FEATURES OF WATER VAPOR TRANSPORT OF TYPHOON DAN (9914)     

邓国  周玉淑  于占江 《热带气象学报(英文版)》2006,12(1):46-54

The 2.5^。×2.52^。 gridded ECMWF reanalysis data are used to diagnose the genesis, development and dissipation of typhoon Dan by calculated stream function, velocity potential and vapor budget. It is shown in the result that when typhoon Dan moved westwards, water vapor mainly came from the eastern and western boundaries, with most of it was transferred by the easterly flow south of the western North Pacific subtropical high; after Dan swerved northwards, water vapor mainly came from western boundary of the typhoon, and the vapor came from the South China Sea and the Indian Ocean. The transfer of water vapor was mainly concentrated on the mid-lower troposphere, especially the level of 925hPa, at which the most intensive transfer belt was located. During the different period of typhoon Dan, there was great water vapor change as indicated by stream function, velocity potential and vapor budget, which suggest the importance of water vapor in the development of typhoon Dan.  相似文献   

华北平原冬麦田土壤CH4的吸收特征研究   总被引：9，自引：0，他引：9  

张雪松  申双和  李俊  于强 《南京气象学院学报》2006,29(2):181-188

利用静态箱/气相色谱(GC)法,对华北平原冬小麦拔节—成熟期间麦田土壤CH4气体通量进行了测定,得出华北平原典型冬麦田土壤是大气CH4的弱吸收汇。试验期间土壤CH4通量存在明显的季节变化和日变化,麦田拔节—成熟期间土壤CH4通量日平均值为-18.3μg.m-2.h-1,波动范围为-4.3~-24.4μg.m-2.h-1;在土壤CH4通量的日变化中,观测到麦田土壤在午间和夜间都有一个吸收峰,峰值出现的时间因生育期不同而有所不同。试验期间CH4通量日平均值与土壤温度关系不明显,而与土壤水分呈负相关(α=0.01);日变化中土壤CH4通量与地表温度的相关性较差,而与5 cm地温相关密切。麦田拔节—成熟期间土壤CH4通量日平均值随NH4 -N施用量的增加呈递减规律,农田秸秆还田后不利于土壤对CH4的吸收。  相似文献   

战场环境可视化中多源遥感影像数据处理     

廖云  余旭初  杨国鹏 《测绘学院学报》2006,(1)

介绍了将多源遥感影像数据应用于战场环境可视化之前的主要预处理方法,如影像金字塔生成、纹理数据结构准备、纹理快速调用等。该过程中所用到的小波变换、四叉树数据结构与细节层次算法等关键技术,能够有效地提高战场建模的真实感和效率。  相似文献   

强震记录与地震烈度的仪器测定实例     

朱建钢  黎大虎  赖敏  周朝晖  孙玮  余桦  代宽洪  颜晓晔 《四川地震》2006,(2):28-31,47

“十五”期间,四川强震台网将达到211个子台的规模。若仅按强震观测最基本的技术目标,用足够长的时间收集足够多的强震记录为抗震设计理论服务,显然未能尽其投资潜力。为此,我们将中国地震局工程力学研究所固化在该所GDQJ-1A数字强震仪内的烈度模式识别算法提取到台网中心计算机的后台,使“十五”建设采用的所有强震仪均“升级”成为可以现场测定地震烈度的设备。本文以2005年1月5日马尔康日部5.0级地震为例,展开强震台网的烈度测定和震灾快速评估。  相似文献   

钢筋混凝土桥墩非线性地震反应分析   总被引：2，自引：0，他引：2  

朱东生  虞庐松 《世界地震工程》2006,22(2):24-28

采用Takeda滞回曲线模型,对三个不同周期的桥墩,分别输入多条具有相同反应谱的地震波,计算了桥墩的线性和非线性时程响应,通过比较线性和非线性最大地震位移响应发现,在这些地震波作用下,虽然线性位移响应最大值基本相同,但非线性位移响应最大值差别很大。  相似文献   

内蒙古地区中强地震序列特征研究     

胡博  徐建德  于红梅 《华北地震科学》2006,24(4):6-11

根据内蒙古地震台网记录报告,对内蒙古地区中强地震(Ms≥5.0)的序列类型进行分析判断,对研究区地震序列类型的地区分布作了总结,并对不同类型序列与地质构造环境的关系作了简单分析,结果对本区今后的中强地震趋势判定有一定帮助。  相似文献   

ZHANG Heng’s Seismometer and Longxi earthquake in AD 134     

冯锐  俞言祥 《地震学报(英文版)》2006,(6)

Introduction Houhan Shu?ZHANG Heng Biography written by FAN Ye(AD398?AD445,South-North Dynasties)described about the response of ZHANG Heng’s Seismometer to Longxi earthquake as follows.“On one occasion a dragon dropped a ball without an earthquake being felt.All the scholars in the capital blamed this effect happening without any feelings of the earthquake.Several days later,a messenger arrived reporting that an earthquake really had taken place at Longxi.There-upon people all a…  相似文献   

EFFECT OF FLOW CONDITIONS ON 3D MOVEMENT CHARACTERISTICS OF PARTICLES     

Limo TANG Shanghong ZHANG Mingzhong YU Xingkui WANG 《国际泥沙研究》2006,21(4):272-280

1 INTRODUCTION The mechanism of particle movement in the flow is one of basic problems of sediment transport research. The conventional measurement approaches usually disturb the structure of the flow, consequently inducing errors. With the development of…  相似文献   

Relationships between δ18O in summer precipitation and temperature and moisture trajectories at Muztagata, western China   总被引：1，自引：0，他引：1  

YU Wusheng  YAO Tandong  TIAN Lide  LI Zhen  SUN Weizhen  WANG Yu 《中国科学D辑(英文版)》2006,49(1)

Based on summer observations of stable isotope of precipitation at Muztagata, western China, during 2002―2003, this paper presents the relationship between δ18O in precipitation and air temperature, and discusses the effect of moisture transport on δ18O in precipitation. Results show that air temperature correlates positively with δ18O in precipitation, and the temperature effect controls the δ18O of precipitation in this area. The Muztagata region exhibits high δ18O values in summer precipitation, similar to those shown at stations in adjacent regions. According to the results of our model set up to trace the moisture trajectories, the westerlies and local moisture circulation contribute to variations of oxygen isotopes in precipitation. In addition, the impacts of the moisture transport distance, the moisture transport level, and the incursion of the polar air mass also influence the variations of δ18O in precipitation. The moisture origins and transport mechanisms also contribute to the variation of δ18O in precipitation at Muztagata.  相似文献   

EXPERIMENTS OF A REDUCED GRID IN LASG/IAPWORLD OCEAN GENERAL CIRCULATION MODELS (OGCMs)     

刘喜迎  刘海龙  张学洪  宇如聪 《热带气象学报(英文版)》2006,12(1):9-15

Due to the decrease in grid size associated with the convergence of meridians toward the poles in spherical coordinates, the time steps in many global climate models with finite-difference method are restricted to be unpleasantly small. To overcome the problem, a reduced grid is introduced to LASG/IAP world ocean general circulation models. The reduced grid is implemented successfully in the coarser resolutions version model L30T63 at first. Then, it is carried out in the improved version model LICOM with finer resolutions. In the experiment with model L30T63, under time step unchanged though, execution time per single model run is shortened significantly owing to the decrease of grid number and filtering execution in high latitudes. Results from additional experiments with L30T63 show that the time step of integration can be quadrupled at most in reduced grid with refinement ratio 3. In the experiment with model LICOM and with the model’s original time step unchanged, the model covered area is extended to the whole globe from its original case with the grid point of North Pole considered as an isolated island and the results of experiment are shown to be acceptable.  相似文献