水平网格对Rossby波的影响   总被引：7，自引：0，他引：7  

刘宇迪  季仲贞  朱红伟  李昕东  侯志明 《气象学报》2002,60(1):76-84

文中从描述准地转、β平面近似下的Rossby波方程组出发,在Arakawa A-E网格和Z网格上,分可分辨和不可分辨两种情况,从频率和群速方面讨论了这6种网格的计算频散性。结果表明:在可分辨的惰况下,Z,D,C网格比其它网格对Rossby波产生的歪曲都要小;而在不可分辨的情况下,这6种网格的描述能力都比较差。  相似文献   

非静力模式中几种垂直网格计算特性的对比研究   总被引：8，自引：0，他引：8  

Liu Yudi  Ji Zhongzhen  Wang Bin 《大气科学进展》2002,19(3):528-543

从非静力滞弹性方程组出发，将惯性重力波的水平波长分几百公里、几十公里和几公里三种情况，从频率、群速和各速的垂直尺度范围等方面对现有的几种垂直网格进行比较讨论。结果表明：在非静力模式中，CP网格和LZ网格适合于各种不同水平尺度惯性重力波的模拟；L网格和LY网格适合于水平尺度为几十公里以上的惯性重力波的模拟；LTS网格和CPTS网格比较适合于水平尺度的几十公里以下的惯性重力波的模拟。  相似文献   

基于新型LE水平跳点网格的阴阳网格平流方案设计     

艾细根  刘宇迪 《气象》2015,41(6):707-707

为了模拟球面平流传输过程,本文基于球面阴阳重叠网格设计了一种两时间层半拉格朗日平流方案.该方案在球面坐标下采用新型的LE水平跳点网格,同时针对阴阳网格重叠区,采用了不同插值方法进行比较分析,且进行了相关的理想数值试验对方案设计效果进行评估.数值试验表明方案设计是成功的,阴阳网格重叠区平流对插值方案比较敏感;半拉格朗日方案能较好地模拟球面刚体平流和变形涡旋的结构、位置及演变过程,并具有较好的数值稳定性和较高的数值精度.  相似文献   

基于球面阴阳网格数值计算研究进展     

艾细根  刘宇迪  崔新东  张涛 《气象科技》2014,42(1):13-22

对球面阴阳网格的转换关系、优缺点及边界数据插值交换方法的相关知识进行了较为详细介绍。同时对应用球面阴阳网格的3种数值计算方法进行了回顾总结,包括优化的Schwarz方法、CIP-CSLR平流数值计算方法、多离散矩有限体积法。针对优化的Schwarz方法,从浅水方程组的离散入手,讨论了其在求解球面椭圆型问题的优势;而对CIP-CSLR平流数值计算方法和多离散矩有限体积法,主要从如何在网格单元内构造插值函数的角度对其进行分析。最后对开发全球非静力阴阳网格模式进行展望。  相似文献   

松潘—甘孜造山带南缘江浪穹窿文家坪花岗岩的成因及地质意义     

朱玉娣  代堰锫  王丽丽  李同柱  张惠华  沈战武 《现代地质》2018,32(1):16

为厘定江浪穹窿文家坪花岗岩的侵位时代并探讨岩石成因,开展了地球化学、锆石U Pb年代学和Hf同位素研究。文家坪花岗岩岩性为黑云母花岗岩,由石英(约40%)、钾长石(约35%)、黑云母(约15%)及斜长石(<10%)等矿物组成。主微量元素分析表明,江浪穹窿文家坪花岗岩具有高的SiO2含量(6770%~7009%)、Na2O+K2O含量(743%~784%)、Zr+Nb+Ce+Y含量(363×10-6~476×10-6)、Mg#指数(359~387)及10 000×Ga/Al比值(258~284),显示右倾的稀土配分型式,富集大离子亲石元素、亏损高场强元素。锆石U Pb定年与Hf同位素示踪表明,花岗岩结晶年龄为(1646±09) Ma(n=21,MSWD=32),εHf(t)值介于-130~+14之间。综合研究提出,文家坪花岗岩属后造山A2型花岗岩,形成于岩石圈伸展构造背景,岩浆源区主要为江浪穹窿核部的中元古界里伍岩群及少量的幔源物质。结合其他地质成果,认为江浪穹窿成穹时代为早—中侏罗世,且区域Cu、W成矿作用很可能与约165 Ma花岗质岩浆活动具有成因联系。  相似文献   

浙西桐村斑岩型钼(铜)矿床与德兴斑岩铜矿岩浆岩对比研究   总被引：3，自引：0，他引：3  

朱玉娣  叶锡芳  张德会  王科强 《地球科学进展》2012,27(10):1043-1053

桐村地区与德兴矿区岩石系列相似,为高钾钙碱性系列;在岩石结构上,桐村地区花岗闪长岩为似斑状结构,德兴矿区花岗闪长斑岩为斑状结构。两者均为钙碱—碱质镁质I型花岗岩。桐村岩石富Si和K,A/CNK和K/(K+Na)值均小于德兴岩石。微量元素、同位素及岩石学特征表明桐村地区的物质来源以壳源为主,而德兴地区为有大量幔源物质参与的壳幔混合型,其原因可能与两区不同的构造位置有关。中晚侏罗世时,太平洋板块西向俯冲,下插板片发生部分熔融形成的岩浆与岩石圈地幔楔发生作用从而形成斑岩岩浆是桐村和德兴地区可能的成因模式。桐村矿床含矿斑岩的氧逸度、演化程度和地壳混染程度均较德兴斑岩铜矿高。对于同时代、近距离的岩浆岩形成如此规模悬殊的矿床还有许多问题值得研究和思考。  相似文献   

Reason and Condition for Mode Kissing in MASW Method     

Lingli Gao  Jianghai Xia  Yudi Pan  Yixian Xu 《Pure and Applied Geophysics》2016,173(5):1627-1638

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论园林景观地图     

应申  周钰笛  杜志强 《地理信息世界》2017,24(5)

提出了将园林景观设计图与地图融合的思路来构建园林景观地图。论文重点讨论园林景观设计与地图在表达内容、要素表达方法、空间理念等之间的互通之处,基于它们的关联分析,以香港斧山公园为例说明园林景观地图的实现方法。园林景观地图结合了园林景观设计与地图的优点,既有园林景观设计的写意与美观,又有地图的可量测性和现势性,有效地实现了地图抽象性与景观设计形象性的结合。  相似文献   

Variational data assimilation experiments of mei-yu front rainstorms in China   总被引：1，自引：0，他引：1  

WANG Yunfeng  WANG Bin  HAN Yueqi  ZHU Min  HOU Zhiming  ZHOU Yi  LIU Yudi  KOU Zheng 《大气科学进展》2004,21(4):587-596

The numerical forecasts of mei-yu front rainstorms in China has been an important issue. The intensity and pattern of the frontal rainfall are greatly influenced by the initial fields of the numerical model. The 4-dimensional variational data assimilation technology (4DVAR) can effectively assimilate all kinds of observed data, including rainfall data at the observed stations, so that the initial fields and the precipitation forecast can both be greatly improved. The non-hydrostatic meso-scale model (MM5) and its adjoint model are used to study the development of the mei-yu front rainstorm from 1200 UTC 25 June to 0600 UTC 26 June 1999. By numerical simulation experiments and assimilation experiments, the T106 data and the observed 6-hour rainfall data are assimilated. The influences of many factors, such as the choice of the assimilated variables and the weighting coefficient, on the precipitation forecast results are studied. The numerical results show that 4DVAR is valuable and important to mei-yu front rainfall prediction.  相似文献   

Assessment of the effects of vegetation on soil erosion risk by water: a case of study of the Batta watershed in Tunisia   总被引：2，自引：1，他引：1  

Mohamed Kefi  Kunihiko Yoshino  Yudi Setiawan  Khemaies Zayani  Mohamed Boufaroua 《Environmental Earth Sciences》2011,64(3):707-719

Soil erosion by water is a serious environmental problem which affects particularly the agriculture of developing countries. Due to specific factors, such as high rainfall intensity, steep slopes and vegetation scarcity, Tunisia is prone to soil erosion. Taking this into account, the main objective of this study was to estimate the soil erosion risk in the Batta watershed in Tunisia using qualitative and quantitative erosion model with remote sensing data and geographic information system (GIS). Moreover, a developed method that deals with evaluating the impact of vegetation on soil erosion by water is also applied. This method used multi-temporal satellite images with seasonal variability and the transformed soil adjusted vegetation index (TSAVI) which is appropriate in arid and semi-arid areas. For both erosion models, the results show that a large area of the Batta watershed is seriously affected by erosion. This potentially high risk is due especially to severe slopes, poor vegetation coverage and high soil erodibility in this watershed. Furthermore, the use of multi-temporal satellite images and vegetation index show that the effect of vegetation is a significant factor to protect the soil against erosion. The risk is especially serious in the summer season, but it decreases with the growth of vegetation cover in spring. Erosion model, combined with a GIS and remote sensing, is an adequate method to evaluate the soil erosion risk by water. The findings can be used by decision makers as a guideline to plan appropriate strategies for soil and water conservation practices.  相似文献