Structure of the strong tidal jet in the naruto strait     

Yoshio Takasugi  Tateki Fujiwara  Takehiko Higo 《Journal of Oceanography》1990,46(3):69-83

In order to clarify the structure of the strong tidal current at the Naruto Strait in the Seto Inland Sea of Japan, the sea-level values were observed in the strait and the current measurements were made with an Acoustic Doppler Current Profiler (ADCP).The tidal volume transports for M₂ and S₂ tides were about 74×10³ and 26×10³ m³ sec^–1, respectively. The horizontal profile of the velocity at the phase of the strong tidal current compares favorably with a theoretical profile of the two-dimensional steady turbulent jet except for the side parts of the profile. Moreover, the entrainment rate of the surrounding water into the strong tidal jet was estimated from the difference of mass flux between two cross-sections at the strait, the entrainment rate and entrainment constant for both the northward and southward flows being about 1.3–2.5×10^–4m^–1 and about 0.03–0.05, respectively.  相似文献   

The partition of minor transition metals between manganese oxides and seawater     

Noburu Takematsu  Yoshio Sato  Shiro Okabe 《Journal of Oceanography》1981,37(4):193-197

The behavior of transition metals (Co, Ni, Cu and Zn) on precipitation of manganese oxides from seawater pumped up from a well at the site of the Marine Science Museum, Tokai University, and collected from several tanks along the water supply system to an aquarium was investigated. The distribution coefficients of cobalt and nickel between manganese oxides and seawater were different at different sampling points along the water supply system. At sampling points with high rates of manganese oxide precipitation, the distribution coefficients were about one order of magnitude smaller than those at the points with low precipitation rates, while there were no remarkable differences in the distribution coefficients of copper and zinc among the sampling points. The distribution coefficients of minor transition metals, with the exception of copper, observed at the points with low precipitation rates were comparable to those measured experimentally using manganese dioxides.  相似文献   

The rate of oxidation of ferrous iron in seawater and the partition of elements between iron oxides and seawater     

Yoshio Sato 《Journal of Oceanography》1989,45(4):270-278

At the Minamichita Beach Land (Mihama-cho, Aichi, Japan), seawater is pumped up from underground and is supplied to aquaria. The underground seawater containsca. 2 ppm of Fe (II), 0.1 ppm of Mn (II) and a little dissolved oxygen. Iron oxide is formed in the seawater when aerated. The oxidation rate of Fe (II) was measured to be 1.4×10¹⁴ mol^–3 l ³ min^–1, which is comparable to the lowest values in the literature. The slow rate of Fe (II) oxidation obtained here can be attributed to the presence of organically bound iron in the seawater. The distribution coefficient of cations between seawater and iron oxide phase was in the order of Cu>Ni>Co>Cd>Mn, which is consistent with that predicted from their hydrolysis constants. The adsorption affinity sequence of oxyanions was phosphate >vanadate> molybdate. The difference in phosphate from the prediction of the adsorption theory was attributed to the formation of ferriphosphate on the oxide surface. On the basis of these data, the limitation and usefulness in the application of the distribution coefficients to marine environments were discussed.  相似文献   

Errors in sampling procedure for the determination of dissolved oxygen by Winkler method     

Yoshio Horibe  Yukio Kodama  Koji Shigehara 《Journal of Oceanography》1972,28(5):203-206

Sources of systematic error in the sampling procedure by Winkler method were examined. In the laboratory experiment, the dissolution of atmospheric oxygen into oxygenfree sea water during sampling amounts to 0.022 ml/l, and the effect of dissolved oxygen in sea water remaining in oxygen bottle is 0.019 ml/l. The effect of reagents added amounts to 0.017 ml/l. In the sampling procedures aboard, the effect of dissolution became bigger, and the table is presented for the correction to the reported value of dissolved oxygen measured by the “Manual of Oceanographic Observation”. The corrected value of dissolved oxygen in the routine analysis may not be correct within 0.02 ml/l.  相似文献   

On the free oscillation of water in a circular lake with paraboloidal base,III     

Yoshio Shibaoka  Kenji Oto 《Journal of Oceanography》1970,26(2):108-109

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Perturbations by the oblateness of the Earth and by the planets in the motion of the Moon     

Yoshio Kubo 《Celestial Mechanics and Dynamical Astronomy》1982,26(1):97-112

Perturbations in the motion of the Moon are computed for the effect by the oblateness of the Earth and for the indirect effect of planets. Based on Delaunay's analytical solution of the main problem, the computations are performed by a method of Fourier series operation. The effect of the oblateness of the Earth is obtained to the second order, partly adopting an analytical evaluation. Both in longitude and latitude are found a few terms whose coefficient differs from the current lunar ephemeris based on Brown's theory by about 0.01. While, concerning the indirect effect of planets, several periodic terms in the current ephemeris seem to have errors reaching 0.05.As for the secular variations of and due to the figure of the Earth and the indirect effect of planets, the newly-computed values agree within 1/cy with Brown's results reduced to the same values of the parameters. Further, the accelerations in the mean longitude, and caused by the secular changes in the eccentricity of the Earth's orbite and in the obliquity of the ecliptic are obtained. The comparison with Brown shows an agreement within 0.3/cy² for the former cause and 0.02/cy² for the latter. An error is found in the argument of the principal term for the perturbations due to the ecliptic motion in the current ephemeris.Proceedings of the Conference on Analytical Methods and Ephemerides: Theory and Observations of the Moon and Planets. Facultés universitaires Notre Dame de la Paix, Namur, Belgium, 28–31 July, 1980.  相似文献   

Incorporation of U,Pb and Rare Earth Elements in Calcite through Crystallisation from Amorphous Calcium Carbonate: Simple Preparation of Reference Materials for Microanalysis     

Yusuke Miyajima  Ayaka Saito  Hiroyuki Kagi  Tatsunori Yokoyama  Yoshio Takahashi  Takafumi Hirata 《Geostandards and Geoanalytical Research》2021,45(1):189-205

Uncertainty for elemental and isotopic measurements in calcite by LA‐ICP‐MS is largely controlled by the homogeneity of the reference materials (RMs) used for calibration and validation. In order to produce calcite RMs with homogeneous elemental and isotopic compositions, we incorporated elements including U, Pb and rare earth elements into calcite through heat‐ and pressure‐induced crystallisation from amorphous calcium carbonate that was precipitated from element‐doped reagent solution. X‐ray absorption spectra showed that U was present as U(VI) in the synthesised calcite, probably with a different local structure from that of aqueous uranyl ions. The uptake rate of U by our calcite was higher in comparison with synthetic calcite of previous studies. Variations of element mass fractions in the calcite were better than 12% 2RSD, mostly within 7%. The ²⁰⁷Pb/²⁰⁶Pb ratio in the calcite showed < 1% variations, while the ²³⁸U/²⁰⁶Pb ratio showed 3–24% variations depending on element mass fractions. Using the synthetic calcite as primary RMs, we could date a natural calcite RM, WC‐1, with analytical uncertainty as low as < 3%. The method presented can be useful to produce calcite with controlled and homogeneous element mass fractions and is a promising alternative to natural calcite RMs for U‐Pb geochronology.  相似文献   

Supercooled drizzle formed by condensation–coalescence in the mid-winter season of the Canadian Arctic     

Masahiro Kajikawa  Katsuhiro Kikuchi  Yoshio Asuma  Yusuke Inoue  Noboru Sato 《Atmospheric Research》2000,52(4):377

Supercooled drizzle (freezing drizzle) was observed at Inuvik, N.W.T., Canada (68°22′N, 133°42′W) on December 20, 21 and 27, 1995. Meteorological conditions in which the supercooled drizzle could form under low temperatures (colder than −20°C) in the mid-winter season of the Canadian Arctic were examined from the sounding data and data measured by a passive microwave radiometer at ground level. The following results were obtained. (1) Supercooled drizzle fell to the ground with ice pellets and frozen drops on snow crystals. (2) The maximum size of supercooled drizzle particles increased as the depth of cloud layer saturated with respect to water increased. (3) Because a layer of air temperature higher than 0°C was not detected from the sounding data at Inuvik, melting of snow particles was impossible. It was concluded, therefore, that supercooled drizzle was formed by the condensation–coalescence process below freezing temperature.  相似文献   

Incessant excitation of the Earth's free oscillations: global comparison of superconducting gravimeter records     

Kazunari Nawa  Naoki Suda  Yoshio Fukao  Tadahiro Sato  Yoshiaki Tamura  Kazuo Shibuya  Herbert McQueen  Heikki Virtanen  Jussi Kriinen 《Physics of the Earth and Planetary Interiors》2000,120(4):289-297

Records of superconducting gravimeters (SGs) at Canberra (Australia), Esashi (Japan), Metsähovi (Finland) and Syowa Stations (Antarctica) were analyzed to search for further evidence of background free oscillations of the Earth. Spectrograms for 1-year period and averaged power spectra for seismically quiet periods were obtained for each of the stations. Anomalous features of the oscillations observed at Syowa Station, such as an apparent seasonal variation and a high intensity at frequencies between 3 and 4 mHz, were absent at the other SG stations. Among the SG stations used in this study, the background free oscillations were detected most consistently and distinctly at Canberra, where the noise level was comparable to that at the IDA quietest station, while that at Syowa Station was close to the critical limit for detecting the oscillations. The background free oscillations provide a good reference to evaluate the noise level in the milliHertz band.  相似文献   

Postglacial anthropogenic fires related to cultural changes in central Japan,inferred from sedimentary charcoal records spanning glacial–interglacial cycles     

Jun Inoue  Chikako Okuyama  Ryoma Hayashi  Yoshio Inouchi 《第四纪科学杂志》2021,36(4):628-637

We examined long-term charcoal records spanning the glacial–interglacial cycles that are evident in two cores collected from Lake Biwa in central Japan. We found that the records of the two cores have a similar long-term variation pattern of charcoal concentrations and abundant large charcoal fragments in postglacial sediments, which indicates that frequent fires occurred near the shores of Lake Biwa during the postglacial period. Analogous natural conditions in the early postglacial period and the early part of the last interglacial period strongly suggest that the frequent fires that occurred only during the postglacial period were anthropogenic. A comparison between the charcoal records of Lake Biwa sediments and the cultural changes and human populations in this district suggests that anthropogenic fires in this district were influenced by the lifestyle and culture of each era rather than by the populations. Humans tended to use more fire at the start of the settlement during the early Neolithic era in this region, in spite of the small population size.  相似文献