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Persistent anomalous flows over the subtropical western Pacific insummer

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chinese Science Bulletin 1998年第8期43卷 672-675页

作者： ZHUANG Shiyu\+1.and JI Liren\+2 1. National meteorological Centre, {1. meteorological Administration, beijing 1.0081. {1. 2. LASG, Institute of Atmospheric Physics, chinese Academy of sciences, beijing 1.0080, {1. National meteorological Ccntre China Meteomlcgical Administration Beijing China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The distribution of global persistent anomalies shows that the subtropical western Pacific is a key region with high_frequency occurrence of persistent anomalies. Analyses of streamfunction anomalies, OLR anomalies etc. suggest that the convective heating related to Indian monsoon might be responsible for the development of WPA. The results of numerical experiment by two linear barotropic models support the observation.

关键词： persistent anomalies subtropical high Indian monsoon anomalous forcing.

Case studies on mesoscale structures of heavy rainfall system in the Yangtze River generated by Meiyu front

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Science china Earth {1. 2005年第8期48卷 1303-1311页

作者： LIU Liping1. RUAN Zheng1.& QIN Danyu2 1. chinese Academy of {1. sciences, beijing 1.0081. china 2. Nanjing Institute of Meteorology, Nanjing 21.044, china 1. chinese Academy of {1. sciences 100081 Beijing China 2. Nanjing Institute of Meteorology 210044 Nanjing China

A heavy rainfall system was observed over the Yangtze River during Meiyu season by using dual-Doppler radar systems in the field experiment conducted by the project of National Fundamental Research Planning “Research on formation mechanism and the prediction theory of hazardous weather over china”. The three-dimensional mesoscale kinematic structure and process of a heavy rain on 22 and 23 July, 2002 are investigated by using the radial velocity and dual-Doppler radar technique. The results show that a southwest-northeast oriented rain band with the length of about 1.00 km involves numbers of meso-β or meso-γ-scale convective cells with the size of 20―50 km. The heavy rain band in the middle reaches of the Yangtze River ex-ists in a low-level wind shear. The interaction between southwest low-level jet on the southern side of wind shear and east wind on the northern side formed the updraft. The wind disturbance, wind shear and convergence generate the convective action. The new cell developed in right rear flank of rain band and moved to the southwest wind area, where the vapor is abundant. This kind of echo can last a long time and developed well. The strong convective echoes are often ac-companied by the meso-γ-scale vortex and convergence.

关键词： heavy rainfall in Meiyu front, mesoscale structure, dual-Doppler radar, middle reaches of the Yangtze River, low-level jet.

Teleconnection between the Indian summer monsoon onset and the Meiyu over the Yangtze River Valley

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Science china Earth {1. 2008年第7期51卷 1021-1035页

作者： LIU YunYun1.2,3 & DING YiHui2 1.chinese Academy of {1. sciences, beijing 1.0081. china 2 National Climate Center, beijing 1.0081. china 3 Graduate University of chinese Academy of sciences, beijing 1.0049, china 1. chinese Academy of {1. sciences Beijing 100081 China 2. National Climate Center Beijing 100081 China 3. Graduate University of chinese Academy of {1. Beijing 100049 China

Based on the Indian and chinese precipitation data and the NCEP-NCAR reanalysis circulation data, the relationship between the Indian summer monsoon (ISM) onset and the Meiyu over the Yangtze River Valley has been discussed by the methods of correlation analysis and composite analysis. The results show that the date of ISM onset over Kerala in the southwestern coast of the Indian Peninsula is about two weeks earlier than the beginning of the Meiyu over the Yangtze River Valley. After the outbreak of ISM, the teleconnection mode sets up from the western coast of India via the Bay of Bengal (BOB) to the Yangtze River Valley and southern Japan. It is different both in time and space from the telecon- nection mode which is from the northwest of India via the Tibetan Plateau to northern {1.. The for- mer mode is defined as the "south" teleconnection of the Asian summer monsoon, forming in the pe- riod of ISM onset; while the latter mode is called the "north" teleconnection, mainly occurring in the Asian monsoon culminant period. During the process of the "south" teleconnection’s formation, the Asian monsoon circulation has experienced a series of important changes: ISM onset, the northward movement of the south Asia high (SAH), the onset vortex occurrence, the eastward extension of the stronger tropical westerly belt, and the northeastward jump of the western Pacific subtropical high (WPSH), etc. Consequently, since ISM sets up over Kerala, the whole Asian continent is covered by the upper SAH after about two weeks, while in the mid- and lower troposphere, a strong wind belt forms from the Arabian Sea via the southern India, BOB and the South {1. Sea (SCS), then along the western flank of WPSH, to the Yangtze River Valley and southern Japan. With the northward moving of the subtropical jet streams, the upper westerly jet stream and the low level jet have been coupled ver- tically over east Asia, while the Yangtze River Valley happens to locate in the ascending motion

关键词： Indian summer monsoon (ISM) the Meiyu over the Yangtze River Valley teleconnection mode

Relationship between the Asian-Pacific oscillation and the tropical cyclone frequency in the western North Pacific

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Science china Earth {1. 2008年第3期51卷 380-385页

作者： ZHOU BoTao1, CUI Xuan2 & ZHAO Ping3 1 Laboratory for Climate Studies, National Climate Center, china meteorological Administration, beijing 100081, china 2 National meteorological Center, china meteorological Administration, beijing 100081, china 3 chinese Academy of meteorological sciences, china meteorological Administration, beijing 100081, china 1. Laboratory for Climate Studies National Climate Center China Meteorological Administration Beijing 100081 China 2. National meteorological Center China Meteorological Administration Beijing 100081 China 3. chinese Academy of {1. sciences China Meteorological Administration Beijing 100081 China

The relationship between the Asian-Pacific oscillation (APO) and the tropical cyclone frequency over the western North Pacific (WNP) in summer is preliminarily investigated through an analysis of ob- served data. The result has shown clearly that APO is significantly and positively correlated to the tropical cyclone frequency in the WNP. If APO is above (below) the normal in summer, more (less) tropical cyclones will tend to appear in the WNP. The present study also addresses the large-scale at- mospheric general circulation changes underlying the linkage between APO and the WNP tropical cy- clone frequency. It follows that a positive phase of summer APO is concurrent with weakened as well as northward and eastward located western Pacific subtropical high (WPSH), low-level convergence and high-level divergence, and reduced vertical zonal wind shear in the WNP, providing favorable envi- ronment for the tropical cyclone genesis, and thus more tropical cyclones will come into being, and vice versa.

关键词： Asian-Pacific oscillation western North Pacific tropical cyclone atmospheric circulation

Mineralogy and crystal structure determination of Mg-fillowite

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Science china Earth {1. 2005年第5期48卷 635-646页

作者： MA Zhesheng 1., SHI Nicheng 1.& YE Danian 2 1. china University of Geo{1., beijing 1.0083, china 2. Institute of Geology, chinese Academy of {1., beijing 1.0029, china 1. china University of Geo{1. 100083 Beijing China 2. Institute of Geology Chinese Academy of Sciences 100029 Beijing China

Accurate crystal structure determination of complex phosphate Mg-fillowite ? Na2Ca(Mn4Mg2Fe)7[PO4]6 has been finished. Mg-fillowite occurs in muscovite-pegmatite in the Altay area, Xinjiang, china. It is of the trigonal lattice, with space group R-3, unit cell a=1.51.3(3) nm, c=4.31.1.2) nm, V=8.5736 nm3, Z = 1.. The R-factor of the determination accuracy is R (I > 2σ ( I )) = 0.0776. The cationic polyhedra consist of two kinds of structural units: compound col- umn and screw column. In three-dimensional space, they are linked with each other through corner sharing or edge sharing to build the entire structure. There are 45 atoms in an asymmetric unit and 720 atoms in a unit cell. In terms of types and connection manners of the coordination polyhedra, the degree of complicity is rarely seen in all mineral crystal structures. Study of such a structure is significant for the classification of phosphate and the building rule of coordination polyhedra in a complex crystal structure.

关键词： Mg-fillowite, complex phosphate, crystal structure, coordination polyhedron.

Explicit analytical solutions of the anisotropic Brinkman model for the natural convection in porous media(Ⅱ)

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Science china(Physics,Mechanics & Astronomy) 2005年第4期48卷 422-430页

作者： CAI Ruixian1. GOU Chenhua1. 2 & ZHANG Na1.1. Institute of Engineering Thermophysics, chinese Academy of {1., beijing 1.0080, china 2. Graduate School, chinese Academy of {1., beijing 1.0080, china 1. Institute of Engineering Thermophysics Chinese Academy of Sciences 100080 Beijing China 2. Graduate School Chinese Academy of Sciences 10080 Beijing China

Some algebraically explicit analytical solutions are derived for the anisotropic Brinkman model―an improved Darcy model―describing the natural convection in porous media. Besides their important theoretical meaning (for example, in analyzing the non-Darcy and anisotropic effects on the convection), such analytical solutions can be the benchmark solutions that can promote the development of computational heat and mass transfer. Some solutions considering the anisotropic effect of permeability have been given previously by the authors, and this paper gives solutions including the anisotropic effect of thermal conductivity and the effect of heat sources.

关键词： explicit analytical solution, porous medium, natural convection, Brinkman model, anisotropic.

Some key technics of drop tower experiment device of National Microgravity Laboratory (china) (NMLC)

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Science china(Technological {1.) 2005年第3期48卷 305-316页

作者： ZHANG Xiaoqian 1., YUAN Longgen 1., WU Wendong 1., TIAN Lanqiao 2 & YAO Kangzhuang 2 1. Institute of Engineering Thermophysics, chinese Academy of {1., beijing 1.0080, china 2. Institute of Mechanics, chinese Academy of {1., beijing 1.0080, china 1. Institute of Engineering Thermophysics Chinese Academy of Sciences 100080 Beijing China 2. Institute of Mechanics Chinese Academy of Sciences 100080 Beijing China

Drop tower is an important ground based facility for microgravity science experiment. The technical performances of the drop tower NMLC are advanced compared with similar facilities in the US, Germany and Japan. The main components such as drop capsule, deceleration devices, release mechanism present its advantages and creativities.

关键词： drop tower facility,drop capsule,deceleration devices,release mechanism.

ORDER RESULTS FOR ALGEBRAICALLY STABLEMONO-IMPLICIT RUNGE-KUTTA METHODS

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Journal of Computational Mathematics 1999年第6期17卷 639-644页

作者： Ai-guo Xiao(1. Department of Mathematics, Xiangtan University, Xiangtan 41.1.5, china2. ICMSEC, {1. Academy of sciences, beijing 1.080, china) Xiangtan Univ Dept Math Poona 411005 Maharashtra India chinese Acad Sci ICMSEC Beijing 100080 Peoples R China

It is well known that mono-implicit Runge-Kutta methods have been applied in the efficient numerical solution of initial or boundary value problems of ordinary differential equations. Burrage (1.94) has shown that the order of an s-stage monoimplicit Runge-Kutta method is at most s+1.and the stage order is at most 3. In this paper, it is shown that the order of an s-stage mono-implicit Runge-Kutta method being algebraically stable is at most min((s) over tilde, 4), and the stage order together with the optimal B-convergence order is at most min(s, 2), where [GRAPHICS]

关键词： ordinary differential equations mono-implicit Runge-Kutta methods order algebraical stability

Algebraically explicit analytical solu-tions for the unsteady non-Newtonian swirling flow in an annular pipe

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Science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 396-400页

作者： CAI Ruixian1.& GOU Chenhua1.2 1. Institute of Engineering Thermophysics, chinese Academy of {1., beijing 1.0080, china 2. Graduate School, chinese Academy of {1., beijing 1.0080, china 1. Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100080 China 2. Graduate School Chinese Academy of Sciences Beijing 100080 China

This paper presents two algebraically explicit analytical solutions for the incompressible unsteady rotational flow of Oldroyd-B type in an annular pipe. The first solution is derived with the common method of separation of variables. The second one is deduced with the method of separation of variables with addition developed in recent years. The first analytical solution is of clear physical meaning and both of them are fairly simple and valuable for the newly developing computational fluid dynamics. They can be used as the benchmark solutions to verify the applicability of the existing numerical computational methods and to inspire new differencing schemes, grid generation ways, etc. Moreover, a steady solution for the generalized second grade rheologic fluid flow is also presented. The correctness of these solutions can be easily proven by substituting them into the original governing equation.

关键词： analytical solution, Oldroyd-B type fluid, swirling flow, non-Newtonian.