Errata: Intermediate Circulation in the Northwestern North Pacific Derived from Subsurface Floats     

Takanori Iwao  Masahiro Endoh  Nobuyuki Shikama  Toshiya Nakano 《Journal of Oceanography》2004,60(2):517-517

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Pre-Japan-ARGO: Experimental Observation of Upper and Middle Layers South of the Kuroshio Extension Region Using Profiling Floats     

Naoto Iwasaka  Toshio Suga  Kensuke Takeuchi  Keisuke Mizuno  Yasushi Takatsuki  Kentaro Ando  Taiyo Kobayashi  Eitarou Oka  Yasuko Ichikawa  Motoki Miyazaki  Hiroshi Matsuura  Kenji Izawa  Chan-Su Yang  Nobuyuki Shikama  Momoko Aoshima 《Journal of Oceanography》2003,59(1):119-127

We deployed two profiling floats in the region south of the Kuroshio Extension in March 2000. Temperature and salinity profiles from a depth of 1500 × 10⁴ Pa to the surface are reported every two and four weeks, respectively. The floats performed very well for first four months after deployment. Later they failed in surfacing for a few months when the sea surface temperature in the region was high. The salinity sensors seemed to suffer from some damage during their failure-in-surfacing period. Despite this trouble, the results clearly demonstrate that the profiling float is a very useful and cost-effective tool for physical oceanographic observation in the open sea. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Decreasing precipitation extremes at higher temperatures in tropical regions     

Eduardo Eiji Maeda  Nobuyuki Utsumi  Taikan Oki 《Natural Hazards》2012,64(1):935-941

It has been often accepted that rising troposphere temperatures will lead to higher precipitation intensities. This argument is based on the Clausius?CClapeyron (C?CC) relation, which indicates an increase in atmospheric moisture storage capacity of approximately 7?% K^?1. However, recent studies carried out in mid-latitude regions indicate that changes in precipitation intensity as a function of temperature do not necessarily follow the C?CC relation. This study aimed to evaluate the correlation between precipitation extremes and temperature in tropical regions, using measured data obtained at low latitude ranges over Brazil. The results indicate that, at daily timescale, the C?CC relation alone is unlikely to explain the relation between precipitation extremes and temperatures in tropical regions. Additional aspects, such as moisture availability and the duration of precipitation events, should be further analyzed to allow a comprehensive understanding of the relationship between temperature and precipitation intensity. Moreover, we show that in tropical regions, higher temperatures may reduce the magnitude of extreme precipitation events at daily timescales, independent of the season of the year.  相似文献   

乌鲁木齐天文站在月球探测同波束干涉测量中的作用     

王震  叶楠  尚堃  刘庆会  王娜  刘祥  艾力·玉  花田英夫  河野宣之 《天文学进展》2010,28(4)

首先简要介绍同波束干涉测量技术,随后叙述中国科学院国家天文台乌鲁木齐天文站在2008年成功完成了约200 h日本月球卫星SELENE同波束较差甚长基线干涉测量,并阐述乌站在此次VLBI中的作用。给出利用SELENE的观测数据,分析、解算出乌站25 m天线与日本VERA网相关台站基线Rstar、Vstar的S1、S2、S3、X频段的较差相关相位、较差相关相位残差,以及对各频段的较差相关相位、较差相关相位残差比对,最后获得较差相位时延。结果显示,同波束甚长基线干涉测量比传统VLBI观测得到的群时延精度提高了1～2个量级。  相似文献   

Arc-parallel extension in preparation of the rotation of southwest Japan: Tectonostratigraphy and structures of the Lower Miocene Ichishi Group     

Hideki Kinoshita  Atsushi Yamaji 《Island Arc》2021,30(1):e12418

Opening of the Japan Sea back arc basin was accompanied by extensional tectonics in the drifting southwest Japan arc. Various trends of Early Miocene grabens in the arc suggest multi-directional rifting, which necessarily involved strike-slip components of some of basin-margin faults. However, such components are not well understood. In this work we conducted a field survey in the Early Miocene Ichishi basin on the northern side of the Median Tectonic Line, central southwest Japan. We found that the basin was a compound of grabens that were formed along normal and sinistral strike-slip faults, the latter of which had northeast–southwest trends. The block faulting in this phase produced basement highs between sub-basins, which were filled with the lower part of the Ichishi Group. We found a low-angle angular unconformity at a middle horizon in the group, with which we define the upper and lower part of the group. The upper part onlapped both the basement highs and the lower part. It means that the transtensional basin formation ceased sometime between 18 and 17.5 Ma in the Ichishi area. The Ichishi basin turned subsequently into a sag basin subsided due to normal faulting probably along the Nunobiki-sanchi-toen fault zone. The transtension and the basin sag were driven by ENE–WSW extensional stress. This arc-parallel extension produced grabens various areas including Ichishi in the Early Miocene. The extensional deformation was eventually localized to the deep rift along the Fossa Magna to make the lithosphere under southwest Japan decoupled from that under northeast Japan. The decoupling allowed the rapid rotation of southwest Japan from ~17.5 Ma. The cluster of those grabens around the Ise bay probably determined the southeastern margin of the Kinki triangle.  相似文献   

Interaction between waves and an array of floating porous circular cylinders   总被引：1，自引：0，他引：1  

赵芬芳  鲍伟光  黄六一  梁振林  万荣 《中国海洋工程》2012,26(3):397-412

The present study theoretically as well as experimentally investigates the interaction between waves and an array of porous circular cylinders with or without an inner porous plate based on the linear wave theory.To design more effective floating breakwaters,the transmission rate of waves propagating through the array is evaluated.Each cylinder in the array is partly made of porous materials.Specifically,it possesses a porous sidewall and an impermeable bottom.In addition,an inner porous plate is horizontally fixed inside the cylinders.It dissipates the wave more effectively and eliminates the sloshing phenomenon.The approach suggested by Kagemoto and Yue(1986) is adopted to solve the multiple-scatter problem,while a hierarchical interaction theory is adopted to deal with hydrodynamic interactions among a great number of bodies,which efficiently saves computation time.Meanwhile,a series of model tests with an array of porous cylinders is performed in a wave basin to validate the theoretical work and the calculated results.The draft of the cylinders,the location of the inner porous plate,and the spacing between adjacent cylinders are also adjusted to investigate their effects on wave dissipation.  相似文献   

The dynamical architecture and habitable zones of the quintuplet planetary system 55 Cancri     

Jiang-Hui Ji Hiroshi Kinoshita Lin Liu Guang-Yu Li 《天体物理学报》2009,(6):703-711

We perform numerical simulations to study the secular orbital evolution and dynamical structure of the quintuplet planetary system 55 Cancri with the self-consistent orbital solutions by Fischer and coworkers. In the simulations, we show that this system can be stable for at least 108 yr. In addition, we extensively investigate the planetary configuration of four outer companions with one terrestrial planet in the wide region of 0.790AU 〈 a 〈 5.900AU to examine the existence of potential asteroid structure and Habitable Zones （HZs）. We show that there are unstable regions for orbits about 4：1, 3：1 and 5：2 mean motion resonances （MMRs） of the outermost planet in the system, and several stable orbits can remain at 3：2 and 1：1 MMRs, which resembles the asteroid belt in the solar system. From a dynamical viewpoint, proper HZ candidates for the existence of more potential terrestrial planets reside in the wide area between 1.0 AU and 2.3 AU with relatively low eccentricities.  相似文献   

Periodic solutions of the third sort for restricted problem of three bodies and their stability     

Yoshihide Kozai  Hiroshi Kinoshita 《Celestial Mechanics and Dynamical Astronomy》1973,7(2):156-176

In this paper periodic solutions of the third sort for restricted problem of three bodies in the three-dimensional space are derived numerically by starting from generating solutions obtained by one of the authors (1969) and by increasing the mass-ratio of the two primaries stepwise from zero to about 1000 for 21, 32 and 61 cases of commensurable mean motions. Periodic solutions both for circular and elliptic orbits of the primaries are obtained.The stability of the periodic solutions for the 21 circular case is discussed and it is found that none of them is linearly stable.  相似文献   

Nonuniform Distribution Of High-Frequency Turbulence In The Unstable Boundary Layer     

Nobuyuki Kinoshita 《Boundary-Layer Meteorology》2003,106(1):61-91

Turbulent flow data of wind velocity and temperature in the unstably stratifiedatmospheric boundary layer, derived from steel tower observations in the field and wind-tunnel experiments were used to study the relationship between the plumes and the small-scale eddies in the inertial subrange. Flow visualisation experiments in the wind tunnel were also conducted to observe the structure of the flow in the plumes, and time series data were analysed by using wavelet transforms. The results show that variances of velocity and temperature due to the small-scale eddies are large in the plumes and small outside of the plumes, and that the momentum and heat fluxes due to the small-scale eddies follow the same tendency as found in the variances. The ratios of the variances caused by the small-scale eddies in the plumes to the whole of the variances caused by the small-scale eddies in and out the plumes increase with non-dimensional height -z/L in which L is the local Obukhov length. Similar ratios of the fluxes caused by the small-scale eddies also show the same tendency. These ratios can be expressed as functions of -z/L for results based on field observationand the wind tunnel experiments. This relation hardly changes even if the wavelet function is changed. The flow visualisation experiments show that the plumes have a complicated structure in which mushroom type flows are stacked on top of each other. This characteristic structure seems to increase the energy of the small-scale eddies in the plumes.  相似文献   

Damage to Residential Fills in the 1995 Hanshin-Awaji Earthquake     

Nobuyuki Yoshida  Masaru Nishi  Mitsuhiro Nanbu 《Natural Hazards》2001,23(1):87-97

This paper summarizes the features of ground damage toresidential fills due to the 1995 Hyogo-ken NanbuEarthquake in Japan. Many residential lands sufferedground damage to various extents in the earthquakeevent. Permanent deformation took place ingently-sloping residential fills. Some slopes asgentle as four degrees exhibited landslide-likedownward movements from dozens to hundreds ofcentimeters, so on. It is suggested that liquefactionmight be a dominant factor for displacements ingently-inclined residential fills.  相似文献