SEASONAL CIRCULATION IN THE NORTHWESTERN TROPICAL PACIFIC OCEAN DIAGNOSED WITH THE ASSIMILATION DATA FROM 1989 THROUGH 1997

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｔｈｅｗｅｓｔｅｒｎｅｑｕａｔｏｒｉａｌＰａｃｉｆｉｃＯｃｅａｎ ,ｔｈｅｖｉｇｏｒｏｕｓａｎｄｃｏｍｐｌｅｘｃｉｒｃｕｌａｔｉｏｎｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｔｈｅｕｎｉｑｕｅｃｏｎｖｅｒｇｅｎｃｅｏｆｔｈｅｓｕｒｆａｃｅｃｕｒｒｅｎｔｓ,ｐｅｒ ｍａｎｅｎｔ,ｓｅａｓｏｎａｌａｎｄｍｅｓｏｓｃａｌｅｅｄｄｉｅｓ ,ａｎｄｓｕｂｓｕｒ ｆａｃｅｃｕｒｒｅｎｔｓ.Ａｓａｎｉｍｐｏｒｔａｎｔｃｏｎｔｒｉｂｕｔｏｒｔｏｔｈｅｅ ｑｕａｔｏｒｉａｌａｎｄｇｌｏｂａｌｍｏｍ…     

古田溪四级大坝垂直位移的突变值解析

在定性分析古田溪四级大坝垂直位移观测资料的基础上，运用改进的统 计模型对其进行分析,以模拟大坝各坝段垂直位移观测资料中出现的两次突变现象。同时， 采用典型坝段的混合模型进行校核，解析出古田溪四级大坝垂直位移产生突变的原因。     

POTENTIAL APPLICATION FOREGROUND OF OCEAN MODE IN NAVY OCEANOGRAPHY

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＪｕｓｔａｓｌｉｇｈｔｃａｎｂｅｄｅｃｏｍｐｏｓｅｄｉｎｔｏ 7ｃｏｌｏｒｓａｎｄｍｕｓｉｃｉｎｔｏ 7ｎｏｔｅｓ,ｔｈｅｃｏｍｐｌｅｘｖｅｒｔｉｃａｌｐｒｏｆｉｌｅｓｏｆｏｃｅａｎｄｙｎａｍｉｃａｌｆａｃｔｏｒｓａｎｄｓｏｕｎｄｓｐｅｅｄｃａｎａｌｓｏｂｅｄｅｃｏｍｐｏｓｅｄｉｎｔｏａｓｅｒｉｅｓｏｆｎｏｒｍａｌｍｏｄｅｓ[1～ 5] .Ｂａｓｅｄｏｎｔｈｉｓｆａｃｔ,ｉｎｔｈｅｅａｒｌｙ 1 980ｓＡｍｅｒｉｃａａｃｔｕ ａｌｉｚｅｄｔｈｅＯｃｅａｎｉｃＡｃｏｕｓｔｉｃＴｏｍｏｇ…     

SEASONAL VARIABILITY OF THE INDONESIAN THROUGHFLOW FROM A VARIABLE-GRID GLOBAL OCEAN MODEL

1 .　INTRODUCTIONAsalow latitudepathwayforthewarm ,lowsalinityPacificwatersintotheIndianOcean ,In donesianThroughflow (ITF) playsanintegralpartintheglobalthermohalinecirculationandclimatephenomenon ,andtheheatandfreshwatercarriedbytheITFimpactsthebasinbudgetsofboththePacificandtheIndianOceans (WajsowiczandSchneider 2 0 0 1) .Although ,therecentobserva tionshaverevealedsomespatialandtemporalvari abilityfromintraseasonaltointerannualtimescales ,thereappearstobealargedifferenceinpeaktra…     

ANALYSIS OF FRAZIL JAM DATA FROM HEQU REACH OF THE YELLOW RIVER

ＡＮＡＬＹＳＩＳＯＦＦＲＡＺＩＬＪＡＭＤＡＴＡＦＲＯＭＨＥＱＵＲＥＡＣＨＯＦＴＨＥＹＥＬＬＯＷＲＩＶＥＲＷａｎｇＤｅ－ｓｈｅｎｇ；ＳｈｅｎｇＨｕｎｇ－ｔａｏ（ＤｅｐａｒｔｍｅｎｔｏｆＣｉｖｉｌａｎｄＥｎｖｉｒｏｎｍｅｎｔａｌＥｎｇｉｎｅｅｒｉｎｇＵｎ...     

SMW工法围护结构的设计

根据SMW工法的用途和特点,提出了该方法在围护工程中的设计计算理论和设计准则,总结出SMW工法的特点和优势,以便在今后的工程实践中更好的加以运用。     

EFFECT OF COOLED BOUNDARY ON THE TURBULENT STRUCTURE

1 .　INTRODUCTIONHeattransferintheheatexchangerchannelismainlyinthewayofconvection ,whichiscloselyrelatedtotheflowbehavioroffluid .Therefore ,itisnecessarytomakeathoroughinvestigationintotheflowmechanismbeforestudyingheattransferinsidetheheatexchanger .At present,measurementshaveextensivelymadefortheinvestigationoftheturbulentflowmechanism .Onthewhole ,forthecharacteristicsandstructuresoftheturbulentchannelflowwith outheattransferthroughtheboundary ,theresultsreportedhaveagreedquitewellwi…     

DYNAMICS OF THE ZONAL ASYMMETRIC STRUCTURE OF ARCTIC OSCILLATION

The Arctic Oscillation (AO), though basically is a zonal symmetric phenomenon, also shows zonal asymmetric variation. The dynamics of this zonal variation is considered here from the point of view of the planetary propagation on the earth sphere. Based on the linear barotropic vorticity equation, the planetary wave ray path is calculated in the winter January. It shows that NAO(North Atlantic Oscillation),AO and North Pacific could be linked through the planetary wave propagation, which acts as the atmospheric bridge. The zonal symmetric and asymmetric structures both have association with these Rossby wave activities.     

SENSITIVITY STUDY OF THE EFFECTS OF WAVE-INDUCED VERTICAL MIXING ON VERTICAL EXCHANGE PROCESSES

The hydrodynamic model COHERENS-SED, developed by the present authors through introducing wave-enhanced bottom stress, wave dependent surface drag coefficient, wave-induced surface mixing, SWAN to COHERENS, is modified to account for wave-induced vertical mixing. The COHERENS-SED model can also be used for one-dimensional, two-dimensional, three-dimensional current and salinity calculations. One-dimensional model and three-dimensional model are used to study the effects of the wave-induced vertical mixing. The horizontal current velocity profiles obtained by the model are in good agreement with the analytical velocity profiles under the same input conditions. Numerical results show that higher wave height would generally generate larger vertical eddy viscosity and lower horizontal velocity. The results for fresh water in Yellow River Delta show that the wave-induced vertical mixing increases the momentum of fresh water transferring ability downwards to seabed and salt water's mixing with upper fresh water. Fresh water flume length is compressed considerably.     

THE STRUCTURE AND SCALE EFFECT OF WALL TURBULENT FLOW

In this paper the structure and scale effect of wall turbulence are investigated.Thecharacteristics of the turbulence structure in the wall region is described.The fact that the turbu-lence in whole flow field is controlled mainly by the structure of wall turbulence is demonstrat-ed.Discussion is concentrated on the scale effects of the streak structure,the vortex structureand the bursting frequency.     

COUPLING COMPUTATION OF THE FLOW FIELD AND THE LARGE DEFORMATION OF MEMBRANE STRUCTURE OF STRATOSPHERE AIRSHIPS

In this article, the mathematical model of the coupling of the three-dimensional fluid flow and the large deformation of membrane structure is established. The fluid-structure coupling interaction is simulated using the computational codes developed by the authors. By analyzing the interactions of membrane and flow field, the aeroelasticity of the airship is detailed. All the results are adopted in the focused study of the stratosphere airship in trimmed state.     

A STUDY ON VARIABILITY OF SEA SURFACE TEMPERATURE IN TROPICAL PACIFIC, INDIAN OCEAN AND RELATED AIR CIRCULATION

1 .　INTRODUCTIONOceanscover 71%oftheearth’ssurface ,ab sorb 70 %ofthesolarradiationenergy ,85 %ofwhichisstoredintheoceanicsurfacelayerasaheatsourcedrivingair seamotion ,andsuppy 86%ofthemoistureintheair .Thethermalanddy namicinertiamakestheoceanhavespecial“re membrance”and“low passfilter”roleforatmo sphericvariation .Therefore ,thevariabilityofoceanicthermalsituationandair seainteractionareoneoftheimportantfactorscausingtheshortrangeclimaticchanges[1] .Namias ( 195 9) putfor wardthe…     

THE EFFECT OF LONGITUDINAL OSCILLATIONS ON FREE CONVECTION FROM A VERTICAL PLATE EMBEDDED IN A POROUS MEDIUM

In this paper oscillatory 2-D natural convection from a vertical isothermal wall embedded in a po-rous medium, and originating from the oscillation of longitudinal fluid flow, has been investigatedboth analytically and numerically. Two asymptotic solutions, valid for large and small values ofdimensionless frequency γ respectively, are obtained in the closed form. In the range where the asymptoticsolutions break down, numerical results to the governing equations are obtained by local similarity meth-od. Both numerical and analytical results show that pulsatory components of the flow and heat transferdepend only on the parameter γ, and the effect of longitudinal oscillation is to decrease the magnitude or"pulsatory Nusselt number with a phase lag between 0 and 90 deg. A correlation for pulsatory heat trans-fer rates is proposed in the whole range of γ within 3% accuracy compared with the numerical results.     

AN ACCURATE SOLUTION OF THE LINEAR THEORY OF THE WIND-DRIVEN OCEAN CIRCULATION-I. THE GENERALIZED SOLUTION

To model the wind-driven ocean circulation of the isobath rectangular basin, the linear vorticity equation with the meridional friction term was used compared to the Munk's theory on the ocean circulation. The generalized solution of the vorticity equation was thus worked out in the sense of Fourier averaging by using the corrected Fourier expansion. The method to obtain the undetermined coefficients was presented using the viscous boundary conditions.     

ESTIMATING THERMAL REGIMES OF BULL TROUT AND ASSESSING THE POTENTIAL EFFECTS OF CLIMATE WARMING ON CRITICAL HABITATS

Understanding the vulnerability of aquatic species and habitats under climate change is critical for conservation and management of freshwater systems. Climate warming is predicted to increase water temperatures in freshwater ecosystems worldwide, yet few studies have developed spatially explicit modelling tools for understanding the potential impacts. We parameterized a nonspatial model, a spatial flow‐routed model, and a spatial hierarchical model to predict August stream temperatures (22‐m resolution) throughout the Flathead River Basin, USA and Canada. Model comparisons showed that the spatial models performed significantly better than the nonspatial model, explaining the spatial autocorrelation found between sites. The spatial hierarchical model explained 82% of the variation in summer mean (August) stream temperatures and was used to estimate thermal regimes for threatened bull trout (Salvelinus confluentus) habitats, one of the most thermally sensitive coldwater species in western North America. The model estimated summer thermal regimes of spawning and rearing habitats at <13°C and foraging, migrating, and overwintering habitats at <14°C. To illustrate the useful application of such a model, we simulated climate warming scenarios to quantify potential loss of critical habitats under forecasted climatic conditions. As air and water temperatures continue to increase, our model simulations show that lower portions of the Flathead River Basin drainage (foraging, migrating, and overwintering habitat) may become thermally unsuitable and headwater streams (spawning and rearing) may become isolated because of increasing thermal fragmentation during summer. Model results can be used to focus conservation and management efforts on populations of concern, by identifying critical habitats and assessing thermal changes at a local scale. Copyright © 2012 John Wiley & Sons, Ltd.     

NUMERICAL MODELLING OF THE QUASI-GLOBAL OCEAN CIRCULATION BASED ON POM

A free surface quasi-global ocean circulation model, Princeton Ocean Model (POM), was adopted to simulate the climatological circulation. The horizontal resolution of the model was 1/2~X 1/2~ with 16 vertical sigma layers. The initial temperature and salinity fields of the model were interpolated from the Levitus data, and the COADS(Comprehensive Ocean-Atmosphere Data Set ) monthly mean SST and wind fields were used as the surface forcing. The integral time length is 6a. The main general circulation components such as the equatorial current, the equatorial undercurrent, the south and north equatorial currents, the Antarctic Circumpolar Current (ACC), the Kuroshio and the Gulf Stream were well reconstructed. The volume transports of PN section and ACC agree well with the estimations on field survey. Up to now there is no global or quasi-global circulation model results using POM in literature. Our results demonstrate that POM has sound ability to simulate the coastal circulation as well as the general ocean circulation. And this result can provide open boundary conditions for fine resolution regional ocean circulation models.     

THE ANALYSIS OF INTRASEASONAL LONG ROSSBY WAVE SPEED IN THE SUBTROPICAL PACIFIC OCEAN

1. INTRODUCTIONLong Rossby waves are the main mechanis mwherebyinformation about one part of the oceanistransferred to another part and a nonequilibriumo-cean state adjusts to an equilibriumone . The studyon the beta views of long Rossby waves is an i m-portant aspect of ocean circulation. In a recentstudy , Chelton and Schlax[1]conducted a thoroughanalysis of the satellite alti meter data from thefirst 3 years TOPEX/POSEIDON mission. Theyfound two interesting properties of long Ro…     

土坝垂直防渗加固技术方案优化初探

简要介绍土坝垂直防渗技术的现状，阐明土坝垂直防渗加固技术方案设计准备工作的内容、拟定和优化选择方案的方法，并通过工程实例说明优化方案取得的效果。     

浅议岩石质量指标(RQD)的统计方法

用传统回次统计法和用分段统计法对上千个钻孔的RQD值的统计结果表明,选用回次统计法普遍存在与工程实际情况产生一定的偏离;若用孔段统计法,其结果与工程实际情况比较吻合.     

THERMAL IMAGING STUDY OF SCALAR TRANSPORT IN SHALLOW WAKES

The thermal imaging technique relies on the usage of infrared signal to detect the temperature field.Using temperature as a flow tracer,thermography is used to investigate the scalar transport in the shallow-water wake generated by an emergent circular cylinder.Thermal imaging is demonstrated to be a good quantitative flow visualization technique for studying turbulent mixing phenomena in shallow waters.A key advantage of the thermal imaging method over other scalar measurement techniques,such as the Laser Induced Fluorescence(LIF)and Planar Concentration Analysis(PCA)methods,is that it involves a very simple experimental setup.The dispersion characteristics captured with this technique are found to be similar to past studies with traditional measurement techniques.