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1.
当代气候研究计划   总被引:1,自引:0,他引:1  
就气候系统问题,国际上与气候及其变化有关的重要科学计划、尤其是气候变化及可预报性研究(CLIVAR)计划,作了简要介绍,同时还就气候预测问题作了讨论。  相似文献   

2.
Reanalyses, based on numerical weather prediction methods assimilating past observations, provide continuous precipitation datasets and represent interesting options for assessing the climatology of regions with sparse station networks (e.g., northern Canada). However, reanalysis series cannot be used directly because of possible biases and mismatch between their spatial and temporal resolutions with that needed for local applications. To address these issues, a Stochastic Model Output Statistics (SMOS) approach was selected to post-process precipitation series simulated by the Climate Forecast System Reanalysis (CFSR) across Canada. This approach uses CFSR precipitation as a covariate and is based on two regression models: the first one is a logistic regression that deals with precipitation occurrence, and the second is a vector generalized linear model for precipitation intensity. At-site post-processed daily precipitation series are randomly generated using the SMOS approach, and selected climate indicators from the Expert Team on Climate Change Detection and Indices, which is jointly sponsored by the Commission for Climatology of the World Meteorological Organization's (WMO) World Climate Data and Monitoring Programme, the Climate Variability and Predictability Programme of the World Climate Research Programme, and the Joint WMO-IOC Technical Commission for Oceanography and Marine Meteorology (CCI/CLIVAR/JCOMM) are estimated and compared with corresponding observed and CFSR values. The two models in the SMOS approach, in addition to adequately correcting systematic biases, produced better predictions than the climatology of the wet and dry and intensity sequences. Additionally, the SMOS generally yields consistent climate indices when compared with those from CFSR without post-processing, though there is still room for improvement for specific indices (e.g., annual maximum of cumulative wet days).  相似文献   

3.
A Review of Decadal/Interdecadal Climate Variation Studies in China   总被引:22,自引:4,他引:18  
Decadal/interdecadal climate variability is an important element in the CLIVAR (Climate Variability and Predictability) and has received much attention in the world. Many studies in relation to interdecadal variation have also been completed by Chinese scientists in recent years. In this paper, an introduction in outline for interdecadal climate variation research in China is presented. The content includes the features of interdecadal climate variability in China, global warming and interdecadal temperature variability,the NAO (the North Atlantic Oscillation)/NPO (the North Pacific Oscillation) and interdecadal climate variation in China, the interdecadal variation of the East Asian monsoon, the interdecadal mode of SSTA(Sea Surface Temperature Anomaly) in the North Pacific and its climate impact, and abrupt change feature of the climate.  相似文献   

4.
A review of ocean-atmosphere interaction studies in China   总被引:2,自引:0,他引:2  
A large number of papers have been published and great efforts have been made in the recent 20 years by the Chinese oceanographic and meteorological scientists in the ocean-atmosphere interaction studies. The present paper is an overview of the major achievements made by Chinese scientists aad their collaborators in studies of larger scale ocean-atmosphere interaction in the following oceans: the South China Sea, the Tropical Pacific, the indian Ocean and the North Pacific. Many interesting phenomena and dynamic mechanisms have been discovered and studied in these papers. These achievements have improved our understanding of climate variability and have great implications in climate prediction, and thus are highly relevant to the ongoing international Climate Variability and Predictability (CLIVAR) efforts.  相似文献   

5.
The ability of atmospheric general circulation models (AGCMs), that are forced with observed sea surface temperatures (SSTs), to simulate the Indian monsoon rainfall (IMR) variability on interannual to decadal timescales is analyzed in a multimodel intercomparison. The multimodel ensemble has been performed within the CLIVAR International “Climate of the 20th Century” (C20C) Project. This paper is part of a C20C intercomparison of key climate time series. Whereas on the interannual timescale there is modest skill in reproducing the observed IMR variability, on decadal timescale the skill is much larger. It is shown that the decadal IMR variability is largely forced, most likely by tropical sea surface temperatures (SSTs), but as well by extratropical and especially Atlantic Multidecadal Oscillation (AMO) related SSTs. In particular there has been a decrease from the late 1950s to the 1990s that corresponds to a general warming of tropical SSTs. Using a selection of control integrations from the World Climate Research Programme’s (WCRP’s) Coupled Model Intercomparison Project phase 3 (CMIP3), it is shown that the increase of greenhouse gases (GHG) in the twentieth century has not significantly contributed to the observed decadal IMR variability.  相似文献   

6.
《Atmospheric Research》2010,95(4):616-628
The objective of this study is to find out the spatial and temporal variability of the dry and wet spells in Greece, during the period 1958–2007. The meteorological data with respect to daily precipitation totals were acquired from 27 meteorological stations of the Hellenic National Meteorological Service, which are uniformly distributed over the country. The dry spells concern consecutive dry days (CDD); the largest number of consecutive days with daily precipitation amount less than 1 mm, within a year. The wet spells concern consecutive wet days (CWD); the largest number of consecutive days with daily precipitation amount more than or equal to 1 mm, within a year, as defined by the Expert Team on Climate Change Detection and Indices (ETCCDI), jointly sponsored by the Commission for Climatology (CCl) of the World Meteorological Organization's (WMO) World Climate Data and Monitoring Programme (WCDMP), the Climate Variability and Predictability (CLIVAR) Programme of the World Climate Research Programme (WCRP) and the Joint WMO-IOC Technical Commission for Oceanography and Marine Meteorology (JCOMM).As results from the analysis, the spatial distributions of the mean annual CDD and the mean annual CWD along with their trends, within the examined period, are presented. The findings indicate that CDD obtain maxima in the Cyclades Islands and the southeastern Aegean Sea, while minima are found in the northwestern Greece. On the contrary, the longest CWD are observed in western Greece and western part of Crete Island and the shortest in the eastern continental Greece and in the majority of the Aegean Sea. On an annual basis, the temporal variability of CWD shows statistically significant (confidence level of 95%) negative trends, mainly in the western region of Greece, while insignificant positive trends for CDD appear almost all over the country with emphasis in the southeastern region. Finally, in order to interpret the drier and wetter periods within the examined period, the 850 hPa and the 500 hPa geopotential height (m) composites of the anomalies from 1958–1996 climatological normal (clino), are analysed using the National Centers for Environmental Prediction (NCEP) reanalysis data.  相似文献   

7.
The seasonal mean variability of the atmospheric circulation is affected by processes with time scales from less than seasonal to interannual or longer. Using monthly mean data from an ensemble of Atmospheric General Circulation Model (AGCM) realisations, the interannual variability of the seasonal mean is separated into intraseasonal, and slowly varying components. For the first time, using a recently developed method, the slowly varying component in multiple AGCM ensembles is further separated into internal and externally forced components. This is done for Southern Hemisphere 500?hPa geopotential height from five AGCMs in the CLIVAR International Climate of the Twentieth Century project for the summer and winter seasons. In both seasons, the intraseasonal and slow modes of variability are qualitatively well reproduced by the models when compared with reanalysis data, with a relative metric finding little overall difference between the models. The Southern Annular Mode (SAM) is by far the dominant mode of slowly varying internal atmospheric variability. Two slow-external modes of variability are related to El Ni?o-Southern Oscillation (ENSO) variability, and a third is the atmospheric response to trends in external forcing. An ENSO-SAM relationship is found in the model slow modes of variability, similar to that found by earlier studies using reanalysis data. There is a greater spread in the representation of model slow-external modes in winter than summer, particularly in the atmospheric response to external forcing trends. This may be attributable to weaker external forcing constraints on SH atmospheric circulation in winter.  相似文献   

8.
PAGES计划与CLIVAR计划中的交叉科学问题   总被引:5,自引:1,他引:5  
王绍武 《气象学报》1997,55(6):662-669
过去全球变化(PAGES)是国际地圈、生物圈计划(IGBP)的一个核心计划,从1991年开始预计施行到2010年。气候变率与可预报性研究(CLIVAR)是世界气候研究计划(WCRP)新设的一个子计划,从1996年开始也是施行到2010年。两个计划有不少交叉的科学问题:(1)低纬气候变化动力学,(2)全球海洋温盐环流,(3)区域到全球尺度水的变率,(4)气候突变动力学,(5)气候模式发展及改进,(6)气候变化的检测,本文对以上问题作了扼要介绍。  相似文献   

9.
Extreme climate index is one of the useful tools to monitor and detect climate change. The primary objective of this study is to provide a more comprehensively the changes in extreme precipitation between the periods of 1954–1983 and 1984–2013 in Shaanxi province under climate change, which will hopefully provide a scientific understanding of the precipitation-related natural hazards such as flood and drought. Daily precipitation from 34 surface meteorological stations were used to calculated 13 extreme precipitation indices (EPIs) generated by the joint World Meteorological Organization Commission for Climatology (CCI)/World Climate Research Programme (WCRP) project on Climate Variability and Predictability (CLIVAR) expect Team on climate change Detection, Monitoring and Indices (ETCCDMI). Two periods including 1954–1983 and 1984–2013 were selected and five types of precipitation days (R10mm-R100mm) were defined, to provide more evidences of climate change impacts on the extreme precipitation events, and specially, to investigate the changes in different types of precipitation days. The EPIs were generated using RClimRex software, and the trends were analyzed using Mann-Kendall nonparametric test and Sen’s slope estimator. The relationships between the EPIs and the impacts of climate anomalies on typical EPIs were investigated using correlation and composite analysis. The mainly results include: 1) Thirteen EPIs, except consecutive dry day (CDD), were positive trends dominated for the period of 1984–2013, but the trends were not obvious for the period of 1954–1983. Most of the trends were not statistically significant at 5 % significance level. 2) The spatial distributions of stations that exhibited positive and negative trends were scattered. However, the stations that had negative trends mainly distributed in the north of Shaanxi province, and the stations that had positive trends mainly located in the south. 3) The percentage of stations that had positive trends had increased from the period of 1954–1983 to 1984–2013 for all the 13 EPIs except CDD, indicating the possible climate change impacts on extreme precipitation events. 4) The correlations between annual total wet-day precipitation (PRCPTOT) and other 12 EPIs varied for different indices and stations. The composite analysis found that El Niño Southern Oscillation (ENSO) exerted greater impacts on PRCPTOT than other EPIs and greater in the Guanzhong Plain (GZP) than Qinling-Dabashan Mountains (QDM) and Shanbei Plateau (SBP) of Shaanxi province.  相似文献   

10.
国外关于年代际气候变率的研究   总被引:28,自引:2,他引:26  
王绍武  朱锦红 《气象学报》1999,57(3):376-384
文中指出在气候变率与可预报性研究计划中,列出年代际气候变率及可预报性研究子计划充分显示出这个问题的重要性,回顾并总结了近年来年代际气候变率的研究成果,特别对全球气候变暖、海气相互作用、温盐环流、自然气候变率和ENSO的年代际变率的研究几个重点问题进行了讨论,最后对年代际气候变率研究今后的发展方向提出了看法。  相似文献   

11.
华北中部近45a极端降水事件变化特征   总被引:9,自引:1,他引:8  
利用华北中部41个气象台站1961—2005年逐日降水资料,采用通用的极端气候指数,分析了近45a来华北中部极端降水事件频率变化的时空特征。结果表明:华北中部平均年最大日降水量呈下降趋势,南部平原地区一般减少,北部山地区域多有增加,降水日数有较明显减少,强降水日数和暴雨日数变化趋势不明显,降水日数的减少主要是中、小雨(雪)日数减少造成的。暴雨日数和强度在20世纪90年代中后期显著增加。华北中部强降水日数和暴雨日数在降水日数中的比重有增大趋势,强降水量和暴雨降水量在总降水量中的比重可能也增加了。这种相对增加趋势主要发生在20世纪90年代中期以后。  相似文献   

12.
近45年来河北省极端降水事件的变化研究   总被引:7,自引:1,他引:6  
高霞  王宏  于成文  戴新刚  史丽红 《气象》2009,35(7):10-15
利用河北省1961-2005年逐日降水资料,采用通用的极端气候指数,分析了近45年河北省极端降水事件频率变化的时空特征.结果表明,全省平均年最大日降水量呈下降趋势,1980年为由多向少的转折点;强降水日数和暴雨日数变化不大,但南部平原地区一般减少,北部山地区域多有增加,暴雨日数和强度在1990年代中后期显著增加;降水日数有较明显减少,南部和东南部平原减少更显著;降水日数的减少主要是中、小雨(雪)日数减少造成的.这些结果说明,河北省强降水日数和暴雨日数在降水日数中的比重有增大趋势,强降水量和暴雨降水量在总降水量中的比重可能增加了.这种相对增加趋势主要发生在1990年代中期以后.  相似文献   

13.
对2010年1-12月和春季(3-5月)、夏季(6-8月)国家气候中心和内蒙古气候中心的短期气候预测业务质量进行评分,以检验国家级和自治区级气候预测业务对内蒙古的预测能力.通过对比分析表明:总体来看,2010年短期气候预测质量检验评分内蒙古气候中心91.7%的月份温度预测和75%的月份降水预测高于国家气候中心,其中,春季温度预测较差;夏季降水预测较差.平均而言,业务预测质量明显高于模式产品质量.因此,需要在内蒙古业务预测分析参考时注意,降水预测的指导能力相对较弱.  相似文献   

14.
15.
关于亚洲季风与ENSO循环相互作用研究最近的进展   总被引:32,自引:11,他引:21  
综述和回顾了最近6年我国在实施国际气候变化与可预测性研究计划(CLIVAR)中在季风与ENSO循环相互作用方面的研究成果.特别是回顾了ENSO循环对东亚和我国降水、水汽输送、季风环流、西太平洋副热带高压的影响,以及亚洲季风对ENSO循环的动力作用和ENSO循环的物理机制等的研究成果,并且,还回顾了关于季风与ENSO循环相互作用的数值模拟和可预测性的研究成果.同时指出今后在此领域急待研究的一些问题.  相似文献   

16.
年代际气候变化研究   总被引:65,自引:17,他引:48  
概括的介绍了中国科学家近几年在年代际气候变化方面的研究进展,包括中国气候的年代际变化特征,北大西洋涛动(NAO)和北太平洋涛动(NPO)与中国年代际气候变化的关系,北太平洋海面温度(SST)年代际模及其影响,大气环流系统的年代际变化以及气候突变问题.  相似文献   

17.
Climate Dynamics - The present study explored the performance of the current coupled models obtained from the Asia Pacific Economic Cooperation (APEC) Climate Centre (APCC) in representing the...  相似文献   

18.
文章引进了美国NCAR的区域气候模式,并对该模式进行了改造和改进,建立了能适合中国区域性气候特征,模拟中国区域性气候的模式。在此基础上运用该模式对1991年夏季长江流域强降水过程进行了模拟计算,结果表明,该模式具有模拟长江流域强降水过程的能力。  相似文献   

19.
气候变化是当前世界面临的巨大挑战,应对气候变化需要国际间合作已成为普遍共识。IPCC第六次评估报告(AR6)第三工作组(WGⅢ)报告第十四章回顾了IPCC第五次评估报告(AR5)以来气候变化国际合作的进展,基于所提出的评价体系对进展进行了系统评估。报告认为,AR5以来气候变化国际合作最重要的进展是基于《巴黎协定》建立的以国家自主贡献为核心的全球行动模式;除《巴黎协定》外,国际上也形成了多种形式的合作机制,其中,气候俱乐部是国际气候合作研究的新热点。对于《巴黎协定》的有效性,目前国际社会存在正反两种观点,并认为《巴黎协定》能否达成既定目标取决于是否有能力强化全球下一步的集体气候行动目标和实施。  相似文献   

20.

Potential changes in future climate in the Texas Plains region were investigated in the context of agriculture by analyzing three climate model projections under the A2 climate scenario (medium–high emission scenario). Spatially downscaled historic (1971–2000) and future (2041–2070) climate datasets (rainfall and temperature) were downloaded from the North American Regional Climate Change Assessment Program (NARCCAP). Climate variables predicted by three regional climate models (RCMs) namely the Regional Climate Model Version3–Geophysical Fluid Dynamics Laboratory (RCM3-GFDL), Regional Climate Model Version3–Third Generation Coupled Global Climate Model (RCM3-CGCM3), and Canadian Regional Climate Model–Community Climate System Model (CRCM-CCSM) were evaluated in this study. Gaussian and Gamma distribution mapping techniques were employed to remove the bias in temperature and rainfall data, respectively. Both the minimum and maximum temperatures across the study region in the future showed an upward trend, with the temperatures increasing in the range of 1.9 to 2.9 °C and 2.0 to 3.2 °C, respectively. All three climate models predicted a decline in rainfall within a range of 30 to 127 mm in majority of counties across the study region. In addition, they predicted an increase in the intensity of extreme rainfall events in the future. The frost-free season as predicted by the three models showed an increase by 2.6–3.4 weeks across the region, and the number of frost days declined by 17.9 to 30 %. Overall, these projections indicate considerable changes to the climate in the Texas Plains region in the future, and these changes could potentially impact agriculture in this region.

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