 °C and evaporation increases of 0 to 5 W m–2 and no discernible trends over the 67 months of integration. On the other hand, this interactive land biosphere causes regional-scale temperature differences of ± 10 °C and commensurate disturbances in other climatic parameters. Tuning, similar to the q-flux schemes used for ocean models, could improve the simulation of the present-day surface climate but, in the longer term, it will be important to focus on predicting the characteristics of the continental surface rather than simple vegetation classes. The coupling scheme will also have to allow for vegetation responses occurring over longer timescales so that the coupled system is buffered from sudden shocks. 相似文献
12.
An assessment of the likely benefits of assimilating in situ temperature (T) and salinity (S) observations from repeat glider transects and surface velocity observations from high-frequency radar arrays into an eddy-resolving ocean model is presented. The deployment of new shelf observation platforms around Australia is being undertaken through the Australian Integrated Marine Observing System program. In this study, various options for an observing system along the coast of New South Wales, Australia, are assessed for their benefits to an ocean forecast and reanalysis system. The forecast system considered here uses ensemble optimal interpolation (EnOI) for data assimilation. Using error estimates from the EnOI scheme, estimates of the theoretical analysis errors are calculated for different observing systems that include a range of remotely sensed and in situ observations. The results demonstrate that if HF radar observations are assimilated along with the standard components of the global ocean observing system, the analysis errors are likely to reduce by as much as 80% for velocity and 60% for T, S and sea-level in the vicinity of the observations. Owing to the relatively short along-shore decorrelation length-scales for T and S near the shelf, the glider observations are likely to provide the forecast system with a more modest gain. 相似文献
13.
《Dynamics of Atmospheres and Oceans》2010,49(1-3):121-142
An assessment of the likely benefits of assimilating in situ temperature (T) and salinity (S) observations from repeat glider transects and surface velocity observations from high-frequency radar arrays into an eddy-resolving ocean model is presented. The deployment of new shelf observation platforms around Australia is being undertaken through the Australian Integrated Marine Observing System program. In this study, various options for an observing system along the coast of New South Wales, Australia, are assessed for their benefits to an ocean forecast and reanalysis system. The forecast system considered here uses ensemble optimal interpolation (EnOI) for data assimilation. Using error estimates from the EnOI scheme, estimates of the theoretical analysis errors are calculated for different observing systems that include a range of remotely sensed and in situ observations. The results demonstrate that if HF radar observations are assimilated along with the standard components of the global ocean observing system, the analysis errors are likely to reduce by as much as 80% for velocity and 60% for T, S and sea-level in the vicinity of the observations. Owing to the relatively short along-shore decorrelation length-scales for T and S near the shelf, the glider observations are likely to provide the forecast system with a more modest gain. 相似文献
14.
General circulation model experiments designed to estimate the magnitude and structure of internally generated variability and to help understand the mechanisms underlying this variability are described. The experiments consist of three multi-century integrations of a rhomboidal 15, 9 level, version of the Center for Ocean-Land-Atmosphere Studies atmospheric general circulation model: a run with fixed sea surface temperatures and equinox solar radiation, a run with seasonally varying climatological sea surface temperatures and seasonally varying solar forcing, and a run with seasonally varying solar forcing in which the state of the ocean is predicted by a 3° by 3°, 16 vertical level, nearly global domain version of the Geophysical Fluid Dynamics Laboratory Modular Ocean Model. No flux correction is used in the coupled model integration. Selected surface fields of the three runs are compared to each other as well as to the observed climate. Statistical properties of variability on interannual time scales are compared between the runs. Evidence is presented that climate time scale variability in the simulations is produced by random weather time scale forcing due to the integrating effect of elements of the system with long memories. The importance of ocean variability for land climate variability is demonstrated and attributed to both the memory effect and coupled atmosphere-ocean instability. 相似文献
15.
短期气候预测依据大气科学原理,运用气候动力学、统计学等手段,在研究气候异常成因的基础上对未来气候趋势进行预测。虽然目前我国短期气候预测的水平还不高,但短期气候预测是国家经济发展和防灾减灾的迫切需求,提高预测准确率是气象科研和业务人员的重要任务。该文从海洋、积雪等外强迫信号及大气环流大尺度变动等大气内部特性等角度概述了短期气候预测的物理基础,简要回顾了近60年来我国短期气候预测的发展历程,并介绍了作者近十几年来研制短期气候预测客观统计学及统计与动力学相结合预测模型的主要思路。 相似文献
16.
Angelo Rubino 《Theoretical and Applied Climatology》2011,106(3-4):473-479
Based on issues recently raised on the future of climate science, I present here a critical discussion which embraces the crucial aspects of the communication between climate scientists and laypersons, of the role confusing statements may exert on possible advancements in climate research, and of scientific priorities in climate science. I start distinguishing between different applications of climate models and identifying confusing uses of the words ??prediction?? and ??projection?? in recent discussions on climate modeling. Numerical models like those used in climate simulations are not assimilable to truly theories, nor can obtained results be considered as truly experimental evidences. Hence, it is hard to envisage the feasibility of crucial experiments through climate models. Increasing model resolution and complexity, although undoubtedly helpful for many applications related to a deeper understanding of the complex climate system and to substantial improvement of short-term forecasts, is not destined to change this fundamental limitation, to tackle the impossibility of predicting prominent climate forcings and to facilitate result comparisons against observations. Finally, as an example describing possible alternative resource allocations, I propose to devote more energy to strengthen the observational part of climate research, to focus on midterm forecasts, and to implement a new employment policy for climate scientists. In particular, through an increased and truly global in situ and remote sensing climate observing network, crucial experiments could emerge to challenge the fundamental basis of the conjecture of a great anthropogenic climate change, which, as known, is largely based on high climate sensitivities simulated by numerical models. 相似文献
17.
We present a method for constraining key properties of the climate system that are important for climate prediction (climate
sensitivity and rate of heat penetration into the deep ocean) by comparing a model's response to known forcings over the twentieth
century against climate observations for that period. We use the MIT 2D climate model in conjunction with results from the
Hadley Centre's coupled atmosphere–ocean general circulation model (AOGCM) to determine these constraints. The MIT 2D model,
which is a zonally averaged version of a 3D GCM, can accurately reproduce the global-mean transient response of coupled AOGCMs
through appropriate choices of the climate sensitivity and the effective rate of diffusion of heat anomalies into the deep
ocean. Vertical patterns of zonal mean temperature change through the troposphere and lower stratosphere also compare favorably
with those generated by 3-D GCMs. We compare the height–latitude pattern of temperature changes as simulated by the MIT 2D
model with observed changes, using optimal fingerprint detection statistics. Using a linear regression model as in Allen and
Tett this approach yields an objective measure of model-observation goodness-of-fit (via the residual sum of squares weighted
by differences expected due to internal variability). The MIT model permits one to systematically vary the model's climate
sensitivity (by varying the strength of the cloud feedback) and rate of mixing of heat into the deep ocean and determine how
the goodness-of-fit with observations depends on these factors. This provides an efficient framework for interpreting detection
and attribution results in physical terms. With aerosol forcing set in the middle of the IPCC range, two sets of model parameters
are rejected as being implausible when the model response is compared with observations. The first set corresponds to high
climate sensitivity and slow heat uptake by the deep ocean. The second set corresponds to low sensitivities for all magnitudes
of heat uptake. These results demonstrate that fingerprint patterns must be carefully chosen, if their detection is to reduce
the uncertainty of physically important model parameters which affect projections of climate change.
Received: 19 April 2000 / Accepted: 13 April 2001 相似文献
18.
Sustaining agricultural production and food security in Southern Africa: an improved role for climate prediction? 总被引：1，自引：0，他引：1
Emma Archer Elijah Mukhala Sue Walker Maxx Dilley Kennedy Masamvu 《Climatic change》2007,83(3):287-300
Livelihoods and household food security in the Southern African region can be extremely vulnerable to the negative effects
of climate stress as shown by the 2002–2004 ‘complex emergency.’ Climate prediction may prove a valuable resource in mitigating
these effects. If climate prediction is applied successfully, it may be able to help guide responses in populations at risk
to reduce vulnerability to climate stress. The study presented here seeks to understand what would constitute an improved
role for climate prediction in contributing to sustaining agricultural production and food security in Southern Africa. Investigation
undertaken during the 2002/2003 rainy season under regional conditions of elevated disaster risk shows, however, that a number
of weaknesses and gaps persistently characterize climate information systems in the Southern African region, and constrain
such systems’ ability to benefit key sectors, particularly agriculture. The stakeholder identification of such gaps forms
the basis for distilling concrete recommendations to improve process and organizational efficiency. Such recommendations,
while developmental, should better enable institutions and stakeholders involved in climate prediction to fulfill their potential
in supporting development of successful adaptation strategies in populations and sectors at risk. 相似文献
19.
提出一种气候场的主分量逐步回归预测模型,该模型将气候场的预测变成对该场主分量的预测。提取对气候场变化有重要影响的500 hPa高度、太平洋及印度洋海温和全球海平面气压等含不同区域不同季节的因子场的前若干个含高信息量的优质主分量因子。通过相关筛选和双重检验逐步回归,建立气候场的主分量的预测方程,由此就建立气候场与多个因子场之间的联系,但是模型却仍然保持着两个场相关的特点。根据气候场的特征向量的近似不变性,将其与主分量配合进行反算,从而得到气候场的预测。以广东汛期降水预测作为试验例子,计算了它的主分量,分析了它的时空分布特征及分类,对2003—2005年的分布作预测并与实测分布作比较及进行误差检测,发现预测效能显著。有关预测的年限、区域范围、要素和因子的物理背景等问题有待进一步研究。 相似文献
20.
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