共查询到19条相似文献，搜索用时 140 毫秒
1.
海温强迫下的东亚夏季大气环流潜在可预报性特征 总被引：2，自引：2，他引：0
利用大气环流模式NCARCAM3,进行22a（1979—2000年）、每年8个初值的集合试验,并采用方差分析方法,研究了观测海温强迫下东亚夏季大气环流的潜在可预报性。结果表明,夏季东亚地区海平面气压场的潜在可预报性总体偏低,在中国区域呈东南高、西北低的分布特征;850hPa纬向风场、对流层500～200hPa平均温度场和500hPa位势高度场在低纬度地区的潜在可预报性明显高于中高纬度地区。500hPa位势高度场的潜在可预报性较高,东亚大部分地区大于0.5,尤其华南地区大于0.7。夏季东亚500hPa位势高度场的潜在可预报性具有明显的年际变化特征,并与夏季南海海温异常关系密切。与正常年份相比,在夏季南海海温偏暖或者偏冷年,东亚500hPa位势高度场的潜在可预报性较高 相似文献
2.
土壤湿度影响中国夏季气候的数值试验 总被引：10，自引：0，他引：10
利用"全球土壤湿度计划第2阶段"提供的土壤湿度资料强迫区域气候模式RegCM3,通过数值试验讨论了土壤湿度对东亚夏季气候模拟效果的影响。结果表明,合理考虑土壤湿度的作用,能够提高区域气候模式对中国夏季降水和2 m气温的空间分布型及逐日变化的模拟效果;模拟结果与观测的相关分析显示,降水和2 m气温的年际变化都得到了有效改进,这种改进在气温上尤为明显。不过上述改进具有区域依赖性。数值试验结果表明,气温对土壤湿度的敏感性强于降水,这也从一个侧面说明提高降水模拟效果的难度。总体而言,合理的土壤湿度能够提高区域气候模式对中国夏季气候的模拟能力。因此,合理描述土壤湿度的变化,是提高中国夏季气候预报技巧的潜在途径之一。 相似文献
3.
基于NCAR大气模式CAM3.1模式,设计了有、无土壤湿度年际异常两组试验对中国区域近40a(1961-2000年)气候进行了模拟。从气候态和年际变率的角度,通过分析两组试验的差值场来探讨土壤湿度年际异常对气候模拟的影响,并初步探讨了影响的可能机制。结果表明:模式模拟的温度和降水对土壤湿度的年际异常非常敏感,土壤湿度的年际变化对中国春夏季气候及其年际变率均有显著影响。当不考虑土壤湿度年际异常时,模式模拟的春夏季平均温度、最高温度、最低温度在我国大范围内降低,春夏季降水在东部大部分地区明显减少,西部增加。而模式模拟的春夏季温度、降水年际变率在中国大部分地区减弱。但当考虑土壤湿度的年际变化,则能在一定程度上提高模式对气候年际变率的模拟能力。在进一步分析表明土壤湿度年际异常时,主要通过改变地表能量通量和环流场,对温度、降水产生影响。当不考虑土壤湿度年际异常时,地表净辐射通量减少,地表温度降低,感热通量减少。感热通量差值场的空间变化和温度差值场的空间变化一致,感热通量对温度有一定影响。而潜热通量差值场的空间变化和降水的差值场的空间变化一致,可见降水受地表潜热通量的影响。土壤湿度年际异常引起的环流场的变化也是导致气候变化的原因之一,地表能量和环流场年际变率的改变对春夏季气候年际变率存在一定影响。 相似文献
4.
基于动力气候模式进行月一季尺度预报的“两步法”思想,提出一种新的预报海温场统计模型,并以该统计模型预报的海温场驱动NCAR CAM3.1模式对1981-2000年月时间尺度的东亚500 hPa高度距平场进行客观回报试验;在此基础上,提出了对预报结果的订正方法。结果表明:统计预报海温模型的预报海温场能够反映出全球海温空间分布的基本特征,并对表征ENSO事件的Ni?o3.4区海温变化的预报能力较强。该统计模型预报的海温场驱动的CAM3.1模式可以较好地预报出东亚500 hPa环流的主要分布特征,试验表明:适当的统计订正方法可以在一定程度上提高CAM3.1模式对东亚夏季500 hPa环流背景的预报技巧。 相似文献
5.
对比国家气候中心耦合模式BCC_CSM1.1提交CMIP5的历史（Historical）试验和年代际（Decadal）回报试验对中国气候及其年代际变化的模拟。结果表明,Decadal试验回报的中国降水气候分布更接近观测,回报的中国东部气温和降水的年代际距平误差比Historical试验减小明显。对于发生在20世纪70年代末的中国东部降水年代际变化,Decadal试验能回报出长江中下游降水增多的特征,但Historical试验模拟的降水变化与观测相反。由于Decadal试验和Historical试验的区别之一是后者利用观测海温资料进行了初始化,为了探讨观测海温信息的重要性,进一步将Decadal试验与恢复（Nudging）试验（即模式积分过程中,模拟海温始终向观测海温恢复）的模拟结果进行对比。发现Nudging试验能够较好地模拟出“南涝北旱”型降水变化,也能够模拟出相应的东亚急流增强且偏南的特征。这表明气候模式对海温的回报能力是影响其对东亚气候年代际异常模拟的一个重要因素。 相似文献
6.
东亚夏季风和中国东部夏季降水年代际变化的模拟 总被引：4，自引：2，他引：4
利用中国科学院大气物理研究所发展的第四代大气环流模式模拟了1970年代末东亚夏季风和相关的中国东部夏季降水年代际变化。结果表明,在给定的观测海温强迫下,模式能模拟出东亚夏季风的年代际减弱及 相关的环流场变化,包括东亚沿海的偏北风异常以及西太平洋副高的形态变化,模式还较好再现了中国东部夏季降水的雨型变化,即长江流域降水偏多,而华北和华南偏少,但位置略偏南。基于奇异值分解(SVD)的分析表明,热带海洋变暖是这次东亚夏季风的年代际减弱的主要因素,这与太平洋年代际振荡(PDO)在1970年代末期的位相转变有关。此外,模式还较好模拟了长江流域的变冷趋势,进而减弱了海陆温差,使东亚夏季风减弱。 相似文献
7.
区域海气耦合模式对中国夏季降水的模拟 总被引：8，自引：0，他引：8
以区域气候模式RegCM3和普林斯顿海洋模式POM为基础,建立了一个区域海气耦合模式,对1963-2002年中国夏季气候进行模拟,重点分析该耦合模式对中国夏季降水的模拟性能以及降水模拟改进的可能原因.结果表明:耦合模式对中国夏季雨带分布的模拟明显优于控制试验(单独的大气模式),对长江流域以及华南降水的模拟性能改进尤为明显,同时耦合模式能够更为真实地刻画中国东部地区汛期雨带的移动.对降水的年际变化分析发现,耦合模式模拟的1963-2002年中国夏季降水年际变率与观测吻合,模拟的夏季长江流域降水与观测降水相关系数达到0.48,模拟的华南夏季降水与观测的相关系数达到0.61,而控制试验结果与观测降水的相关系数均较小.对中国东部长江流域夏季降水与近海海温的相关分析表明,用给定海温驱动的大气模式,并不能正确模拟出中国东部夏季降水与海温的关系,而耦合模式能够较好地模拟出长江流域与孟加拉湾、南海以及黑潮区海温的关系,与GISST(全球海冰和海表温度)和观测降水相关关系一致.对水汽输送通量的分析发现,控制试验模拟的水汽输送路径与NCEP/NCAR再分析资料相比差别较大,耦合模式模拟的来自海洋上的水汽输送强度和路径与NCEP/NCAR再分析资料一致,提高了耦合模式对水汽输送的模拟能力,从而改善了模式对华南以及长江流域降水的模拟. 相似文献
8.
CAM3模式海气湍流通量参数化的改进及其应用 总被引：1，自引：0，他引：1
通过对流性阵风参数化方法,在CAM3原有海气湍流通量参数化方案(CAM3方案)中引入边界层自由对流和降水深对流对海表湍流通量的贡献,改进了CAM3模式的海气湍流通量参数化方案(CAM3 ME方案).在此基础上,利用观测海温积分改进的CAM3模式,分析改进模式对冬(DJF)、夏季(JJA)大气环流异常的模拟性能.结果表明,采用改进的海气湍流通量参数化方案,模式对冬(DJF)、夏季(JJA)大气环流异常年际变化的模拟能力有了很大提高,尤其是冬季(DJF)北太平洋和北美大陆地区以及夏季(JJA)南半球海洋上空. 相似文献
9.
文章扼要介绍了基于LASG/IAP大气环流谱模式(SAMIL)的气候系统模式的新版本FGOALS-s的发展和结构。出于发展一个在东亚季风模拟方面有一定优势的气候系统模式之目的,FGOALS-s的大气模式分量SAMIL采用了较高的水平分辨率R42,这相当于2.8125°(经度)×1.66°(纬度),高于三角截断T42的分辨率。对FGOALS-s在模拟大气、陆面、海洋和海冰的气候平均态,以及主要的年际变率信号方面的能力进行了检验。分析表明,FGOALS-s成功地控制了气候漂移趋势,能够较为真实地模拟大气、海洋和陆面的气候平均态,特别是受益于大气模式的较高分辨率,由中国西南向东北延伸的夏季风雨带的分布,在模式中得到较为真实的再现,表明该模式在东亚夏季风的模拟上具有较强能力。耦合模式能够成功再现El Ni~no事件的非规则周期变化,但是其年际变化的振幅较之观测要弱。赤道中西太平洋年际变率的强度较之赤道中东太平洋要强。在中高纬度,模式模拟的北大西洋涛动模态,在空间分布上与观测接近。FGOALS-s模式存在的主要问题,是模拟的热带海温偏冷、而中纬度海温则偏暖,原因是模式模拟的云量分布存在偏差,它直接影响到海表的净热通量收支。模式模拟的北大西洋高纬度地区的海温明显偏冷,令该地区的年平均海冰分布的范围明显偏大;然而受南极周边海温偏高影响,南极洲周围的海冰范围则偏少。FGOALS-s的未来工作重点,宜放在大气模式的云过程、海洋模式的经向能量输送过程、以及海洋与大气的淡水通量耦合方案的改进方面。 相似文献
10.
利用CAM3.0气候模式模拟研究东亚地区气溶胶浓度增长以及1976/1977年前后发生的海温年代际变化对东亚夏季降水场的影响及其机制。采用四组试验:即对东亚区域(100~150 °E,20~50 °N)分别进行的单独加倍黑碳气溶胶浓度、单独加倍硫酸盐气溶胶浓度、同时加倍这两种气溶胶浓度的三组关于气溶胶直接气候效应的试验及全球海温在1976/1977前后发生变化的海温年代际变化试验,来比较、探讨海温年代际变化和东亚地区气溶胶浓度增加对东亚夏季降水的影响机制。结果表明,无论是海温年代际变化还是各种气溶胶的浓度加倍,都能导致我国出现长江以北地区降水减少-东南沿海地区降水增加的“南涝北旱”的降水异常分布型。但两者在洋面上空降水的迥异表现及东亚低层风场的不同变化,显示其具有不同的异常降水机制。比较三类气溶胶浓度增加的试验结果发现:在单独硫酸盐气溶胶浓度增加试验中,东亚中部出现最显著的中下层大气降温、异常下沉气流以及降水减少;而在黑碳气溶胶试验中,出现在东亚中部的异常下沉气流强度减弱且位置偏南;在同时增加两类气溶胶浓度时,降水异常分布与单独黑碳气溶胶浓度增加所导致的降水异常相近,但强度减小。 相似文献
11.
Relative contribution of soil moisture and snow mass to seasonal climate predictability: a pilot study 总被引：1，自引：1，他引：0
Hervé Douville 《Climate Dynamics》2010,34(6):797-818
Land surface hydrology (LSH) is a potential source of long-range atmospheric predictability that has received less attention
than sea surface temperature (SST). In this study, we carry out ensemble atmospheric simulations driven by observed or climatological
SST in which the LSH is either interactive or nudged towards a global monthly re-analysis. The main objective is to evaluate
the impact of soil moisture or snow mass anomalies on seasonal climate variability and predictability over the 1986–1995 period.
We first analyse the annual cycle of zonal mean potential (perfect model approach) and effective (simulated vs. observed climate)
predictability in order to identify the seasons and latitudes where land surface initialization is potentially relevant. Results
highlight the influence of soil moisture boundary conditions in the summer mid-latitudes and the role of snow boundary conditions
in the northern high latitudes. Then, we focus on the Eurasian continent and we contrast seasons with opposite land surface
anomalies. In addition to the nudged experiments, we conduct ensembles of seasonal hindcasts in which the relaxation is switched
off at the end of spring or winter in order to evaluate the impact of soil moisture or snow mass initialization. LSH appears
as an effective source of surface air temperature and precipitation predictability over Eurasia (as well as North America),
at least as important as SST in spring and summer. Cloud feedbacks and large-scale dynamics contribute to amplify the regional
temperature response, which is however, mainly found at the lowest model levels and only represents a small fraction of the
observed variability in the upper troposphere. 相似文献
12.
全球变暖形势下中国陆表水分的变化 总被引：1，自引：1，他引：0
利用政府间气候变化委员会第四次评估报告（IPCCAR4）中的10个耦合模式CO：加倍试验和控制试验的模拟结果,分析了全球变暖背景下中国水分的变化。结果表明,随着全球变暖,东亚夏季风增强,冬季风减弱,使得冬夏季向中国区域输送的水汽都增强;中国区域降水,夏季除长江流域外基本都增加,冬季除华南外都增加。夏季降水蒸发差（P—E）除了在东北和南方增加外,从长江流域一直到西北有一带状减小带;冬季几乎所有模式的P—E表现为北方增加、南方减小。在全球变暖背景下,降水、蒸发和径流的综合结果以及积雪的作用使得土壤湿度在干旱区增加,且冬季干旱区土壤变湿的强度和范围大于夏季,然而在其他区域土壤湿度减少。上述结论是基于多模式集合平均结果,对未来气候的预估具有一定的参考价值,然而模式间存在较强差异性,仍具有较大不确定性。 相似文献
13.
The relative influence of soil moisture and SST in climate predictability explored within ensembles of AMIP type experiments 总被引：4，自引：1，他引：4
Three ensembles of AMIP-type simulations using the Arpege-climat coupled land–atmosphere model have been designed to assess the relative influence of SST and soil moisture (SM) on climate variability and predictability. The study takes advantage of the GSWP2 land surface reanalysis covering the 1986–1995 period. The GSWP2 forcings have been used to derive a global SM climatology that is fully consistent with the model used in this study. One ensemble of ten simulations has been forced by climatological SST and the simulated SM is relaxed toward the GSWP2 reanalysis. Another ensemble has been forced by observed SST and SM is evolving freely. The last ensemble combines the observed SST forcing and the relaxation toward GSWP2. Two complementary aspects of the predictability have been explored, the potential predictability (analysis of variance) and the effective predictability (skill score). An analysis of variance has revealed the effects of the SST and SM boundary forcings on the variability and potential predictability of near-surface temperature, precipitation and surface evaporation. While in the tropics SST anomalies clearly maintain a potentially predictable variability throughout the annual cycle, in the mid-latitudes the SST forced variability is only dominant in winter and SM plays a leading role in summer. In a similar fashion, the annual cycle of the hindcast skill (evaluated as the anomalous correlation coefficient of the three ensemble means with respect to the “observations”) indicates that the SST forcing is the dominant contributor over the tropical continents and in the winter mid-latitudes but that SM is supporting a significant part of the skill in the summer mid-latitudes. Focusing on boreal summer, we have then investigated different aspects of the SM and SST contribution to climate variations in terms of spatial distribution and time-evolution. Our experiments suggest that SM is potentially an additional source of climate predictability. A realistic initialization of SM and a proper representation of the land–atmosphere feedbacks seem necessary to improve state-of-the-art dynamical seasonal predictions, but will be actually efficient only in the areas where SM anomalies are themselves predictable at the monthly to seasonal timescale (since remote effects of SM are probably much more limited than SST teleconnections). 相似文献
14.
Contrasting Impacts of South and North Tropical Indian Ocean Sea Surface Temperature Anomalies on East Asian Summer Climate 
下载免费PDF全文
下载免费PDF全文 《大气和海洋科学快报》2015,(6)
Using observational data and model simulations,the author find that the North Indian Ocean(NIO)sea surface temperature(SST)anomalies can trigger an eastward atmospheric Kelvin wave propagating into the equatorial western Pacific,inducing an anomalous anticyclone over the subtropical Northwest Pacific(NWP)and resulting in prominent summer climate anomalies in the East Asia-Northwest Pacific(EANWP)region.However,the response of tropospheric temperatures and atmospheric Kelvin waves to the South Indian Ocean(SIO)SST anomalies is weak;as a result,the impact of the SIO SST anomalies on the EANWP summer climate is weak.The contrasting impacts of NIO and SIO SST anomalies on the EANWP summer climate is possibly due to the different mean state of SSTs in the two regions.In summer,the climatological SSTs in the NIO are higher than in the SIO,leading to a stronger response of atmospheric convection to the NIO SST anomalies than to the SIO SST anomalies.Thus,compared with the SIO SST anomalies,the NIO SST anomalies can lead to stronger tropospheric air temperature anomalies and atmospheric Kelvin waves to affect the EANWP summer climate. 相似文献
15.
Predictability of Northwest Pacific climate during summer and the role of the tropical Indian Ocean 总被引：3，自引：2，他引：1
Jasti Sriranga Chowdary Shang-Ping Xie Jing-Jia Luo Jan Hafner Swadhin Behera Yukio Masumoto Toshio Yamagata 《Climate Dynamics》2011,36(3-4):607-621
A seasonal forecast system based on a global, fully coupled ocean?Catmosphere general circulation model is used to (1) evaluate the interannual predictability of the Northwest Pacific climate during June?CAugust following El Ni?o [JJA(1)], and (2) examine the contribution from the tropical Indian Ocean (TIO) variability. The model retrospective forecast for 1983?C2006 captures major modes of atmospheric variability over the Northwest Pacific during JJA(1), including a rise in sea level pressure (SLP), an anomalous anticyclone at the surface, and a reduction in subtropical rainfall, and increased rainfall to the northeast over East Asia. The anomaly correlation coefficient (ACC) for the leading principal components (PCs) of SLP and rainfall stays above 0.5 for lead time up to 3?C4?months. The predictability for zonal wind is slightly better. An additional experiment is performed by prescribing the SST climatology over the TIO. In this run, designated as NoTIO, the Northwest Pacific anticyclone during JJA(1) weakens considerably and reduces its westward extension. Without an interactive TIO, the ACC for PC prediction drops significantly. To diagnose the TIO effect on the circulation, the differences between the two runs (Control minus NoTIO) are analyzed. The diagnosis shows that El Nino causes the TIO SST to rise and to remain high until JJA(1). In response to the higher than usual SST, precipitation increases over the TIO and excites a warm atmospheric Kelvin wave, which propagates into the western Pacific along the equator. The decrease in equatorial SLP drives northeasterly wind anomalies, induces surface wind divergence, and suppresses convection over the subtropical Northwest Pacific. An anomalous anticyclone forms in the Northwest Pacific, and the intensified moisture transport on its northwest flank causes rainfall to increase over East Asia. In the NoTIO experiment, the Northwest Pacific anticyclone weakens but does not disappear. Other mechanisms for maintaining this anomalous circulation are discussed. 相似文献
16.
Impacts of the leading modes of tropical Indian Ocean sea surface temperature anomaly on sub-seasonal evolution of the circulation and rainfall over East Asia during boreal spring and summer 下载免费PDF全文
下载免费PDF全文 The two leading modes of the interannual variability of the tropical Indian Ocean (TIO) sea surface temperature (SST) anomaly are the Indian Ocean basin mode (IOBM) and the Indian Ocean dipole mode (IODM) from March to August. In this paper, the relationship between the TIO SST anomaly and the sub-seasonal evolution of the circulation and rainfall over East Asia during boreal spring and summer is investigated by using correlation analysis and composite analysis based on multi-source observation data from 1979 to 2013, together with numerical simulations from an atmospheric general circulation model. The results indicate that the impacts of the IOBM on the circulation and rainfall over East Asia vary remarkably from spring to summer. The anomalous anticyclone over the tropical Northwest Pacific induced by the warm IOBM is closely linked with the Pacific–Japan or East Asia–Pacific teleconnection pattern, which persists from March to August. In the upper troposphere over East Asia, the warm phase of the IOBM generates a significant anticyclonic response from March to May. In June and July, however, the circulation response is characterized by enhanced subtropical westerly flow. A distinct anomalous cyclone is found in August. Overall, the IOBM can exert significant influence on the western North Pacific subtropical high, the South Asian high, and the East Asian jet, which collectively modulate the precipitation anomaly over East Asia. In contrast, the effects of the IODM on the climate anomaly over East Asia are relatively weak in boreal spring and summer. Therefore, studying the impacts of the TIO SST anomaly on the climate anomaly in East Asia should take full account of the different sub-seasonal response during boreal spring and summer. 相似文献
17.
Using the CAM3.0 model, we investigated the respective effects of aerosol concentration increasing and decadal variation of global sea surface temperature(SST) around year 1976/77 on the East Asian precipitation in boreal summer. By doubling the concentration of the sulfate aerosol and black carbon aerosol separately and synchronously in East Asia(100-150 °E, 20-50 °N), the climate effects of these aerosols are specifically investigated. The results show that both the decadal SST changing and aerosol concentration increasing could lead to rainfall decreasing in the center of East Asia, but increasing in the regions along southeast coast areas of China. However, the different patterns of rainfall over ocean and lower wind field over Asian continent between aerosol experiments and SST experiments in CAM3.0 indicate the presence of different mechanisms. In the increased aerosol concentration experiments, scattering effect is the main climate effect for both sulfate and black carbon aerosols in the Eastern Asian summer. Especially in the increased sulfate aerosol concentration experiment, the climate scattering effect of aerosol leads to the most significant temperature decreasing, sinking convection anomalies and decreased rainfall in the troposphere over the central part of East Asia. However, in an increased black carbon aerosol concentration experiment, weakened sinking convection anomalies exist at the southerly position. This weakened sinking and its compensating rising convection anomalies in the south lead to the heavy rainfall over southeast coast areas of China. When concentrations of both sulfate and black carbon aerosols increase synchronously, the anomalous rainfall distribution is somewhat like that in the increased black carbon concentration aerosol experiment but with less intensity. 相似文献
18.
1998年和2016年北大西洋海温异常对中国夏季降水影响的数值模拟研究 总被引：3，自引：0，他引：3
基于1979-2016年ERA-Interim再分析资料和CAM5.3模式,研究了2016年和1998年北大西洋海温异常对中国夏季降水以及大尺度环流的可能影响及其机制。结果表明,这两年前夏（6-7月）长江中下游及其以南地区降水均异常偏多,但1998年降水异常较2016年更为显著。后夏（8月）,2016年长江以南地区降水异常偏多,长江-黄河流域降水异常偏少,而1998年降水异常分布与之相反。2016年和1998年夏季中国东部降水异常的差异与西北太平洋对流层低层异常反气旋以及欧亚中高纬度环流变化的共同作用直接相关。敏感性数值试验的结果表明,北大西洋海温异常的显著差异是导致2016年和1998年夏季中国东部降水以及大尺度环流异常存在明显差异的重要原因之一。一方面,北大西洋海温异常可以通过改变欧亚中高纬度环流进而对中国夏季降水产生影响。1998年北大西洋海温异常自热带至副极地呈类似"+ - +"型分布,这种海温异常型能够在前夏欧亚中高纬度地区激发出双阻型的环流异常响应。2016年北大西洋海温异常自热带至副极地呈相对弱的"- + -"型分布,欧亚中高纬度环流异常响应总体偏弱。另一方面,北大西洋海温异常还可以通过影响热带纬向环流进而对西北太平洋对流层低层异常反气旋起调制作用。1998年北大西洋海温异常对夏季西北太平洋异常反气旋起增强作用,这与热带印度洋-太平洋海温的强迫作用相协调。然而,2016年北大西洋海温异常则有利于西北太平洋异常反气旋的减弱,这与热带印度洋-太平洋海温的强迫作用相反。因此,在这3个大洋的协同作用下,2016年和1998年前夏西北太平洋异常反气旋均偏强,但前者的振幅弱于后者。在后夏,1998年西北太平洋对流层低层仍受异常反气旋控制,2016年则为异常气旋控制。 相似文献
19.
Influence of SST biases on future climate change projections 总被引：1，自引：0，他引：1
We use a quantile-based bias correction technique and a multi-member ensemble of the atmospheric component of NCAR CCSM3 (CAM3) simulations to investigate the influence of sea surface temperature (SST) biases on future climate change projections. The simulations, which cover 1977?C1999 in the historical period and 2077?C2099 in the future (A1B) period, use the CCSM3-generated SSTs as prescribed boundary conditions. Bias correction is applied to the monthly time-series of SSTs so that the simulated changes in SST mean and variability are preserved. Our comparison of CAM3 simulations with and without SST correction shows that the SST biases affect the precipitation distribution in CAM3 over many regions by introducing errors in atmospheric moisture content and upper-level (lower-level) divergence (convergence). Also, bias correction leads to significantly different precipitation and surface temperature changes over many oceanic and terrestrial regions (predominantly in the tropics) in response to the future anthropogenic increases in greenhouse forcing. The differences in the precipitation response from SST bias correction occur both in the mean and the percent change, and are independent of the ocean?Catmosphere coupling. Many of these differences are comparable to or larger than the spread of future precipitation changes across the CMIP3 ensemble. Such biases can affect the simulated terrestrial feedbacks and thermohaline circulations in coupled climate model integrations through changes in the hydrological cycle and ocean salinity. Moreover, biases in CCSM3-generated SSTs are generally similar to the biases in CMIP3 ensemble mean SSTs, suggesting that other GCMs may display a similar sensitivity of projected climate change to SST errors. These results help to quantify the influence of climate model biases on the simulated climate change, and therefore should inform the effort to further develop approaches for reliable climate change projection. 相似文献