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91.
Strontium concentrations and strontium-chlorinity ratios in sea water of the North Pacific and the adjacent seas of Japan 总被引:1,自引:0,他引:1
Strontium contents of 232 sea water samples collected at various stations in the North Pacific and adjacent seas of Japan were measured by the atomic absorption spectrophotometry and strontium-chlorinity ratios were determined. Mean Sr concentration is 8.08 mg/kg and mean Sr/Cl ratio is 0.425 mg/kg/Contrary to some recent reports, regional and vertical variations of Sr/Cl ratios were statistically insignificant, and presence of particulate strontium was not confirmed. 相似文献
92.
Yoshiyuki Nakano Hideshi Kimoto Shuichi Watanabe Koh Harada Yutaka W. Watanabe 《Journal of Oceanography》2006,62(1):71-81
We have developed new systems capable of profiling to >1000 m for measuring in situ pH and fugacity of CO2 (fCO2) in the ocean using spectrophotometric analysis (pH and CO2 profilers). The in situ pH is determined by detecting the color change of the pH indicator (m-cresol purple). It can withstand ambient pressure to 1000 m depth. The CO2 profiler analyzed in situ fCO2 by detecting the change of pH in an inner solution, equilibrated with the seawater through a gas permeable membrane. It can
be operated to 2500 m depth. We used an amorphous fluoropolymer tubing form of AF-2400 for the gas permeable membrane due
to its high gas permeability coefficients. The inner solution was a mixture of 2 μM bromocresol purple (BCP) and 5 μM sodium
hydroxide. This system gave us a response time of 1 minute, which is twice as fast as previous systems. The precisions of
pH and CO2 profilers were within 0.002 and 2.5% respectively. We have used these profilers to study the North Pacific, obtaining good
agreement with the difference between the data from profilers and a discrete bottle of 0.002 ± 0.005 pH (SE, n = 25) and −0.4
± 3 μatm (SE, n = 31). 相似文献
93.
Index species of zooplankton of the Oyashio water are found in and beneath the salinity minimum layer in Sagami Bay. In order to clarify the intrusion path of the intermediate Oyashio Water (or the water of the Mixed Water Region), the oceanographic conditions off the Boso Peninsula are studied by using available hydrographic data obtained mainly by Japan Meteorological Agency. The cross-sectional salinity distribution along KJ line which extends southeastward from off the tip of the peninsula always indicates the existence of a low salinity patch just off the coast in the salinity minimum layer. This water is well separated from the offshore low salinity water which is considered as the water in the western margin of the so-called North Pacific Intermediate Water. We refer to the former water as the coastal salinity-minimum-layer (SML) water and to the latter as the offshore SML water. The coastal SML water is usually bounded by the current zone of the Kuroshio. The existence of the coastal SML water seems to indicate the possible pathway of the intermediate Oyashio water along the Boso Peninsula into Sagami Bay. The detailed water type analysis is made in T-S plane, S-st plane, and O2-st plane. There is no significant difference in distribution ranges of the water types between the coastal SML water and the offshore SML water. However, the water types of the coastal SML water is not uniformly distributed, and the water can be classified into two groups: group A with relatively high oxygen content and relatively low salinity value and group B with relatively low oxygen content and relatively high salinity value. Group A is thought to be associated with strong event-like intrusions, the details of which will be discussed in Part II. 相似文献
94.
Abundances and biomasses of planktonic ciliates and copepod nauplii, major components of the microzooplankton community, were investigated in the subarctic North Pacific and the Bering Sea in summer of 1997. Their regional variation was illustrated by demarcating the entire area into five regions. Ciliates always predominated both in abundance (>94%) and biomass (>78%) over nauplii. Regional means of ciliates in the water column were higher in the Alaskan Gyre (120 × 106 cells/m2) and the Western Subarctic Gyre (110 × 106 cells/m2) in terms of abundance, and rich in the Bering Sea Gyre (360 mgC/m2) and the Western Subarctic Gyre (340 mgC/m2) in terms of biomass. By contrast, standing crops of ciliates were poor in the Oyashio Region (67 × 106 cells/m2; 170 mgC/m2) and the Transition Region (64 × 106 cells/m2; 160 mgC/m2). The values of biomass reported here are generally in agreement with the values reported previously from the Bering Sea Gyre and the Alaskan Gyre but are considerably higher than the previous value found in the Western Subarctic Gyre. No significant correlations could be found between chlorophyll a crop and standing crops of ciliates and copepod nauplii over the entire subarctic North Pacific and the Bering Sea during this summer. 相似文献
95.
The behavior of low density fresh water injected at the surface of a uniformly rotating saline water was investigated on the basis of a tank experiment. The injected water mass shows a clockwise circulation and grows gradually with an axisymmetric convex shape, until it breaks into two vortices at a critical size. An experimental formula for the change of radius of the water mass with time for the axisymmetric stage is obtained. It is shown that within our experimental range of values the radius of the water mass increases almost in proportion tot 1/2, wheret is the elapse time, while the inviscid theory indicates that the radius should increase in proportion tot 1/4. The dependence of the radius on elapse time is essential for forecasting the extent of discharged waters. The position of the maximum azimuthal velocity is fixed at \(V = - ge^{ - a^2 q^2 } \) within our experimental range of values wherer is the radial coordinate,f the Coriolis parameter,v the viscosity coefficient andQ the flow rate of injection, respectively. This radius corresponds to the radial scale derived by Gillet al. (1979). The steadiness of the position of the maximum azimuthal velocity may be essential in partition of the water mass into inner and outer regions and in the understanding the derived experimental formula. The critical radius for breaking is also investigated. The radius is shown to be independent ofQ and to be almost proportional to (Δ ρ / ρ )1/2 f -1 whereρ is the density of the saline water andΔρ the density difference between the saline and injected waters. Even after the water supply is cut off in the axisymmetric stage, the radius of the water mass increases at almost the same rate as before, while its thickness decreases. The behavior after supply cut-off is discussed in the Appendix. 相似文献
96.
Yutaka Nagata 《Journal of Oceanography》1979,35(1):26-35
The nature of the autocovariance function and power spectrum of time series of spike-array type is discussed. As the spacing of spikes is not easily seen directly in power spectrum, prudence should be exercised in interpreting the gradient spectrum of oceanic fine-structure. We calculated the autocovariance function and lag joint probability density of the record of the vertical profile of the vertical temperature gradient measured in the San Diego Trough. The results obtained support the results of the bispectral analysis in the previous paper (Nagata, 1978) that the predominant length scale of about 5 m has two meanings: spacing of the spikes and wavelength of a sinusoidal wave. The results seem to show the existence of nernal waves having a vertical wavelength the same as the spacing of the spikes or the thickness of the homogeneous layer in the oceanic fine-structure. 相似文献
97.
Tomoharu?SenjyuEmail author Yutaka?Isoda Takafumi?Aramaki Shigeyoshi?Otosaka Shinzo?Fujio Daigo?Yanagimoto Takashi?Suzuki Kenshi?Kuma Kosuke?Mori 《Journal of Oceanography》2005,61(6):1047-1058
Hydrographic observations have revealed detailed structure of the Bottom Water in the Japan Sea. The Yamato Basin Bottom Water
(YBBW) exhibits higher temperatures and lower dissolved oxygen concentrations than those found in the Japan Basin Bottom Water
(JBBW). Both Bottom Waters meet around the boundary region between the Yamato and the Japan Basins, forming a clear benthic
front. The structure of the benthic front suggests an estuary-like water exchange between both Basins, with the inflow from
the Japan Basin passing under the outflow from the Yamato Basin. It is inferred from the property distributions that the JBBW
flowing into the Yamato Basin is entrained by the cyclonic circulation in the basin, and modified to become the YBBW. Vertical
diffusion and thermal balance in the YBBW are examined using a box model. The results show that the effect of geothermal heating
has about 70% of the magnitude of the vertical thermal diffusion and both terms cancel the advection term of the cold JBBW
from the Japan Basin. The box model also estimates the turnover time and vertical diffusivity for the YBBW as 9.1 years and
3.4 × 10−3 m2s− 1, respectively. 相似文献
98.
Stokes' expansion is applied to the internal waves of finite amplitude, which propagate on the interface between two layers of infinite thickness. Stream function, wave profile, phase velocity and mass transport velocity are given in the fifth order approximation. It is shown that (a) phase velocity increases with increase of wave steepness, (b) mass transport appears in the direction of the wave propagation in both layers as in the case of the surface waves, and (c) when the density difference is very small, the wave profile is flattened not only at the troughs but also at the crests. 相似文献
99.
The behavior of the water wedge advancing along the interface between two homogeneous layers is investigated experimentally. The horizontally intruding wedge is strongly influenced by the detailed structure of the interface, even when the interface is sharp enough for its position to be visually determined. Within our experimental range, the intrusion velocity is very slow and depends on the thickness of the interface along which the water wedge intrudes. The wedge length is well described by the relation which is derived using an analogy to the linearly stratified case. The results could be useful for understanding the generation mechanism of the oceanic microstructure. 相似文献
100.
239, 240Pu,137Cs and90Sr concentrations were determined in sea waters from the central and western North Pacific in 1980 and 1982. The results are
consistent with those reported earlier for North Pacific waters. The profiles of90Sr and137Cs show a monotonic decrease with depth, whilst239, 240Pu shows a distinct subsurface maximum at a depth between 400 and 1,000 m.
The calculated inventories of these nuclides significantly exceed the global mean fallout inputs for these latitudes. This
may be due to local fallout input to the ocean at times of large-scale nuclear weapon tests in the equatorial North Pacific.
The existence of measurable amounts of137Cs and239, 240Pu in deep waters suggests that these nuclides are transported by sinking particulate matter from the surface to the deep
ocean. 相似文献