Testing the Ability of Numerical Model to Simulate Climate and Its Change With 4D-EOF Analysis     

ZHAO Deming  SU Bingkai  TANG Jianping 《Acta Meteorologica Sinica》2007,21(2):179-191

The four-dimensional empirical orthogonal function (4D-EOF), which in reality is a simple combination of three-dimensional EOF (3D-EOF) and extended EOF (EEOF), is put forward in this paper to test the ability of numerical model to simulate climate and its change. The 4D-E0F analysis is able to reveal not only the horizontal characteristic pattern of analyzed variable, and its corresponding annual and inter-annual variations, but also the vertical structural characteristics. The method suggested is then used to analyze the monthly mean 100-, 500-, 70G-, and 1000-hPa geopotential height fields (4941 grids and grid spacing 60 km) and their anomaly fields in 1989-1998 simulated by the MM5V3 from the RMIP (Regional Climate Model Inter-comparison Project for East Asia)-II, as well as their counterparts (used as the observed fields) from the NCEP/NCAR re-analysis dataset in the same period. The ability of MM5V3 in simulating East Asian climate and its change is tested by comparing the 4D-EOF analysis results of the simulated and observed datasets. The comparative analyzed results show that the horizontal pattern of the first eigenvector of the observed monthly mean geopotential height fields and its vertical equivalent barotropic feature were well simulated; the simulations of the first two eigenvectors of the observed monthly mean geopotential height anomaly fields were also successful for their horizontal abnormal distributions and significant equivalent barotropic features in the vertical were well reproduced; and furthermore, the observed characteristics, such as the variation with height, the annual and inter-annual variations of the monthly mean geopotential height/anomaly fields were also well reflected in the simulation. Therefore, the 4D-EOF is able to comprehensively test numerical model's ability of simulating the climate and its change, and the simulation ability of MM5V3 for the climate and its change in East Asia in the 1990s was satisfactory.  相似文献   

区域卫星导航系统GEO卫星定轨观测模型   总被引：1，自引：0，他引：1  

陈刘成  李建文  唐波 《武汉大学学报(信息科学版)》2007,32(7):609-613

根据GEO导航卫星的轨道特性，给出了数学上严密的卫星伪距观测和载波相位观测模型，讨论了GEO卫星轨道和卫星钟差的解算条件以及单星定轨、多星组差定轨的可行性。  相似文献   

一种新型的遥感影像压缩质量评价指标     

翟亮  唐新明  李霖  洪志刚 《武汉大学学报(信息科学版)》2007,32(10):872-875

针对遥感影像的特性,提出了一个用于压缩质量评价的多维结构模型,该结构模型由影像特征畸变、纹理畸变和相关性损失三个"维"组成,在此基础上提出一种新的构像质量综合性评价指标。实验证明,该指标与传统的PSNR指标相比,与主观评价结果具有较好的吻合性。  相似文献   

全数字摄影测量室内判调方法的应用     

夏荣  弓美荣 《测绘技术装备》2007,9(1):42-43

本文阐述了航测法成图制作1:1万地形数据工作过程中,采用全数字摄影测量工作站对地物进行室内判调“先内后外”的作业方法,并通过对获取的成果与常规方法的对比,证明此法在实际生产中具应用价值。  相似文献   

Late Cambrian to Early Silurian Granitic Rocks of the Gemuri Area, Central Qiangtang, North Tibet: New Constraints on the Tectonic Evolution of the Northern Margin of Gondwana     

WANG Haitao  ZHAI Qingguo  HU Peiyuan  ZENG Lingsen  TANG Yue  ZHU Zhicai 《《地质学报》英文版》2020,94(4):1007-1019

The Paleozoic tectonic framework and paleo–plate configuration of the northern margin of Gondwana remain controversial. The South Qiangtang terrane is located along the northern margin of Gondwana and records key processes in the formation and evolution of this supercontinent. Here, we present new field, petrological, zircon U-Pb geochronological, and Lu-Hf isotopic data for granitic rocks of the Gemuri pluton, all of which provide new insights into the evolution of the northern margin of Gondwana. Zircon U-Pb dating of the Gemuri pluton yielded three concordant ages of 488.5 ± 2.1, 479.9 ± 8.9, and 438.5 ± 3.5 Ma. Combining these ages with the results of previous research indicates that the South Qiangtang terrane records two magmatic episodes at 502–471 and 453–439 Ma. These two episodes are associated with enriched zircon Hf isotopic compositions(εHf(t) =-10.1 to-3.9 and-16.6 to-6.5, respectively), suggesting the granites were formed by the partial melting of Paleoproterozoic–Mesoproterozoic metasedimentary rocks(Two–stage Hf model ages(TCDM) = 2094–1704 and 2466–1827 Ma, respectively). Combining these data with the presence of linearly distributed, contemporaneous Paleozoic igneous rocks along the northern margin of Gondwana, we suggest that all of these rocks were formed in an active continental margin setting. This manifests that the two magmatic episodes within the Gemuri area were associated with southward subduction in the Proto-(Paleo-) Tethys Ocean.  相似文献   

电感耦合等离子体发射光谱法测试地质样品中的基体效应及校正办法     

杨柳  唐振  王海娇 《地质与资源》2020,29(3):289-293

电感耦合等离子体发射光谱（ICP-AES）法分析速度快、干扰较少并能同时测定多种元素，被广泛应用于地质调查样品的分析测试中，成为通用的无机化学元素分析测试工具.在测定复杂基体样品时，由于基体效应产生的各种干扰也会影响分析测试结果，包括光谱干扰、物理干扰、化学干扰、电离干扰等.以ICAP-6000型号仪器为例，结合仪器特点及实际工作经验，对复杂基体地质样品测定中出现干扰的原因、特点进行分析，探讨基体消除的方法以保障测试结果的准确性.  相似文献   

基于Weibull分布的红砂岩颗粒崩解破碎演化规律     

张宗堂  高文华  张志敏  唐骁宇  邬俊 《岩土力学》2020,41(3):877-885

红砂岩在我国分布广泛，由于含水率的变化使其崩解破碎十分显著。采用湖南株洲地区的红砂岩样，进行室内静态与扰动崩解试验。基于Weibull分布建立了红砂岩颗粒崩解破碎级配曲线演化模型，分析了模型参数λ与k的意义。分析表明，Weibull分布参数λ与k的大小及变化速率体现了红砂岩颗粒崩解破碎的演化过程。在建立模型的基础上，求得了相对崩解比的计算公式，并验证了计算公式的正确性。依据试验结果与模型计算值，讨论了耐崩解性指数与崩解比的异同及所采用试验方法的不同对试验结果造成的影响。在已有成果的基础上，验证了Weibull分布模型应用于岩石颗粒崩解破碎演化过程的可行性。  相似文献   

利用数值模拟方法对类星体-星系团引力透镜成因的再考察     

朱晓红 《中国天文和天体物理学报》1998,(1)

利用星系团形成的数值模拟技术所得到的星系团以及大尺度结构,本文研究了星系团和其周围环境物质的引力透镜效应对背景类星体计数的影响,以期解释最近观测到的类星体星系团成协现象．然而,得到的结果却是：用星系团及所遵循的大尺度结构的引力透镜效应,不能解释所观测到的类星体数密度．这与解析方法所得结论一致．分析表明：目前所观测到的类星体与星系团成协,如果不是统计涨落,则无法用引力透镜效应来解释。  相似文献   

三颗河外射电源第一历元的VLBI图像     

洪晓瑜  万同山  蒋栋荣  沈志强  刘祥 《中国天文和天体物理学报》1998,(4)

本文给出利用上海、乌鲁木齐、意大利ＮＯＴＯ和南非ＨａｒｔＲＡＯ射电望远镜,对三颗河外射电源（１５３２＋０１６,２３２００２０,２３５１１５４）,在５ＧＨｚ频率上的第一历元ＶＬＢＩ观测成图结果  相似文献   

气球天文观测计算机测控系统设计     

李小青 《紫金山天文台台刊》1998,17(3):30-35

球栽STD总线数据采集与控制系统是为气球X射线天文观测研制的新一代计算机控制系统。它采用了多项新技术与新方法,是一个模块化的多CPU多任务并行处理系统。本文详细描述了它的结构和各种工作组态,并给出了地面实测结果。  相似文献