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1.
以我国大陆2416个气象观测站点组成的站网为参考,以观测序列的相关性表示对气候变化信号的监测能力,分析不同地区单位经纬度网格内站点数对信号监测能力的影响,得到特定监测能力要求下所需的站点数,为大尺度气候观测站网的站点设置提供科学依据。对2.5°×2.5°网格来说,当要求子集站网气温序列与标准站网气温序列相关系数超过0.99和0.95时,所需的站点数分别为750和377;当要求子集站网降水量序列与标准站网降水量序列的相关系数超过0.95和0.90时,需要的站点数分别为670和417。对2.5°×3.5°和5.0°×5.0°经纬度网格的分析发现,对站点数量要求较高的区域大部分是地形过渡区,一般来说,降水量观测对站点密度的要求高于气温。  相似文献   

2.
吴薇  黄晓龙  周春花  郭旭  杜冰  王婷 《气象科技》2023,51(5):639-647
气象台站站网布局质量直接影响观测资料的使用效益。通过水平站间距、垂直层分布、坡度、流域、风险区划、站点控制范围以及网格覆盖率等多个角度对四川省现有地面雨量站站网进行分析,以期为后续增减站点、站网布局优化提供科学依据。分析结果表明:①四川省雨量站平均水平站间距为9.04 km,完全满足世界气象组织OSCAR对气候监测领域的需求,满足全球数值天气预报的“突破”需求,但距理想的“目标”还有一定差距;②四川省80%以上的雨量站布设在低海拔和中海拔区域,92.38%的雨量站布设在平坡地、较平坡地、缓坡地和较缓坡地;③四川省较高和高风险区面积占比不足40%,站数占比达50%以上,且站网密度随着风险区从低到高逐渐增大;④站点控制面积<100 km2的区域主要分布在四川盆地内,川西高原站点控制面积普遍在100 km2以上,个别站点控制面积在1000 km2以上;⑤不同分辨率网格覆盖率,四川盆地内最高,攀西地区次之,川西高原相对较低。  相似文献   

3.
胡晓明  王国复  黄菲 《气象科技》2014,42(3):382-390
利用1961—2011年51年的日降水资料,以2400多站组成的国家级站网为基准,通过分析不同站网对中雨日数、大雨日数、强降水量和极强降水量4种极端降水指数监测差异,对中国不同地面观测站网对中国极端降水事件的代表性进行了评估。研究发现,各站网对极端降水事件变化的时间和空间分布监测精度由高到低依次为:基本基准站网,基本站网,基准站网,GCOS站网。GCOS站网和基准站网对各降水指数的空间分布的影响与标准站网相差较大。基本基准站网和基本站网对各极端降水指数变化方向及变化速率的空间分布与标准站网非常一致,但在西南地区北部、东北中东部地区、长江中游北侧局部地区的观测精度仍然不理想。  相似文献   

4.
中国气候资料站网均匀化订正的一种方案及应用   总被引:2,自引:0,他引:2  
定义了中国160站站网不均匀性的两个度量参数—站域面积和站网密度。在给定球冠区面积S0=50×104km2下求得了它们的值,并论证了其合理性。用它们构造了第一类权重函数,将该权重函数应用于中国160站站网1、4、7、10月气温的全国气候平均值及均方差值的计算,得到了合理的结果。同时,构造了第二类权重函数,并应用于气温距平场时间序列的订正,对订正前、后的距平场序列进行EOF(empiricalorthogonalfunctions)分析,论证了订正后的结果优于订正前。  相似文献   

5.
站网均匀化订正对中国夏季气温EOF分析的改进   总被引:1,自引:0,他引:1  
本文对中国160站站网上1960~2010年夏季(6~8月)气温距平场序列进行了站网均匀化订正,对订正前、后的气温距平场序列作了EOF分析.结果表明:(1)订正后的前3个典型场高绝对值区均衡分布在三北(东北、华北、西北)地区、青藏高原和长江中下游地区,与夏季气温均方差场高值区位置基本一致;订正前的前3个特征向量高绝对值...  相似文献   

6.
本文统计分析了亚洲地区(60—140°E,30—60°N)500mb 8个区域的纬向环流指数与我国东部地区气温、降水量的关系,指出500mb区域纬向环流指数与我国东部地区各气候带的温度和降水量均有较好的对应关系。可以用500mb关键区的纬向环流指数作为我国东部地区各气候带温度、降水量气候预报的参考指标。  相似文献   

7.
气候观测环境代表性和观测资料质量是开展大尺度气候变化监测和研究的前提。为了解我国干燥区气象观测环境变化和台站代表性,作者对河西走廊和北疆九个国家级气象站观测环境开展了调研。本文介绍了调研了解到的情况,并结合先前研究结果,从气候变化监测和研究的视角,讨论了西北干燥区地面观测站代表性问题。目前我国西北地区气象站地面观测,对于干燥区的城市和绿洲区域气候及其变化,具有较高的代表性,但对更广大的荒漠和半荒漠背景气候及其变化,代表性仍显不足。作者发现,早先研究中指出的北疆等地区城镇站地面气温序列负向城市化影响,应与观测场周围局地甚至区域尺度绿洲扩大有直接联系,较难反映绿洲以外干燥区地带性气温变化。针对地面观测环境调研所发现的问题,文章最后提出了几点建议,希望对未来国家基准气候站网设计和建设提供一定参考。  相似文献   

8.
中国地基GPS气象应用站网建设展望   总被引:2,自引:1,他引:2  
曹云昌  方宗义  夏青  赵志强 《气象》2006,32(11):42-47
地基GPS探测大气具有探测精度高、时间分辨率高、不需要标定、设备可综合利用等诸多优点,随着中国GPS地面基准站网的建设,在将来的基准站网的气象应用方面,可分为两个层次:覆盖全国的、站间距离约100km的国家级GPS大气探测网,主要监测天气尺度的水汽分布和变化,以及电离层电子密度分布;在一些经济发达的地区,建立站间距约10-40km的中尺度GPS大气探测网,主要任务是监测中尺度水汽场及变化,并利用层析技术获取中尺度水汽廓线。在将来的站网建设时,将主要把国家、地方各部门的基准站网和气象部门的站网相结合,来满足气象部门的业务需要。气象部门的建设,将依赖于中国气象局的业务技术体制,特别是通讯和业务运行体制,面向应用,以期利用该项技术提高气象预报的精度和时效,进行空间天气的监测和气候的监测预测。  相似文献   

9.
采用站网均匀化订正方法处理了中国160站站网1951—2010年冬季(12月-次年2月)气温距平序列,订正后的序列较好地处理了由站网不均匀性引起的方差不均匀。对订正前、后序列分别作了EOF分析,结果表明:1)订正后序列的前2个典型场上的高绝对值区比订正前序列的前2个特征向量有更好的组织性,其高值区主要位于三北地区(西北、华北、东北)及青藏高原,与均方差场的高值区基本一致;2)订正前、后主要模态时间系数演变特征相似(rh≥0.886,h=^-1,2),但订正后的前2个时间系数的线性分量和年代际变化分量对它们的方差贡献更加集中于第一模态;3)订正后资料EOF分析的第一个典型场和时间系数中的线性分量可以给出中国最近60a冬季主要强增暖区的分布;其年代际分量与分析期间中国强年代际变化分布区域的一致性也优于订正前资料的EOF分析结果。  相似文献   

10.
熊秋芬  黄玫  熊敏诠  胡江林 《高原气象》2011,30(6):1615-1625
利用2006-2008年2 403个国家气象观测站地面雨量计的逐日降水量资料,采用与网格点最近的观测站有、无降水确定该网格点有、无降水和Barnes插值方案确定网格点降水大小的混合插值方案,得到全国空间分辨率为0.1°×0.1°(约10km×10km)的逐日降水量格点数据,在此基础上通过交叉检验方法统计格点数据的误差,...  相似文献   

11.
Four precipitation observational networks with varied station densities are maintained in China. They are: the Global Climate Observation System (GCOS) Surface Network (GSN), the national Reference Climate Network (RCN), the national Basic Meteorological Network (BMN), and the national Ordinary Meteorological Network (OMN). The GSN, RCN, BMN, and the merged network of RCN and BMN (R&B) have been widely used in climatology and climate change studies. In this paper, the impact of the usage of different networks on the precipitation climatology of China is evaluated by using the merged dataset of All Station Network (ASN) as a benchmark. The results show that all networks can capture the main features of the country average precipitation and its changing trends. The differences of average annual precipitation of the various networks from that of the ASN are less than 50 mm ( 10%). All networks can successfully detect the rising trend of the average annual precipitation during 1961-2009, with the R&B exhibiting the best representativeness (only 2.90% relative difference) and the GSN the poorest (39.77%). As to the change trends of country average monthly precipitation, the networks can be ranked in descending order as R&B (1.27%), RCN (2.35%), BMN (4.17%), and GSN (7.46%), and larger relative differences appear from August to November. The networks produce quite consistent spatial patterns of annual precipitation change trends, and all show an increasing trend of precipitation in Northwest and Southeast China, and a decreasing trend in North China, Northeast China, and parts of central China. However, the representativeness of the BMN and R&B are better in annual and seasonal precipitation trends, in spite of the fact that they are still far from satisfactory. The relative differences of trends in some months and regions even reach more than 50%. The results also show that the representativeness of the RCN for country average precipitation is higher than that of the BMN because the RCN has a more homogeneous distribution of stations.  相似文献   

12.
BCC气候模式对中国近50a极端气候事件的模拟评估   总被引:4,自引:1,他引:3  
利用中国区域437站1958—2005年逐日气温和降水资料,评估了国家气候中心(BeijingCli-mateCenter,BCC)气候模式对中国近50a极端气候事件空间分布、时间演变等方面的模拟能力。结果表明:1)模式对极端温度和降水多年平均的空间分布具有一定的模拟能力,但尚存在系统性的偏差。暖昼日数的模拟优于冷夜日数,全年冷夜日数的模拟优于冬季和夏季的模拟,而全年和夏季暖昼日数的模拟优于冬季的模拟。极端降水频次的模拟优于极端降水量的模拟;夏季和全年的模拟优于冬季的模拟。夏季极端降水频次的模拟较好,但冬季的模拟在长江中下游和华南偏小、北方偏大,而全年的模拟在长江下游及南部沿海地区系统性偏大;夏季和全年极端降水量的模拟系统性偏低,而冬季在北方偏高、南方偏低。2)模式较好地模拟出了夏季和全年冷夜日数的全国较为一致的减少趋势,再现东北和东南沿海地区冬季冷夜日数的减少趋势,但模拟的趋势较实测偏弱。模式对暖昼日数长期趋势的模拟效果较理想,较好地反映出了大部分地区暖昼事件发生频率显著增加的特征,但冬季的模拟尚有待改进。模式较好地模拟出了夏季和全年极端降水频次的长期趋势,较好地刻画了极端降水频次"南增北减"的特征;模式对冬季极端降水频次的变化趋势几乎无模拟能力。同样,模式也较好地模拟出了极端降水量夏季南增北减的分布形势和冬季的总体增加趋势,但对全年的模拟不理想。3)模式能较好地模拟出冷夜日数和暖昼日数异常变化的主要空间型,对EOF第一模态的时间演变特征具有一定模拟能力;但模式对第二模态时间演变特征的刻画能力较差。模式对极端降水指标的年际变化具有一定的模拟能力,对部分区域极端降水事件的年际变化具有较好的模拟能力;但模拟能力表现出了明显的区域性差异,部分区域极端降水年际变化的模拟结果与实况甚至相反,模式对极端降水年际变化的模拟能力还有待提高。所得结果可为BCC气候模式的改进及极端气候模拟、预估提供一定的参考。  相似文献   

13.
我国降水和气温的分级概率时空分布特征   总被引:1,自引:0,他引:1       下载免费PDF全文
采用全国160站1951—2009年月降水和气温资料,分析了短期气候预测业务评分办法中六级要素概率时空分布特征,并以1月、7月为代表获得了不同地区、不同级别降水和气温异常发生频率。结果表明:降水和气温的六级异常分布存在显著空间不均匀性和年代际变化特征,1980—2009年,北方降水在1月出现特少、特多等级和7月出现特少、偏少等级的概率较大,南方降水出现6个等级的概率基本相同;全国气温在1月和7月出现正常略低、正常略高和偏高等级的概率较大。1980—2009年与1951—1979年相比,全国1月降水为特多、偏多等级和7月降水为偏少等级的站数明显增加,全国1月气温为正常略高、偏高和特高等级的站数明显增加,呈明显的年代际变化特征。  相似文献   

14.
金秀良  宋燕  吴洪  张志良  尤莉 《气象科技》2014,42(6):1028-1038
在普查影响中国降水量和气温的大气环流系统及其指数的基础上,选取高相关、独立性强的大气环流系统指数作为预测因子,采用过滤式的筛选因子方法,动态建立线性回归方法,构建区域月气候预测模型(Regional Monthly Climate Forecast Model,RMCFM),自主开发操作系统,设置人机交互界面,实现人机交流操作方式,并通过解释应用方法做出中国160个台站的月降水量和月气温预测。实践证明,RMCFM具备天气气候专家系统概念,具有运算速度快,结构清晰易操作等特点,预测准确率较高,应用RMCFM可提高区域气候预测能力。  相似文献   

15.
建立一体化观测系统是中国气象事业发展战略确定的重要目标之一。本文站在西北区域气象事业发展的高度上,在充分分析西北地区天气气候和环境特征以及气候观测系统现状的前提下,对干旱气候观测系统(ACOS)进行了初步设计。系统由地基观测、空基探测、天基监测和信息传输与共享系统4部分构成,其中地基观测站网分为气象站(代表站)、生态气候试验站(重点站)和陆面过程综合试验基地(关键站)3个层次。干旱气候观测系统(ACOS)的建成将实现对西北地区内大气圈、水圈、冰冻圈、岩石圈和生物圈等5大圈层以及各圈层之间相互作用三维综合的观测。  相似文献   

16.
Climate changes over China from the present (1990–1999) to future (2046–2055) under the A1FI (fossil fuel intensive) and A1B (balanced) emission scenarios are projected using the Regional Climate Model version 3 (RegCM3) nests with the National Center for Atmospheric Research (NCAR) Community Climate System Model (CCSM). For the present climate, RegCM3 downscaling corrects several major deficiencies in the driving CCSM, especially the wet and cold biases over the Sichuan Basin. As compared with CCSM, RegCM3 produces systematic higher spatial pattern correlation coefficients with observations for precipitation and surface air temperature except during winter. The projected future precipitation changes differ largely between CCSM and RegCM3, with strong regional and seasonal dependence. The RegCM3 downscaling produces larger regional precipitation trends (both decreases and increases) than the driving CCSM. Contrast to substantial trend differences projected by CCSM, RegCM3 produces similar precipitation spatial patterns under different scenarios except autumn. Surface air temperature is projected to consistently increase by both CCSM and RegCM3, with greater warming under A1FI than A1B. The result demonstrates that different scenarios can induce large uncertainties even with the same RCM-GCM nesting system. Largest temperature increases are projected in the Tibetan Plateau during winter and high-latitude areas in the northern China during summer under both scenarios. This indicates that high elevation and northern regions are more vulnerable to climate change. Notable discrepancies for precipitation and surface air temperature simulated by RegCM3 with the driving conditions of CCSM versus the model for interdisciplinary research on climate under the same A1B scenario further complicated the uncertainty issue. The geographic distributions for precipitation difference among various simulations are very similar between the present and future climate with very high spatial pattern correlation coefficients. The result suggests that the model present climate biases are systematically propagate into the future climate projections. The impacts of the model present biases on projected future trends are, however, highly nonlinear and regional specific, and thus cannot be simply removed by a linear method. A model with more realistic present climate simulations is anticipated to yield future climate projections with higher credibility.  相似文献   

17.
席朝笠  曾新民  李宁 《气象科学》2007,27(4):355-364
采用数值模式方法对我国华东地区进行月尺度短期气候预测。预测框架由改进的低分辨率全球环流模式T63 L9嵌套并入了水文模型VXM的区域气候模式RegCM3构成,根据嵌套气候模式的积分结果,经剔除系统误差后制作短期气候预报。本文利用国家气候中心的评分方法对2003、2004两年的降水和地表气温回报结果作了评估;还将本系统的预报结果与CMAP降水资料、NMC温度资料及全国160站的观测资料进行了对比。结果表明,该系统可以比较稳定地对我国华东地区的降水和温度进行月尺度预测。  相似文献   

18.
In China, ten climate types were classified using the K-means cluster analysis based on monthly temperature and precipitation data from 753 national meteorological stations for the period 1966–2005. However, 11 mountain climate stations, which are located in southeast China, were classified as one type due to their distinct climate characteristic that differentiated them from other stations. This type could not represent the climate characteristic of this region because all climate stations in this type were located at high-elevation mountains. Thus, it was eliminated when defining climate zones based on climate types. Therefore, nine climate zones were defined in China. Moreover, the temporal change of climate zones was detected in 20-year intervals (1966–1985 and 1986–2005). Although 48 stations changed their climate zones between these two periods, the whole pattern of all climate zones remained stable in these two periods. However, the boundaries between some climate zones changed slightly due to inconsistent variation of regional temperature and precipitation. The most obvious change was the eastern movement of the boundary between an arid temperate zone and a sub-humid temperate zone. There was also a northern shift of the boundary between a tropic zone and a southern subtropic zone. All these changes were probably connected with the climate change in recent 40 years.  相似文献   

19.
We study the influence of station network density on the distributions and trends in indices of area-average daily precipitation and temperature in the E-OBS high resolution gridded dataset of daily climate over Europe, which was produced with the primary purpose of Regional Climate Model evaluation. Area averages can only be determined with reasonable accuracy from a sufficiently large number of stations within a grid-box. However, the station network on which E-OBS is based comprises only 2,316 stations, spread unevenly across approximately 18,000 0.22° grid-boxes. Consequently, grid-box data in E-OBS are derived through interpolation of stations up to 500 km distant, with the distance of stations that contribute significantly to any grid-box value increasing in areas with lower station density. Since more dispersed stations have less shared variance, the resultant interpolated values are likely to be over-smoothed, and extreme daily values even more so. We perform an experiment over five E-OBS grid boxes for precipitation and temperature that have a sufficiently dense local station network to enable a reasonable estimate of the area-average. We then create a series of randomly selected station sub-networks ranging in size from four to all stations within the E-OBS interpolation search radii. For each sub-network realisation, we estimate the grid-box average applying the same interpolation methodology as used for E-OBS, and then evaluate the effect of network density on the distribution of daily values, as well as trends in extremes indices. The results show that when fewer stations have been used for the interpolation, both precipitation and temperature are over-smoothed, leading to a strong tendency for interpolated daily values to be reduced relative to the “true” area-average. The smoothing is greatest for higher percentiles, and therefore has a disproportionate effect on extremes and any derived extremes indices. For many regions of the E-OBS dataset, the station density is sufficiently low to expect this smoothing effect to be significant and this should be borne in mind by any users of the E-OBS dataset.  相似文献   

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