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基于通量距平的大气—海洋—海冰耦合模式 总被引：1，自引：0，他引：1
该文是基于月平均通量距平（ＭＦＡ）的海报耦合方案及其在４个海气耦合的环流模式中应用情况的一个综合评述，这些模式的实施情况表明，由于采用精细化了参考通量，修正的ＭＦＡ（ＭＭＦＡ）比它的原型具有为稳定的控制气候漂移的能力。 相似文献
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利用NCAR CCM2十八层全球大气环流谱模式和IAP／LASG OGCM二十层全球大洋环流模式，设计了一个通量场再分析同步耦合方案FRAC（Flux Re—Analysis Coupling scheme），建立了全球海气耦合模式系统（NIM／COAMS）。利用EOF理论消除分量模式通量在海气非线性相互作用过程中产生的高频振荡，保留模式通量场的主要成分．使模式误差不致被迅速放大。模拟结果表明，积分前10a全球平均海表温度仅上升0．1℃，全球平均表面温度仅上升0．3℃，以后基本保持不变，模式没有出现明显的气候漂移，50a积分显示，模式对气候态的模拟与观测基本一致，部分结果优于未耦合模式。 相似文献
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热带海洋全球大气计划的海气耦合响应试验（ＣＯＡＲＥ）Ｊ．Ｓ．Ｇｏｄｆｒｅｙ（澳大利亚）１引言１９９２年１１月－１９９３年２月，在巴布亚新几内亚以东地区进行了热带海洋全球大气计划（ＴＯＧＭ）的海气耦合响应试验（ＣＯＡＲＥ），这是人们已进行的阵容最强的海... 相似文献
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利用热带太平洋海气耦合异常模式的３０ａ模拟结果，对模式ＥＮＳＯ的变化性及多重时间尺度过程进行了细致分析，建立了一ＥＮＳＯ循环多重时间尺度过程相互作用的非线性相似（Ａｎａｌｏｇ）模型，并提出了ＥＮＳＯ循环主周期形成的一种可能机制。指出：和观测事实类似，模式ＥＮＳＯ过程确实涉及到三种时间尺度，即３—４ａ主周期振荡（ＬＦ）、准两年振荡（ＱＢ）和年循环（ＡＣ）；其中，ＱＢ过程是线性海气耦合系统的本征模态，年循环（ＡＣ）对其形成没有本质的影响；３—４ａ主周期振荡（ＬＦ）是一非线性系统的自激振荡现象，其形成是线性系统的本征模即ＱＢ过程通过非线性机制尤其是通过大气辐合反馈加热的“单向性”过程在ＱＢ的暖态产生的减频增幅所致；平均年循环（ＡＣ）虽然不能对ＥＮＳＯ循环形成有本质影响，但它可明显影响ＥＮＳＯ循环的具体振幅和位相，使得ＥＮＳＯ循环具有明显的不规则性并对季节循环具有明显的“锁相”特征；ＥＮＳＯ变化性确是ＬＦ、ＱＢ以及ＡＣ多重时间尺度相互作用形成的。本文提出的ＥＮＳＯ循环时间尺度选择机制不仅解释了主周期振荡的形成过程，而且也较好地解释了ＥＮＳＯ变化的谱，因此，这一机制更接近于观测事实。 相似文献
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利用最佳信号检测理论于１００年的地面温度资料中寻找与４个特定辐射强迫的气候响应。分析中所用的资料来源于地球上的３６个单元，而且被限定在０．０６～０．１３ｒ／ａ的频带（１６．６７～７．６９ａ）内。估算了气候对太阳变率、火山气溶胶、温室气体和人类活动产生的气溶胶的响应强度。最佳滤波器由一个用二维能量平衡模式（ＥＢＭ）计算出的信号波形组成。最佳权重是用地球物理流体动力学实验室（ＧＦＤＬ）和Ｍａｘ－Ｐｌａｎｋ研究所耦合的海气模式的１０００年控制试验和噪声强迫的ＥＢＭ１００００年控制试验计算得到的。作者还利用了ＧＦＤＬ混和层模式的１０００年试验。结果这４个独立的模式有合理的一致性。我们发现，垂直于其他信号的火山分量非常强，且很显著。与此类似，垂直于其他信号的温室气体分量也非常强且很显著。当所有４个气候强迫组合时，气候响应超过噪音水平的３个标准差。这些发现被认为是人类活动引起的气候变化的有力证据 相似文献
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本工作发展了一个用于研究热带海洋大气系统相互作用和ＥｌＮｉｎ～ｏ／ＳｏｕｔｈｅｒｎＯｓ－ｃｉｌａｔｉｏｎ动力过程的混合型（ｈｙｂｒｉｄ）耦合模式，其中的大气部分为一个由一阶斜压模表示的自由大气和混合行星边界层所组成的简单热带大气模式（区域为热带太平洋：１２０°Ｅ～８０°Ｗ，３０°Ｎ～３０°Ｓ；水平分辨率为２°×２°），海洋部分为大气物理研究所高分辨率自由表面热带太平洋环流模式（经纬圈方向水平分辨率分别为１°和２°，垂直方向分为不等距的１４层）。两模式间的耦合是这样进行的：简单大气模式计算出海表风应力，热通量由松弛公式计算，淡水通量（蒸发与降水之差）由观测资料给定，它们一起作为海洋环流模式（ＯＧＣＭ）的强迫场；而ＯＧＣＭ计算出海表温度（ＳＳＴ），在其以外地区给定观测到的气候海表温度或陆地温度，作为大气模式的边界条件。本文给出采用逐日、同步耦合方案时模式对热带太平洋气候态模拟结果，表明未采用任何通量修正（ｆｌｕｘｅｓｃｏｒｒｅｃｔｉｏｎ），耦合模式未出现气候漂移（ｃｌｉｍａｔｅｄｒｉｆｔ）现象，并且非常逼真地再现了热带太平洋气候态，特别是海表风场及相伴随的辐合带和降水、海表温度和流场及它们的季节变化。文中还进行 相似文献
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海气相互作用研究进展——美国海－气相互作用第九届学术会内容简介吴国雄（中国科学院大气物理研究所ＬＡＳＧ①,北京１０００８０）海气相互作用不仅影响着风暴、气旋等短期天气过程,还影响着季风、大气涛动以及年代际变化等气候过程。ＡＭＳ第７８届年会期间举办了第... 相似文献
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南沙海域大气湍流通量输送特征分析 总被引：23，自引：1，他引：23
利用１９９４年９月在南沙群岛的渚碧礁（１０°５２′Ｎ，１１４°０４′Ｅ）观测的湍流资料，采用涡旋相关法计算，给出了南沙海域的曳力系数，动量通量，感热通量和潜热通量，并与其它海气相互作用实验及ＨＥＩＦＥ的结果作了比较，结果表明，该海域的曳力系数ＣＤ＝（１．５４±０．２４）×１０＾－３。大气向海洋输送动量通量与水平风速挟方成正比，该海区无论白在还是晚上都是将其贮存的热量以潜热或感热的形式输送到大气中。 相似文献
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The effect of employing flux adjustments on the climatic response of an idealized coupled model to an imposed radiative forcing
is investigated with two coupled models, one of which employs flux adjustments. A linear reduction (to the planetary longwave
flux) of 4 W/m2 is applied over a 70 y period and held constant thereafter. Similar model responses are found (during the initial 70 y period)
for global-scale diagnostics of hemispheric air temperature due to the nearly linear surface-air temperature response to the
radiative forcing. Significant regional scale differences do exist, however. As the perturbation away from the present climate
grows, basin-scale diagnostics (such as meridional overturning rates) begin to diverge between flux adjusted and non-flux
adjusted models. Once the imposed radiative forcing is held constant, differences in global mean air temperature of up to
0.5 °C are found, with large regional-scale differences in air temperature and overturning rates within the North Atlantic
and Southern Ocean. Two additional experiments with the flux adjusted model (beginning from points further along the control
integration) suggest that the elimination of much of the coupling shock before the radiative forcing is applied leads to results
slightly closer to the non-flux adjusted case, although large differences still persist. In particular a dipole structure
indicating an enhanced warming within the Pacific sector of the Southern Ocean, and cooling within the Atlantic sector is
not reproduced by the flux adjusted models. This disparity is intimately linked to the Southern Ocean overturning cell along
with the flux adjustments employed as well as the drift arising from coupling shock. If a similar form of sensitivity exists
in more realistic coupled models, our results suggest: (1) perturbation experiments should not be undertaken until after the
coupled model control experiment is carried out for several hundred years (thereby minimizing the coupling shock); (2) care
should be exercised in the interpretation of regional-scale results (over the ocean) in coupled models which employ flux adjustments;
(3) care should also be taken in interpreting even global-scale diagnostics in flux adjusted models for large perturbations
about the present climate.
Received: 15 November 1996 / Accepted: 4 June 1997 相似文献
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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
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Connection between atmospheric latent energy and energy fluxes simulated by nine CMIP5 models 
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下载免费PDF全文 The atmospheric latent energy and incoming energy fluxes of the atmosphere are analyzed here based on the historical simulations of nine coupled models from the Coupled Model Intercomparison Project Phase 5(CMIP5)and two reanalysis datasets.The globally averaged atmospheric latent energy is found to be highly correlated with several types of energy flux,particularly the surface latent heat flux,atmosphere absorbed solar radiation flux,and surface net radiation flux.On the basis of these connections,a hydrological cycle controlled feedback(HCCF)is hypothesized.Through this feedback,the atmosphere absorbed solar radiation is enhanced and causes intensification of the surface latent heat flux when the atmospheric latent energy is abnormally strong.The representativeness of the HCCF during different periods and over different latitudinal zones is also discussed.Although such a feedback cannot be confirmed by reanalysis,it proves to be a common mechanism for all the models studied. 相似文献
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A systematic comparison of observed and modeled atmospheric surface heat and momentum fluxes related to sea surface temperature
(SST) variability on interannual time scales in the tropical Pacific is conducted. This is done to examine the ability of
atmospheric general circulation models (AGCMs) in the Atmospheric Model Intercomparison Project (AMIP) to simulate the surface
fluxes important for driving the ocean on interannual time scales. In order to estimate the model and observed response to
such SST variability, various regression calculations are made between a time series representing observed ENSO SST variability
in the tropical Pacific and the resulting surface flux anomalies. The models exhibit a range of differences from the observations.
Overall the zonal wind stress anomalies are most accurately simulated while the solar radiation anomalies are the least accurately
depicted. The deficiencies in the solar radiation are closely related to errors in cloudiness. The total heat flux shows some
cancellation of the errors in its components particularly in the central Pacific. The performance of the GCMs in simulating
the surface flux anomalies seems to be resolution dependent and low-resolution models tend to exhibit weaker flux responses.
The simulated responses in the western Pacific are more variable than those of the central and eastern Pacific but in the
west the observed estimates are less robust as well. Further improvements in atmospheric GCM flux simulation through better
physical parametrization is clearly required if such models are to be used to their full potential in coupled modeling and
climate forecasting.
Received: 24 August 1999 / Accepted: 11 September 2000 相似文献
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为提高研究区域的降尺度效果,基于地理加权回归法(Geographically Weighted Regression,GWR),选取全球降水计划(Global Precipitation Measurement,GPM)3IMERGM产品,以数字高程模型(Digital Elevation Model,DEM)作为控制解释变量,将其分别与解释变量水汽通量散度、气温构建两个降尺度模型、与解释变量归一化植被指数(Normalized Difference Vegetation Index,NDVI)构建对照降尺度模型,对浙江省进行降尺度研究。利用研究区域内气象站点的实测数据,对由不同解释变量构建的3个降尺度模型的降尺度结果进行对比分析及精度验证。结果表明:构建的3个降尺度模型中,引入解释变量水汽通量散度构建的降尺度模型的综合效果优于其余两种模型,水汽通量散度较NDVI、气温更适合作为解释变量。构建的降尺度模型有效地提高了GPM数据的空间分辨率(由0.1°提升至1 km),降尺度数据维持了精度且能够更真实反映研究区域内的降水量分布情况。 相似文献
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The Role of the Aerosol Indirect Effect in the Northern Indian Ocean Warming Simulated by CMIP5 Models 下载免费PDF全文
下载免费PDF全文 The northern Indian Ocean （NIO） experienced a decadal-scale persistent warming from 1950 to 2000, which has influenced both regional and global climate. Because the NIO is a region susceptible to aerosols emis- sion changes, and there are still large uncertainties in the representation of the aerosol indirect effect （ALE） in CMIP5 （Coupled Model Intercomparison Project Phase 5） models, it is necessary to investigate the role of the AIE in the NIO warming simulated by these models. In this study, the authors select seven CMIP5 models with both the aerosol direct and indirect effects to investigate their performance in simulating the basin-wide decadal-scale NIO warming. The results show that the decreasing trend of the downwelling shortwave flux （FSDS） at the surface has the major damping effect on the SST increasing trend, which counteracts the warming effect of greenhouse gases （GHGs）. The FSDS decreasing trend is mostly contrib- uted by the decreasing trend of cloudy-sky surface downwelling shortwave flux （FSDSCL）, a metric used to measure the strength of the AIE, and partly by the clear-sky surface downwelling shortwave flux （FSDSC）. Models with a relatively weaker AIE can simulate well the SST increasing trend, as compared to observation. In contrast, models with a relatively stronger AIE produce a much smaller magnitude of the increasing trend, indicat- ing that the strength of the AIE in these models may be overestimated in the NIO. 相似文献
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Vertical heat fluxes induced by mesoscale thermally driven circulations maycontribute significantly to the subgrid-scale fluxes in large-scale models (e.g.,general circulation models). However, they are not considered in these modelsyet. To gain insight into the importance and possible parameterisation of themesoscale flux associated with slope winds, an analytical (conceptual) modelis developed to describe the relationship between the mesoscale heat flux andatmospheric and land-surface characteristics. The analytical model allows usto evaluate the mesoscale flux induced by slope winds from only a few profilemeasurements within a domain. To validate the analytical model the resultingheat flux profiles are compared to profiles of highly resolved wind and temperaturefields obtained by simulations with a mesoscale numerical model.With no or moderate synoptic wind the mesoscale heat flux generated by the slopewind circulation may be as large as, or even larger than, the turbulent fluxes at thesame height. At altitudes lower than the crest of the hills the mesoscale flux is alwayspositive (upward). Generally it causes cooling within the boundary layer and heatingabove. Despite the simplifications made to derive the analytical model, it reproducesthe profiles of the mesoscale flux quite well. According to the analytical model, themesoscale heat flux is governed by the temperature deviation at the slope surface, thedepth of the slope-wind layer, the large-scale lapse rate, and the wavelength of thetopographical features. 相似文献
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The generation and dissipation of SST anomalies is mediated by the covariability of SST and surface heat fluxes. The connection between the variability of heat flux (including its radiative and turbulent components) and that of SST is investigated using the NCEP-NCAR and ERA-40 reanalyses and the CMIP3 multi-model collection of climate simulations. The covariance patterns of SST and heat flux are broadly similar in the two reanalyses. The upward heat fluxes are positively correlated with the SST anomalies in the tropics, the northern Pacific mid-latitudes, and over the Gulf Stream, and negatively correlated in the northern subtropics and the SPCZ region. Common covariance features are seen in all climate models in the tropics and the subtropics, while covariances differ considerably among models at northern mid-latitudes, where weak values of the ensemble mean are seen. Lagged covariances are broadly similar in the two reanalyses and among the models, implying that heat flux feedback is also similar. The heat flux feedback parameter is determined from the lagged cross-covariances together with the auto-covariance of SST. Feedback is generally negative and is dominated by the turbulent component. The strongest feedback is found at mid-latitudes in both hemispheres, with the largest values occurring in the western and central portions of the oceans with extensions to higher latitudes. The latter are also areas with large inter-model differences. The heat flux feedback strengthens in winter and fall and weakens in spring and summer. The magnitudes of the annual and seasonal feedback parameters are slightly weaker in most models compared to the reanalysis-based estimates. The mean model feedback parameter has the best pattern correlation and the smallest mean square difference compared to the reanalysis-based values, although spatial variances are weak. Model resolution shows no relationship with the heat flux feedback parameters obtained from model results. The SST-heat flux covariance is decomposed into components associated with surface heat flux feedback and atmospheric forcing processes. Heat flux feedback dominates over the atmospheric forcing and heat flux damps SST anomalies on average at northern Pacific mid-latitudes and southern Atlantic mid-latitudes; while the reverse occurs in the SPCZ and northern Atlantic mid-latitudes. 相似文献
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利用NOAH(The Community Noah Land Surface Model)、SHAW(Simultaneous Heat and Water)和CLM(Community Land Model)3个不同的陆面过程模式及兰州大学(Semi-Arid Climate Observatory and Laboratory,SACOL)2007年的观测资料,对黄土高原半干旱区的陆面过程进行了模拟研究。通过与观测值间的对比,考察不同陆面过程模式在半干旱区的适用性。研究结果表明:3个模式在半干旱区的模拟性能有较大差异。其中,CLM模式模拟的20 cm以上的浅层土壤温度最优,SHAW模式模拟的深层土壤温度最优;SHAW模式模拟的土壤含水量与观测值最为接近,而NOAH和CLM模式模拟值有较大偏差;3个模式均能较好地模拟地表反射辐射,其中SHAW模式模拟值与观测值的偏差最小;对地表长波辐射的模拟,CLM模式的模拟最优;3个模式均能较好地反映感热、潜热通量的变化趋势,其中CLM模式对感热的模拟性能优于其他两个模式,在有降水发生后的湿润条件下,CLM模式对潜热的模拟性能最优,而无降水的干燥条件下,CLM模式的模拟偏差最大,NOAH模式对冬季潜热的模拟最优。总体而言,CLM模式能够更好地再现半干旱区地气之间的相互作用,但模式对土壤含水量及干燥条件下的潜热通量的模拟较差,模式对半干旱区陆气间的水文过程还有待进一步的研究和改进。 相似文献
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Dongchul Kim Christopher P. Loughner Melanie A. Wetzel Wendy S. Goliff William R. Stockwell 《Journal of Atmospheric Chemistry》2007,57(1):59-71
Photolysis rate parameters depend upon solar actinic flux and chemical species dependent quantum yields and cross sections.
Spectrally resolved measurements of actinic flux should be preferred over flux derived from models for the analysis of field
observations. Actinic flux can be difficult to derive from the irradiance measurements of flat-plate radiometers. It is also
difficult to estimate from models due to uncertainties in the ozone column, aerosol concentrations and distributions, cloud
cover, optical depth and surface albedo. A series of actinic flux measurements were performed at Storm Peak Laboratory (3,210 m
above sea level), Colorado, United States with spectroradiometers during the wintertime (January 07–10, 2004). The site is
relatively remote with a clean atmosphere and during the wintertime the ground is generally covered by fresh snow with a high
albedo. The actinic flux measurements were used to estimate the photolysis rate parameters of ozone, nitrogen dioxide and
formaldehyde. The measured actinic flux and the photolysis rate parameters derived from the flux were compared to calculations
using the Tropospheric Ultraviolet-Visible Model (TUV), version 4.2 (Madronich and Flocke, 1998). The TUV modeled actinic
flux, the measured flux and the photolysis rate parameters derived from them had similar temporal patterns. However there
were significant differences in their magnitude due to uncertainties in the data available to initialize the TUV model and
the calibration of the spectroradiometer. 相似文献