A composite analysis of diurnal cycle of GPS precipitable water vapor in central Japan during Calm Summer Days     

G. Li  F. Kimura  T. Sato  D. Huang 《Theoretical and Applied Climatology》2008,92(1-2):15-29

Summary The diurnal variations of water vapor in central Japan were investigated with GPS-derived precipitable water (PWV) and surface meteorological data as classified to three kinds of locations. Twenty-five clear days in central Japan in August 2000 were investigated to clarify the role of water vapor in the nocturnal maximum in the diurnal cycle of convective rainfall. The diurnal variations of PWV and some meteorological factors were composite during the selected days at 6 stations. The PWV shows a clear diurnal cycle with the amplitude of 3.4 mm to 8.8 mm and changes little during the period from the morning to noon. The daily amplitude of PWV is the largest in basin and smallest in plain although mean of PWV keeps high value in plain. A typical feature of the diurnal variation in central Japan is a maximum appearing in the evening. The time of maximum is from 1800 LST to 2000 LST, and minima appears at noon nearly in mountainous area and basin, while in early morning in plain. The diurnal maximum of PWV appears earlier in mountainous region than in plain. A diurnal cycle of specific humidity can be observed in all locations, and the amplitude in mountainous region is especially large compared with that in basin and plain. It is important to notice that there are remarkable differences in specific humidity among the six stations. The results suggest that the diurnal variation of PWV seems to be strongly affected by the local thermal circulations generated by the topography around these stations. The moisture transport causes the differences in phase of the diurnal cycle of PWV between different locations as well as the phase difference in precipitation. A very clear diurnal variation in surface air temperature is similar to that of solar radiation, with a minimum in the morning and a maximum in early afternoon. Maximum of surface wind speed are corresponded to peak of precipitation very well. It can be concluded that the amplitude of solar radiation increases with altitude as opposed to the situation of PWV generally. The precipitation observed frequently in the evening also shows a similar diurnal variation to that of the PWV, indicating the peak of precipitation appearing in late afternoon or in the evening over central Japan. Meanwhile the PWV reaches its nocturnal maximum. There is a good relationship between the diurnal cycle of observed precipitation and that of the PWV. Authors’ addressess: Guoping Li, Department of Atmospheric Sciences, Chengdu University of Information Technology, #3 Section 3, Ren Min Nan Road, Chengdu, Sichuan 610041, P.R. China; Dingfa Huang, Department of Surveying Engineering, Southwest Jiaotong University, Chengdu, China; Fujio Kimura, Tomonori Sato, Institute of Geoscience, University of Tsukuba, Tsukuba, Japan.  相似文献   

The origin of chaotic behaviour in the Miranda-Umbriel 3 : 1 resonances     

Jacques Henrard  Massae Sato 《Celestial Mechanics and Dynamical Astronomy》1989,47(4):391-417

We have investigated the pericentric resonances through which Miranda and Umbriel are believed to have passed when, due to tidal evolution, their orbital mean motions reached a 3 : 1 commensurability. Our investigation is based upon a perturbative treatment. The predictions of this theory are in good agreement with the results of numerical integrations concerning both the extend of the chaotic layers generated by the separatrices of the primary resonances and the location of the secondary resonances. The effect of tidal evolution is discussed on the bases of the adiatatic invariant theory and its extension to separatrix crossing. We recover qualitatively the mean features of the numerical experiments of Tittermore and Wisdom (1988–1989), Dermott et al (1988) and Malhotra and Dermott (1989).  相似文献   

The 2004 June Bootid meteor shower     

J. Vaubaillon  R. Arlt  S. Shanov  S. Dubrovski  M. Sato 《Monthly notices of the Royal Astronomical Society》2005,362(4):1463-1471

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The quasi-stationary coronal magnetic field and electron density as determined from a Faraday rotation experiment     

C. T. Stelzried  G. S. Levy  T. Sato  W. V. T. Rusch  J. E. Ohlson  K. H. Schatten  J. M. Wilcox 《Solar physics》1970,14(2):440-456

Pioneer VI was launched into a circumsolar orbit on December 16, 1965, and was occulted by the sun in the latter half of November, 1968. During the occultation period, the 2292-MHz S-band telemetry carrier underwent Faraday rotation due to the interaction of this signal with the plasma and magnetic field in the solar corona. The NASA/JPL 210-ft diameter antenna of the Deep Space Network near Barstow, California, was used for the measurement. The antenna feed was modified for automatic polarization tracking for this experiment. The measurement results are interpreted with a theoretical model of the solar corona. This model consists of a modified Allen-Baumbach electron density and a coronal magnetic field calculated both from Mount Wilson magnetograph observations using a source surface model and field extrapolations from the Explorer 33 satellite magnetometer. The observations and the calculated rotation show general agreement with respect to magnitude, sense, and timing, suggesting the source-surface model and field extrapolations from 1 AU are a valid technique to obtain the magnetic field in the corona from 4 to 12 solar radii. Variations present can easily be ascribed to density enhancements known to be present in the corona. Longitudinal variations of the density in the corona cannot be obtained from coronagraph observations, and thus a purely radial variation was assumed. An improved fit to the Faraday rotation data is obtained with an equatorial electron density $$N = 10^8 \left( {\frac{{6000}}{{R^{10} }} + \frac{{0.002}}{{R^2 }}} \right)...{\text{ cm}}^{{\text{ - 3}}} {\text{ (4 < }}R < 12){\text{ }}...$$ where R is in solar radii. The work of W. V. T. Rusch and J. E. Ohlson was supported in part by research sponsored by the Joint Services Electronics Program through the Air Force Office of Scientific Research under Grant AF-AFOSR 69-1622A at the University of Southern California. The work done by K. H. Schatten was in part supported by the National Academy of Science on a National Research Council postdoctoral fellowship. The work of J. M. Wilcox was supported in part by the Office of Naval Research under Contract Nonr 3656(26), by the National Aeronautics and Space Administration under Grant NGR 05-003-230, and by the National Science Foundation under Grant GA-1319 at the University of California at Berkeley.  相似文献   

Laboratory analogy of crystalline enstatite grain formation in plasma field     

T. Sato  K. Kamitsuji  Y. Kimura  O. Kido  Y. Saito 《Planetary and Space Science》2006,54(6):617-620

Crystalline enstatite (MgSiO₃) grains were produced by the simultaneous evaporation of SiO grains and Mg vapor in a plasma field. The MgSiO₃ grains were spherical or needlelike. The necessity of a plasma field in astromineralogy is suggested in the present study.  相似文献   

Elastic Boundary Conditions In Long-Period Core Oscillations   总被引：4，自引：0，他引：4  

D. E. Smylie  A. M. K. Szeto  Kachishige Sato 《Geophysical Journal International》1990,100(2):183-192

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A spectroscopic study of Epsilon Aurigae     

Mamoru Saitō  Shusaku Kawabata  Keiich Saijo  Hideo Sato 《Astrophysics and Space Science》1984,99(1-2):269-272

Epsilon Aurigae has been observed during ingress and totality between 1982 and 1983 at Okayama. Analyses of profiles of H line and of radial velocities of neutral hydrogen and metals show that the secondary component consists of at least three parts in structure.Paper presented at the Lembang-Bamberg IAU Colloquium No. 80 on Double Stars: Physical Properties and Generic Relations, held at Bandung, Indonesia, 3–7 June, 1983.  相似文献   

Deep seismic reflection profiling across the Ou Backbone range, northern Honshu Island, Japan     

Hiroshi Sato  Naoshi Hirata  Takaya Iwasaki  Makoto Matsubara  Takeshi Ikawa   《Tectonophysics》2002,355(1-4)

Knowledge of the crustal structure, especially the geometry of seismogenic faults, is key to understanding active tectonic processes and assessing the size and frequency of future earthquakes. To reveal the relationship between crustal structure and earthquake activity in northern Honshu Island, common midpoint (CMP) deep reflection profiling and earthquake observations by densely deployed seismic stations were carried out across the active reverse faults that bound the Ou Backbone range. The 40-km-long CMP profiles portray a relatively simple fault geometry within the seismogenic layer. The reverse faults merge at a midcrustal detachment just below the base of the seismogenic layer, producing a pop-up structure that forms the Ou Backbone range. The top of the reflective middle to lower crust (4.5 s in travel time (TWT)) nearly coincides with the bottom of seismogenic layer. The P-wave velocity structure and surface geology suggest that the bounding faults are Miocene normal faults that have been reactivated as reverse faults.  相似文献   

Seismological features of island arc crust as inferred from recent seismic expeditions in Japan     

Takaya Iwasaki  Toshikatsu Yoshii  Tanio Ito  Hiroshi Sato  Naoshi Hirata 《Tectonophysics》2002,355(1-4)

Crustal studies within the Japanese islands have provided important constraints on the physical properties and deformation styles of the island arc crust. The upper crust in the Japanese islands has a significant heterogeneity characterized by large velocity variation (5.5–6.1 km/s) and high seismic attenuation (Qp=100–400 for 5–15 Hz). The lateral velocity change sometimes occurs at major tectonic lines. In many cases of recent refraction/wide-angle reflection profiles, a “middle crust” with a velocity of 6.2–6.5 km/s is found in a depth range of 5–15 km. Most shallow microearthquakes are concentrated in the upper/middle crust. The velocity in the lower crust is estimated to be 6.6–7.0 km/s. The lower crust often involves a highly reflective zone with less seismicity, indicating its ductile rheology. The uppermost mantle is characterized by a low Pn velocity of 7.5–7.9 km/s. Several observations on PmP phase indicate that the Moho is not a sharp boundary with a distinct velocity contrast, but forms a transition zone from the upper mantle to the lower crust. Recent seismic reflection experiments revealed ongoing crustal deformations within the Japanese islands. A clear image of crustal delamination obtained for an arc–arc collision zone in central Hokkaido provides an important key for the evolution process from island arc to more felsic continental crust. In northern Honshu, a major fault system with listric geometry, which was formed by Miocene back arc spreading, was successfully mapped down to 12–15 km.  相似文献   

南极中山站午后极光强度与太阳风参数的关系          下载免费PDF全文

胡红桥  刘瑞源  杨惠根  王敬芳  Natsuo Sato  Masayu kiKikuchi  李升贵 《极地研究》2001,13(3):151-158

本文利用1997年和1998年南极中山站多通道扫描光度计的地面观测数据和WIND卫星在弓激波上游对太阳风参数的观测数据，对午后高纬极光强度与太阳风等离子体密度、动压以及太阳风速度之间的相关性进行了定量研究。研究表明，午后极光630．0nm的强度与太阳风等离子体参数之间有较好的相关，630．0nm的强度表现出随太阳风等离子体密度、动压和速度的增大而增加的趋势，其相关系数分别为0．84、0．88和0．61；而557．7nm极光的强度与太阳风等离子体参数之间的相关较差。午后557．7nm极光的强度与太阳风等离子体参数之间的相关较差。午后557．7nm和630．0nm对太阳风参数的不同响应表明太阳风对630．0nm影响更直接，而557．7nm受到了磁层动力学过程的影响。  相似文献