检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

大气斜压性与入海江淮气旋发展的个例研究

海洋学报 2002年第S1期24卷 95-104页

作者：马雷鸣秦曾灏端义宏杜秉玉上海台风研究所上海200030 南京气象学院江苏南京210044

在详细分析 1 990年、1 993年 6月两个东海气旋入海发展的大尺度环境条件的基础上 ,利用倾斜涡度发展理论 (SVD)建立了风垂直切变与垂直涡度的联系 ,并进行了分析和验证 .结果表明 :在气旋入东海发展初期 ,其所在区域风垂直切变的增强... 详细信息

在详细分析 1 990年、1 993年 6月两个东海气旋入海发展的大尺度环境条件的基础上 ,利用倾斜涡度发展理论 (SVD)建立了风垂直切变与垂直涡度的联系 ,并进行了分析和验证 .结果表明 :在气旋入东海发展初期 ,其所在区域风垂直切变的增强有利于气旋发展 .另外 ,对高空急流与气旋发展的关系进行了探讨 ,伴随气旋发展高空西风急流强度有所增强 ,在气旋整个生命期中气旋位置有从高空急流入口区的南侧向出口区的北侧移动的趋势 .

关键词：倾斜涡度发展风垂直切变大气斜压性江淮气旋

在线全文

学校读者我要写书评

暂无评论

海洋热通量对东海气旋发展影响的数值试验

海洋学报 2002年第S1期24卷 112-122页

作者：马雷鸣秦曾灏端义宏杜秉玉上海台风研究所上海200030 南京气象学院江苏南京210044

利用PSU/NCARMM 4对东海两个弱气旋个例的初期入海发展进行了数值模拟和敏感性试验的研究 ,并对主要结果进行了分析 .采用总体空气动力学边界层及显式水汽方案的控制试验较成功地模拟出了气旋涡度场的型式和中心强度 .在此基础上针对海... 详细信息

利用PSU/NCARMM 4对东海两个弱气旋个例的初期入海发展进行了数值模拟和敏感性试验的研究 ,并对主要结果进行了分析 .采用总体空气动力学边界层及显式水汽方案的控制试验较成功地模拟出了气旋涡度场的型式和中心强度 .在此基础上针对海洋热通量进行了敏感性试验 .结果表明 ,海洋热通量输送对东海气旋的发展有非常重要的作用 .不计初期海洋热通量输送可减少模拟气旋强度的 4 5%以上 ;初始 (入海前 )增加海 -气温差 1K可使气旋强度增加 2.% ;初始增加海洋潜热输送 (海 -气饱和水汽差 ) 1 %使气旋强度增加 50 %左右 .潜热输送的贡献约为感热的2.0倍 .海洋热输送加大了低层大气的不稳定性。

关键词：东海气旋数值模拟敏感性试验

AN EXPERIMENTAL STUDY ON THREE DIMENSIONAL STRUCTURE OF BAROCLINIC WAVY JET STREAM IN A ROTATING ANNULUS SUBJECT TO RADIAL TEMPERATURE GRADIENT

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2000年第4期12卷 26-35页

作者： Su Xiao bin, Wei Gang Hydrodynamics Department of meteorology College, P. L. A. University of Science and Engineering. nanjing, 2.1101, P.R.{2. (Received Dec.1, 1999) Hydrodynamics Dep. Meteorology Coll. PLA Univ. of Sci. and Eng. Nanjing 211101 China

Three dimensional structure of baroclinic wavy jet was experimentally studied in rotating annulus subject to a negative radial temperature gradient. General features of wavy surface jet in the system were obtained. Based on the precise measurements of velocity distribution of the jet with LDV and the three dimensional temperature field in the convective system, three dimensional thermodynamic structures of jet were gained, and by using a correlation of three dimensional disturbed temperature, the unstable mechanism of disturbed temperature of baroclinic fluid in a rotating system was further discussed.

关键词： baroclinic wave rotating fluid jet correlation coefficien8

Statistical characteristics of the double ridges of subtropical high in the Northern Hemisphere

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2005年第20期 82-87页

作者： ZHAN Ruifen1,2.3, LI Jianping1 & HE Jinhai2. 1. State Key Laboratory of Numerical Modeling for Atmospheric Sci- ences and Geophysical Fluid Dynamics (LASG), Institute of Atmos- pheric Physics, Chinese Academy of Sciences, Beijing 10002., china 2. Department of Atmospheric Sciences, Institute of meteorology, Nan- jing University of Information Science and Technology, {2. 2.0044, china 3. Graduate School of the Chinese Academy of Sciences, Beijing 100039, china

The generality and some climatological charac- teristics of the double ridge systems of subtropical high (SH) are investigated statistically by using the daily NCEP/NCAR reanalysis data from 1958 to 1998. The results show that the SH double-ridge event is a common phenomenon in the Northern Hemisphere, with the distinct seasonal and re- gional features, that is, the majority of SH double-ridge geneses concentrate over the eastern North India Ocean- western North Pacific as well as the central North Pacific in the period from mid-July to mid-September. Especially over the western North Pacific subtropics, the SH double-ridge events are extremely active. It is found that the life cycle of most double-ridge events of western Pacific subtropical high (WPSH) is shorter but some still last longer. The WPSH dou- ble-ridge events occur most frequently from July to Septem- ber, while there is a paucity of occurrences during Novem- ber-March. Also, it is shown that the WPSH double-ridge events have a strong interannual variation with a certain periodicity which possesses a remarkably abrupt change in the mid-1970s. Additionally, the relationship between the WPSH double ridges and the meridional movement of WPSH is discussed.

关键词： subtropical high double ridges statistical characteristics meridional movement.

Interhemispheric atmospheric mass oscillation and its relation to interannual variations of the Asian monsoon in boreal summer

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2010年第9期53卷 1343-1350页

作者： LU ChuHan, GUAN ZhaoYong & CAI JiaXi Key Laboratory of Meteorological Disaster of Ministry of Education and College of Atmospheric Sciences, nanjing University of Information Science & Technology, nanjing 2.0044,{2. Key Laboratory of Meteorological Disaster of Ministry of Education and College of Atmospheric Sciences Nanjing University of Information Science & Technology Nanjing China

Using NCEP/NCAR reanalysis and precipitation records of Chinese stations, we have investigated the relationship of interhemispheric oscillation of air mass (IHO) with global lower-level circulation and monsoon anomalies in boreal summer. Our results show that the summer IHO explains a greater portion of variance in the abnormal distribution of atmospheric mass over 30°S-60°N as well as the Antarctic. The IHO strongly correlates to the variations of sea level pressure (SLP) in these regions. It is shown that IHO has some influences on both atmospheric mass transports and water vapor fluxes over 30°S-60°N in association with three anomalous cyclonic circulations over land areas of the eastern hemisphere, which is in close relation to the changes in summer monsoon intensity in eastern Asia and western Africa. Composites of summer rainfall anomalies in china for high and low IHO-index years indicate that the eastern Asian summer monsoon is more intense, with positive precipitation anomaly centers in northern and northeastern parts of china, as opposed to the negative center over the mid-lower reaches of the Yangtze River (MLRYR) in stronger IHO years. In weak IHO years, a feeble summer monsoon appears in eastern Asia, leading to positive center of precipitation anomalies displaced into the MLRYR. Furthermore, a teleconnection in wind fields between the western African and eastern Asian monsoon regions was observed in the middle and higher troposphere in the scenario of IHO. The anomalous cyclonic (anticyclonic) circulations along the path of this Africa-East Asia teleconnection were found to be just over the diabatic heating (cooling) centers, suggesting that diabatic forcings are responsible for the formation of this Africa-East Asia teleconnection.

关键词： interhemispheric oscillation Asian monsoon precipitation china boreal summer

NUMERICAL SIMULATIONS OF SEA ICE WITH DIFFERENT ADVECTION SCHEMES

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2011年第3期23卷 372-378页

作者： LIU Xi-ying State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Institute of meteorology PLA University of Science and Technology Nanjing 211101 China

Numerical simulations are carried out for sea ice with four different advection schemes to study their effects on the simulation results. The sea ice model employed here is the Sea Ice Simulator （SIS） of the Geophysical Fluid Dynamics Laboratory （GFDL） Modular Ocean Model version 4b （MOM4b） and the four advection schemes are, the upwind scheme originally used in the SIS, the Multi-Dimensional Positive Advection （MDPA） scheme, the Incremental Remapping Scheme （IRS） and the Two Step Shape Preserving （TSSP） scheme. The latter three schemes are newly introduced. To consider the interactions between sea ice and ocean, a mixed layer ocean model is introduced and coupled to the SIS. The coupled model uses a tri-polar coordinate with 12.x65 grids, covering the whole earth globe, in the horizontal plane. Simulation results in the northern high latitudes are analyzed. In all simulations, the model reproduces the seasonal variation of sea ice in the northern high latitudes well. Compared with the results from the observation, the sea ice model produces some extra sea ice coverage in the Greenland Sea and Barents Sea in winter due to the exclusion of ocean current effects and the smaller simulated sea ice thickness in the Arctic basin. There are similar features among the results obtained with the introduced three advection schemes. The simulated sea ice thickness with the three newly introduced schemes are all smaller than that of the upwind scheme and the simulated sea ice velocities of movement are all smaller than that of the upwind scheme. There are more similarities shared in the results obtained with the MPDA and TSSP schemes.

关键词： advection scheme sea ice simulation

EFFECT OF INSTABILITIES OF FLOW ON MESOSCALE PREDICTABILITY OF WEATHER SYSTEMS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2011年第2期23卷 193-203页

作者： LUO Yu ZHANG Li-feng Institute of meteorology PLA University of Science and Technology Nanjing 211101

The numerical solution of Boussinesq equations is worked out as an initial-value problem to study the effect of the instabilities of flow on the initial error growth and mesoscale predictability. The development of weather systems depends on different dynamic instability mechanisms according to the spatial scales of the system and the development of mesoscale systems is determined by symmetric instability. Since symmetric instability dominates among the three types of dynamic instability, it makes the prediction of the associated mesoscale systems more sensitive to initial uncertainties. This indicates that the stronger instability leads to faster initial error growth and thus limits the mesoscale predictability. Besides dynamic instability, the impact of thermodynamic instability is also explored. The evolvement of convective instability manifests as dramatic variation in small spatial scale and short temporal scale, and furthermore, it exhibits the upscale growth. Since these features determine the initial error growth, the mesoscale systems arising from convective instability are less predictable and the upscale error growth limits the predictability of larger scales. The latent heating is responsible for changing the stability of flow and subsequently influencing the error growth and the predictability.

关键词： instabilities of flow mesoscale system predictability initial errors

Construction of Optimal Truncated Low-Dimensional Dynamical systems directly from PDEs

在线全文

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 1998年第1期3卷 1-5页

作者： Hongliang ZHAO, Chuijie WU(LNM, Institute of Mechanics, CAS, Beijing, 100080) (Air Force Institute of meteorology, nanjing, 2.1101) Email: cjwu@*** LNM Institute of Mechanics CAS Beijing 100080 China Air Force Institute of meteorology Nanjing 211101 China

ＩｎｔｒｏｄｕｃｔｉｏｎＷｈｅｎａｐｐｌｙｉｎｇｔｈｅｍｅｔｈｏｄｓｏｆｄｙｎａｍｉｃａｌｓｙｓｔｅｍｓｔｏｓｔｕｄｙｔｈｅｄｙｎａｍｉｃａｌｂｅｈａｖｉｏｒｏｆｓｏｍｅＰＤＥｓ，ｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｓｔ... 详细信息

ＩｎｔｒｏｄｕｃｔｉｏｎＷｈｅｎａｐｐｌｙｉｎｇｔｈｅｍｅｔｈｏｄｓｏｆｄｙｎａｍｉｃａｌｓｙｓｔｅｍｓｔｏｓｔｕｄｙｔｈｅｄｙｎａｍｉｃａｌｂｅｈａｖｉｏｒｏｆｓｏｍｅＰＤＥｓ，ｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｓｔｅｐｉｎｔｈｅｐｒｏｃｅｓｅｓｉｓ...

关键词： low dimensional dynamical system partial differential equations optimization

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

大气扰动及其对无人机自动着陆影响仿真研究

系统仿真学报 2009年第21期21卷 6821-6824页

作者：黄华陆汉城徐幼平北京应用气象研究所北京100029 解放军理工大学大气科学博士后流动站南京211101

基于流体动力学原理,建立三维非对称微下击暴流模型,同时耦合vorkarman湍流模型,对1982.7月9日美国新奥尔良微下击暴流案例进行了仿真模拟,并与多普勒雷达资料进行了对比。在其基础上,利用Matlab/Simulink仿真工具,针对某型无人机,建... 详细信息

基于流体动力学原理,建立三维非对称微下击暴流模型,同时耦合vorkarman湍流模型,对1982.7月9日美国新奥尔良微下击暴流案例进行了仿真模拟,并与多普勒雷达资料进行了对比。在其基础上,利用Matlab/Simulink仿真工具,针对某型无人机,建立了非线性六自由度飞行模型和自动着陆控制系统,并在大气扰动条件下,对该无人机的自动着陆过程进行了飞行仿真。仿真结果表明:所构建的微下击暴流模型简捷可靠,可有效反映真实案例的基本风场结构;作为大气扰动的主要形式,微下击暴流、湍流耦合效应对于无人机自动着陆任务的完成具有较大的影响。

关键词：微下击暴流湍流无人飞行器飞行仿真自动着陆