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1.
选用湖北省77个代表站1960-2003年逐日气温观测资料,分析了湖北省气温的年、季节变化规律及其地域分布特征.结果表明:湖北省近44年气温呈上升趋势,至2003年气温上升了0.5℃,增温速率约为0.12℃/10a,和近50年来的全球平均增温速率相当.20世纪90年代升温最剧烈.春季、秋季和冬季气温均呈上升趋势,冬季增温最明显,而夏季气温却呈下降趋势.夏季平均日最高气温也呈下降趋势,冬季平均日最低气温上升趋势显著.气温变化不同的地区差异较大,西部地区变化趋势不明显,有微弱的下降趋势,而中东部地区则有较明显的升温趋势.  相似文献   

2.
晋南地区近50年来气温与降水量变化趋势分析   总被引:1,自引:0,他引:1  
利用隰县、临汾、运城3个地面气象站1961年-2010年的气温和降水量资料,研究了晋南地区近50年来气温与降水量的变化趋势.研究表明,晋南地区1961年~2010年间年均气温呈上升趋势,增温速率为0.35℃/IOa,高于山西省和全国气温平均增长率,并且年均气温的上升主要源于冬春季节的快速升温.同时,该区60年代和70年代为相对寒冷期,80年代为相对平稳期,而90年代和本世纪前十年为相对温暖期,特别是本世纪前十年增温趋势十分明显.晋南地区近50年来年平均降水量以18.3mm/lOa的速率减少,并且夏秋季节对年降水量减少的贡献最大.该区60年代和70年代为相对多雨期,而90年代和本世纪前十年则为相对少雨期,特别是90年代,降水减少的幅度更明显.  相似文献   

3.
我国总云量时空特征及其影响因素分析   总被引:1,自引:0,他引:1  
目的分析中国总云量的时空分布特征、变化趋势及影响原因。方法利用全国360个地面站1951~2009年地面月总云量观测资料,采用线性倾向估计和相关分析方法。结果总云量最多区域位于西南和华南地区,最少位于北部干旱少雨地区。约35°N以北总云量从南到北随纬度增加带状分布减少,此纬度以南同纬度东部云量多于西部云量。20世纪90年代以及21世纪前10年总云量减少最明显。总云量减少最明显的区域位于东北、西藏西南部以及山东、安徽北部地区。大部分地区总云量与太阳黑子相对数、降水量、相对湿度、最大积雪深度之间存在显著正相关关系,蒸发量与总云量存在显著负相关关系。结论我国总云量总体上呈减少趋势,气候因素对总云量变化有重要影响。  相似文献   

4.
利用耦合的气候模式CESM, 定量研究青藏高原对全球大气温度和水汽分布的影响。通过对比采用真实地形的参考实验(Real)和去掉青藏高原的敏感性实验(NoTibet)发现, 去掉青藏高原会使北半球大气变冷、变干, 对南半球的影响不明显。北半球中高纬度从地表至平流层均有强烈降温, 地表的降温中心在北大西洋, 年平均降温幅度达5ºC, 高空的降温中心在100 hPa的平流层, 年平均降温幅度达2ºC。北大西洋和南亚地区湿度减少, 南大西洋和东非地区湿度增加。北半球变冷主要是海洋向北经向热量输送减少的结果, 一方面增强了北半球的经向温度梯度, 导致Hadley环流增强, 加强了中低纬地区向北的大气热量输送, 部分补偿了海洋向北减少的热量输送, 维持了北半球中低纬度的能量平衡; 另一方面, 使得北半球中高纬度蒸发作用减弱, 大气中水汽含量减少, 北半球变得寒冷干燥。初步的研究表明, 青藏高原对北半球气候有重大影响, 影响范围可达北半球高纬度地区。  相似文献   

5.
全球气候变暖背景下的大气环流基本模态   总被引:10,自引:0,他引:10  
利用NCEP/NCAR REANALYSIS1948年1月~2001年2月1000~100hPa的高度场资料研究全球纬圈平均大气环流的变化.EOF1显示全球纬圈平均大气高度场在高纬度和低纬度地区呈明显的反向变化,这一变化特点解释了总方差的一半左右.从时间系数上看,近53年低纬度高度上升,高纬度高度下降.这表明20世纪60年代以后,特别是20世纪80年代中期以后,对流层中纬度西风有明显的加强趋势.与全球平均地面气温变化比较证明这种大气环流的变化与全球平均地面气温的变化有显著的相关.用观测海温强迫运行大气环流模式积分两个50年(1900~1950年和1950~1999年),EOF1与再分析资料所得的EOF1特征十分相似,解释的方差大小也基本一致.伴随着近20年的全球气温的剧烈上升,低纬度高度场升高,高纬度高度场降低,两个半球中纬度西风显著加强成为全球大气环流变化的最主要特征.  相似文献   

6.
中国北方水汽与云和降水的关系   总被引:5,自引:1,他引:4  
利用中国35°N以北地区1961年1月1日-2001年12月31日58个探空站逐日高空观测资料以及地面观测的逐日总云量、低云量、降水量资料,分析了42a来中国北方各区水汽质量分数的变化特征,水汽质量分数与总云量、低云量以及降水量的年际变化特征,逐区讨论了水汽质量分数与总云量、低云量和降水量的相关关系.结果表明:中国北方地区42a水汽质量分数有微弱的增加;水汽质量分数与云量、降水量呈明显的正相关.水汽质量分数与云量、降水量的相关中,平均水汽质量分数与低云量、降水量的正相关最显著;云量与降水量的相关中,低云量与降水量的相关最显著.这三种相关的季节变化特征均为春季最显著,秋、夏季次之,冬季最弱.沙区的各相关系数均低于非沙区的,说明荒漠化对空中水资源也有一定的影响,尤其是在沙尘暴多发的春季,这一影响就更显著了.  相似文献   

7.
对近年来山地气温变化研究的相关文献进行分析,以世界著名山脉欧洲的阿尔卑斯山、亚洲的青藏高原和喜马拉雅山、北美洲的科罗拉多落基山和南美洲的热带安第斯山为例,探讨全球变化背景下山地气温变化的规律和区域差异,气温变化的海拔高度依赖规律,以及冰雪反射、云量、大气水汽、气溶胶对山地气温变化的影响.结果表明:目前尚无足够的证据证明山地的暖化速率高于地球陆地表面的其他地区,但无论是台站观测还是气候模型模拟都发现了气温变化的海拔高度依赖规律,即寒冷季节的最低温度和温暖季节的最高温度均有不同程度地随山地海拔高度增加而升高的趋势;冰雪覆盖及反射的变化是山地增温速率变化的主要影响因子.  相似文献   

8.
利用1961~2005年南宁市最高、最低和平均温度资料,分析近50a来南宁市的气温变化特征,通过气候变暖前后灾害性天气气候事件的对比,分析南宁市灾害性天气气候事件的变化规律。结果表明,1961~2005年南宁市年平均气温增温趋势明显,温度变率为0.3C/10a,各季节平均气温均呈上升趋势,秋季增温最明显,冬季次之,夏季位居第三,春季增温最小。年平均最高气温呈较弱的增暖,变率为0.13C/10a,而年平均最低气温的增暖趋势比年平均最高气温明显,为0.36C/10a。年平均日校差的变化则呈递减的趋势,变率为-0.23C/10a。在全球气候增暖和城市化快速发展的过程中,南宁市的灾害性天气气候事件发生了明显的变化:极端强降水有增加趋势,高温天气明显增多,持续高温天气加剧,雷暴和大风日数明显减少,春季低温阴雨天气减少。南宁市灾害性天气气候事件变化的原因可能与全球气候变暖有关,城市化可能是造成南宁市灾害性天气气候事件变化的主要原因。  相似文献   

9.
近十几年新疆水汽源地变化特征   总被引:21,自引:0,他引:21  
提出确定新疆水汽源地的原则和步骤,用ERA-40再分析资料计算了新疆至大西洋沿岸对流层4个季节典型月份的定常水汽输送场,结合大气可降水量分析了气候意义上新疆的主要水汽源地及近十几年的变化.研究结果表明新疆的水汽主要来自其以西的湖泊或海洋,1,4月的水汽源地是里海和地中海;7月是北大西洋和北冰洋;10月是黑海和里海.再分析资料和观测资料分析都发现,1987年后随着全球增暖,7月和1月中高纬度行星尺度大气的水汽含量增加,地中海所在纬度带减少;新疆上空的水汽更多地直接来自于较高纬度带,来自地中海所在纬度带的水汽输送减少了.  相似文献   

10.
基于2008-2013年全球天气预报系统(GFS)预报场资料,构造了30个云预报因子,分析了其与低云量的相关关系,采用多元逐步回归预报方法建立了黄河河套周边地区低云量0~168 h逐小时精细化区域预报,评估了预报模型的预报效果.结果表明,低云量与水汽类因子整层湿度和整层相对湿度具有较强的正相关性;与大气可降水量、低层温度露点差和总温度具有较强的负相关性;与GFS云类预报因子有较强的正相关性.在预报方程中水汽类预报因子和GFS云量因子具有较高的引用频数.多元逐步回归方法低云量预报值与实况的差值明显低于直接使用GFS低云量的预报结果,在夏季逐步回归方法对低云量有较大改进,上半年对低云量的订正效果强于下半年.逐步回归方法对西北部低云量的订正能力高于东南部地区,部分地区的订正能力在20%以上.  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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