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1.
Diatomaceous silica, pretreated at various temperatures between 125 and 900C, was subjected to dissolution experiments and was analyzed using X-ray diffraction and infrared spectra. The diatomaceous silica preheated up to 900C, dissolved throughly into the solution of 2 per cent Na2CO3. On the digestion in the solution of 2 per cent Na2SO4, the dissolution of the silica decreased as the pretreating temperature increase; the degree of dissolution was different for various species. According to infrared absorption studies, the diatomaceous silica pretreated at a temperature below 500C preserved the reversibility of dehydration-rehydration almost qualitatively, while heating above 500C the samples lost the reversibility. Deformation of some kinks of diatomaceous silica pretreated above 500C, was percepted on infrared absorption spectra around 1,150 cm–1. The samples pretreated up to 900 C, however, did not show such an internal structural change as could be identified by the X-ray diffraction analysis. The content of Al and Fe in diatomaceous silica was low and have not much difference in quality among diatom species. From these experimental results, it was adequately understandable that diatomaceous silica, which has a metastable character, is variable in the silica forms among species and its process and rate of transformation of internal structure and/or surface sites by the treatment at given temperatures also show differences.  相似文献   

2.
Transmission and reflection problems when kissing≓ occurs among planetary and topographic Rossby waves in a two-layer ocean are studied. The slope parameterS(=dh 2/dx, whereh 2is the thickness of the lower layer) is assumed to have constant values in the regionsx 0 andxL and to vary linearly with the increase ofx in the region0xL (refer to Fig. 2 in the text). Furthermore, a wave is entered fromx=– and kissing is assumed to occur in the region (0<)x axxb(<L).It is found that a wave of the same type as the incident wave is mainly transmitted when the width of the region in which kissing occurs,L kiss(=tx b–xa), is smaller than kiss=2/(¦K¦+ y/2), whereK is a representative wavenumber in the regionx ab, y is they-component of , and is the frequency. WhenL kiss is larger than kiss, on the other hand, the main wave transmitted is of a different type to the incident wave. As an application, transmission and reflection problems of planetary Rossby waves are considered, and it is shown that when an external (internal) planetary Rossby wave is entered, an internal (external) one can be transmitted due to the effect of kissing.  相似文献   

3.
Two independent methods of paleobathymetry, applicable to hydrocarbon-derived carbonates, are explored in this study. The oxygen isotope method exploits the temperature decline with depth that leaves a measurable imprint on the 18O composition of pristine products of venting comprised of aragonites and dolomites. The other method makes use of the bathymetric preferences of benthic foraminiferal taxa entrapped in the carbonate buildups. These two methods were tested on the calcari aLucina limestones hosted in turbidites and mudstones infilling the Miocene-age Marnoso-arenacea basin. The limestone blocks, rich in fossils of chemosymbiotic-like fauna, preserve a 10-Ma record of hydrocarbon venting from Langhian to lower Messinian times. Our results indicate that carbonate accretion and lithification occurred at upper bathyal depths in waters not shallower than 200–250 m. The 18O of venting products contains the imprints of profound hydrographic changes that occurred in the ancient Mediterranean basin from the lower Serravallian to the lower Messinian.  相似文献   

4.
Numerical solutions are examined for isolated, intense vortices as influenced by western bounding bottom topography through the use of a rigid-lid, two-layer primitive -plane numerical model. Systematic studies are made of the sense of rotation (cyclonic/anticyclonic), the consequence of varying the gradient of bottom slope, and the different vertical shear in a two layer ocean. In the basin with a bottom slope, the nearly barotropic anticyclonic vortex forms a modon-like vortex for S with fixedRo 2<O(1) (where is the ratio between the variation of the Coriolis parameter across the eddy to the Coriolis parameter in the center, S the topographic effect and,Ro 2 the Rossby number in the lower layer) and its generation is due to a compound effect of the planetary beta, topographic beta, avvection, and mirror image. The formation of the modon-like vortex and the propagation of the original vortex onto the bottom slope depends on the strength of slope gradient and the baroclinicity of the vortex. The nearly barotropic anticyclonic vortex evolves into the stronger upper ocean one with increasing S: the gradient of the bottom slope becomes steeper. Then the original vortex lives longer because the barotropic component of the energy is converted to the baroclinic one and it moves toward southeast in forming a modon-like vortex in the lower layer. The evolution of a vortex in the model results are compared to observational results of a Kuroshio warm core ring (KWCR) obtained from hydrographic data (June, 1985) and from NOAA satellite infrared images (April, 1985 to July, 1985). It is shown that a KWCR (June, 1985) is influenced by the western continental slope/shelf of the East Japan.  相似文献   

5.
We analyze the data of investigation of the intrusive structure of the Gulf-Stream frontal zone obtained in making frequent drift sections with the help of an MGI-8102 probing complex, study the regularities of variation of temperature, salinity, and density along separate intrusions, and present a series of results connected with the specific features of initiation and development of intrusions and the types of exchange processes determining their transformations. It is shown that the T-diagrams of all intrusions are well separated into segments with different slopes. Moreover, by comparing the slopes and locations of these segments with each other and with the T-diagrams of the Gulf Stream and slope waters, we can fairly reliably attribute the corresponding segments of intrusions to one of the following four types: initial dynamic folds of the frontal zone, layers of domestic water separating the intrusive segments of foreign water from each other, intrusive segments characterized by the penetration of ambient water, and segments not intrusive initially but getting the required slope as a result of interaction with upper and lower intrusive segments. For segments of the last two types, it is possible to specify the predominant type of exchange.  相似文献   

6.
The downward short- and long-wave radiation fluxes at the sea surface (S, L) were measured aboard the R/VHakuho Maru, University of Tokyo, for the period of 117 days on six cruises from 1981 to 1985 in the western North Pacific near Japan. The upward fluxes of short- and long-wave radiation (S, L) were calculated by Payne's (1972) table and the Stefan-Boltzmann's law, respectively. The sensible and laten heat fluxes (Q h ,Q e ) were also estimated from an aerodynamic bulk method.From April to August, the daily mean value ofS varied with the amplitude of 100200 Wm–2. The value ofS was estimated approximately 6% ofS in all seasons. The difference betweenL andL was so small that the net radiation flux (Q n ) was dominated byS. In addition, the net heat flux at the sea surface was also dominated byS due to small values ofQ h andQ e , and then the ocean was warmed at the rate of 111 Wm–2 in April and 63 Wm–2 in August in the Oyashio Area, and 132 Wm–2 in May and 164 Wm–2 in June in the Kuroshio Area, respectively.From September to March, a remarkable negative correlation between the day to day variation ofS and that ofL was observed except when an intense cold air outbreak occurred. It was found that the correlation was caused by the cloud climatological feature of the western North Pacific in this period.S was not a dominant factor in the net heat flux. The value ofQ h +Q e in the Kuroshio Area ranged from 260 Wm–2 to 630 Wm–2, much larger thanQ n which ranged from –8 Wm–2 to 92 Wm–2 in the leg mean values (each leg period was about 10 days). Then the ocean was cooled at the rate of –160–620 Wm–2 during this period. The net heat flux in the Kuroshio Area averaged over five legs from late November to February was –473 Wm–2. This value is 50100% larger than the climatological values reported so far.The temporal and spatial variability of radiation fluxes and heat fluxes during each leg was also discussed.  相似文献   

7.
The relationship between Cd and PO4 in the Kuroshio and Oyashio regions and the Okhotsk Sea was examined. The resultant equations are as follows: Cd (ng l–1)=37.0 PO4 (M)+2.6; Cd(ng l–1)=32.1 PO4 (M)+1.2 and Cd (ng l–1)=34.1 PO4 (M)+7.9, respectively. These results are in good agreement with previously reported studies, and indicate that during removal from surface waters to deeper waters by biological assimilation and regeneration in deeper waters Cd and PO4 maintain the same ratio in the open ocean. The relationship between Cd and PO4 in coastal waters, however, differed from that in the open ocean.  相似文献   

8.
The nonlinear modulation of water wave groups is investigated and the interaction equations with induced flows are obtained. The analysis is performed up to the third order of the wave steepness a by treating it as a small parameter in the singular perturbation technique by means of the Krylov-Bogoliubov-Mitropolski method. The equation which governs the development of the wave envelope is found by a modification of the ordinary nonlinear Schroedinger equation for the case of uniform depth. The equations governing the behavior of the induced mean flow are examined by deriving the second order flow when the form of the modulated wave train is prescribed. The present theory can describe the mean flow caused by the radiation stress. Some applications containing the monochromatic wave instability are given to confirm the theoretical results.An outline of this paper was presented at The Ocean Surface Symposium (Sendai, 1984).  相似文献   

9.
The values of the function (T, S) on theT, S straight lines with different angular coefficients have been analysed. It is shown that at the point of contact of theT, S straight lines with the corresponding isopycnals, has a conventional maximum and the density ratio isR=1. It is inferred that a conventional density maximum may occur and that theT, S gradients are compensated at the oceanic fronts separating the sub-arctic and subtropical water structures.Translated by Vladimir A. Puchkin.  相似文献   

10.
The mechanism of the development of wind-waves will be proposed on the basis of the observed wave spectra in the wind tunnels and at Lake Biwa (Imasato, 1976). It consists of two aspects: One is that the air flow over the wind-waves transfers momentum concentratively to the steepest component waves and the other is that the upper limit of the growth of a wave spectral density is given by the ultimate value in the slope spectral density. The first aspect means that the wave field has the momentum transfer filter on receiving the momentum from the air flow. Wind-waves in the stage of sea-waves receive the necessary amount of momentum by the form drag,e.g. according to the Miles' (1960) inviscid mechanism, through a very narrow frequency region around a dominant spectral peak. On the other hand, wind-waves in the stage of initial-wavelets receive it according to the Miles' (1962a) viscous model through a fairly broad frequency region around the peak. The upper limit ofS max developing according to viscous mechanism is given byS max =6.40×10–4 k max –2cm2s andS max =2.03C(f max )–2cm2s(S max is the power density of the wave spectral peak with the frequencyf max ,k max is the wave number corresponding to the frequencyf max andC is the phase velocity).From the second aspect, the upper limit of the growth of wave spectral density is given by 33.3f –4cm2s in the frequency region of late stage of sea-waves. Therefore, the spectral peak, which has the largest value in the slope spectral density in the component waves of the wave spectrum, rises high over the line 4.15f –5cm2s. The energy is transported from the spectral peak to the high frequency part and to the forward face of a wave spectrum by nonlinear wave-wave interaction. This nonlinearity is confirmed by the bispectra calculated from the observed wind-wave data. In the stage of sea-waves, nonlinear rearrangement of the wave energy comes from a narrow momentum transfer filter, and, in the stage of initial-wavelets, it comes mainly from small corrugations and small steepness of the wave field.  相似文献   

11.
Over 20 occurrences of discontinuous limestone blocks, locally called calcari aLucina, were mapped in the Tuscan—Romagna region of the northern Italian Apennines. The limestones, consisting of a variable mixture of authigenic carbonates (calcite, dolomite, and aragonite), sulfides (primarily pyrite), and allogenic silicates, occur in association with turbidite and hemipelagite units that were deposited in foredeep basins during early to late Miocene times. The limestone blocks are interpreted to represent relicts of carbonate buildups formed around methane-rich fluid vents on the basis of their (1) striking petrographic similarities to carbonates from cold vents in the modern oceans; (2) unique chemosynthetic-like fauna, and (3) anomalously negative 13C values ( 13C = – 16 to – 58 PDB). The contemporaneous tectonism of the Apennine orogeny is likely to be the primary cause for the expulsion of the methane-rich fluids to the seabed in a manner analogous to the fluid-flow processes occurring at modern accretionary prisms.  相似文献   

12.
Bispectral analysis is applied to records of the vertical profile of the vertical temperature gradient in the oceanic thermocline in the San Diego Trough. The bispectra exhibit three notable features; (1) bispectral peaks at the points (0.2 m–1, 0.2 m–1) and (0.2 m–1, 0.1 m–1), (2) bispectral ridges along the lines ( 1= 0, 2= 0 and 1+ 2= 0 corresponding to peak wavenumbers 0 in power spectra, and (3) array of bispectral peaks of interval of 0.2 m–1 The results are compared with the bispectra of several modeled time series of spike-array type. The periodicity of 5 m found in the records seems to have two meanings: spacing of predominant spikes and wavelength of predominant sinusoidal wave. If this indicates the existence of internal waves having a vertical wavelength the same as the scale of homogeneous layers, it would suggest the possible importance of internal waves in the formation and maintenance mechanisms of oceanic microstructure.  相似文献   

13.
Analysis is made of wind and wave data, which were obtained during the passage of Typhoon 8013 at an Ocean Data Buoy Station south of Honshu operated by the Japan Meteorological Agency, in order to investigate the wave dependence of sea-surface roughness parameter in the situation where wind waves are dominant with less significant swells. The data fit better the wave-dependent expression of the wind stress,z 0 p/u*=, than to Charnock's formula,gz 0/u*2=, wherez 0 is the roughness length, p the angular frequency of the spectral peak of wind waves,u* the friction velocity of air,g the acceleration of gravity, and are non-dimensional constants. The results are very similar to those of our previous study using data from an oil producing platform in the Bass Strait, Australia, although the type of observation system and the synoptic situation of the winds and wind waves were totally different.  相似文献   

14.
The development process of wind-waves of which spectral peak distributes from 0.6 cps to 9.3 cps will be discussed on the basis of the wind tunnel experiments and of the field observations performed at Lake Biwa. The characteristics of power and slope spectra are here presented. The development process of these wind-waves is characterized by three stages;i.e. initial-wavelets, transition stage and sea-waves. In the wind tunnel experiments, the transition from the stage of the initial-wavelets to the transition stage occurs when the wave spectral peak arrives at the line 6.40×10–4 k –2cm2·sec (wherek is wave number) or when the slope spectral density at the frequencyf max becomes larger than 6.40×10–4 sec. In the stage of sea-waves, the component wave of a wave-spectral peak is steepest in the component waves. And the wave spectral peak develops along the line 1.02×102 f –6 cm2·sec (wheref is the frequency corresponding to the wave numberk) untill it reaches the line 33.3f –4cm2·sec, and thereafter develops along the latter line, which indicates the constant density of slope spectrum. It is suggested that the nonlinearity of wind-waves must become stronger as wind-waves develop. The effective momentum flux ws from the air flow to wind-waves in this stage is evaluated to be about 49% of the total stress 0.  相似文献   

15.
We analyzed hydrographic data obtained monthly by the Iwate Prefectural Fisheries Laboratory during 1977–1981. Our attention was focussed on the classification of waters based on the Temperature-Salinity (T-S) scatter diagram analyses, and on the extraction of the mean state of their distribution for each season. The water system was defined as all waters occupying some specific region on the T-S plane, and the mean state for each season was expressed by the distribution of the mode water systems (i.e., the most commonly occuring water system).Because of the coexistence of the Tsugaru Warm Current, the Oyashio and the Kuroshio, and their large seasonal variability, the sea waters had a wide variety of T-S combinations. The detailed T-S scatter diagram analyses allowed us to classify the waters into six water systems. A time-longitude diagram of water systems and the distribution of mode water systems are presented. The latter showed clear seasonal variations of the Tsugaru Warm Current and the Oyashio.Though the water system analysis was successfully able to present the distribution of the various waters in the Sanriku Coastal Area and to clearly extract the mean state of sea conditions, it was found that the classification of water systems on the T-S plane was not complete in all cases for this area.  相似文献   

16.
Stability constants were determined for60Co (II)-amino acid complexes in sodium perchlorate media at an ionic strength=0.67, using cation exchange resins. Stability constants were, for Co(II)-phenylalanine, log 1=4.4, log 2=8.2, log 3=11.7, for Co(II)-histidine, log 1=7.4. for Co(II)-valine, log 1=4.3, log 2=8.5, for Co(II)-proline, log 1=4.1, and for Co(II)-tyrosine, log 1=7.2, respectively. The abundance of Co(II)-amino acid complexes in seawater was calculated from these stability constants on the basis of chemical equilibrium, assuming the concentration of individual amino acid to be 10–7 to 10–8 mol l–1. It was inferred that the Co(II)-amino acid complexes are probably not formed abundantly in seawater while inorganic species of60Co(II) may still be dominant for a short period of time after discharge into seawater as liquid waste.  相似文献   

17.
Current path records of the Kuroshio off southern Japan have been examined for the period 1960–1977. Together with previously published results (S.Yoshida, 1961;Shoji, 1972) this evidence indicates that all major changes in the path of the Kuroshio off Cape Shiono were preceded by the formation of a small trigger meander off Kyushu and its downstream propagation to Cape Shiono. The periods of occurrence of these trigger meanders, most of which decay without propagating downstream, are documented. Small meanders off Kyushu occur throughout the year, but all of those which triggered changes off Cape Shiono were initially generated in the period January–April.Contribution No. 4 of the Pacific International Research Association.  相似文献   

18.
The selectivity of amino acid assimilation by marine bacteria was examined using seven kinds of14C-amino acids and the acid hydrolysate of14C-labelled proteins. It was found that the net assimilation and respiration by marine bacteria followed MICHAELIS-MENTEN kinetics for all of amino acids used in our experiments. Maximum velocities of amino acids were 0.01 to 0.19g carbon/hour per 2×107 cells for net assimilation and less than 0.18g carbon/hour per 2×107 cells for respiration at 20C. The velocity of gross assimilation was found with the following order: phenylalanine>valine, glutamic acid>serine, arginine>tryptophan>glycine. The assimilation velocities of amino acids in these laboratory works showed almost the same order as those in field experiments. The assimilation velocity of an amino acid was influenced by coexisting another amino acids or glucose. The assimilation velocity in lower substrate range of amino acids was directly proportional to the number of bacterial cells in the range from 6×102 to 3×104 cells per ml. No linear relation between the assimilation velocity of amino acids and reciprocal of absolute temperature was found, but a marked bending was observed at 15 to 20C. The velocity at the optimum temperature was three to six times of that at 5C.  相似文献   

19.
Water surface elevations(t), vertical surface velocities and vertical surface acceleration of wind-generated waves have been measured in a laboratory wind wave channel by using resistance-type wave gauges combined with an electronic differentiation circuits. Probability distributions of the values of(t), , and have been determined from the wave records.In an initial stage of wave generation,i.e., when wind waves are generated at short fetches and low wind speeds, the observed distributions for(t), and are appreciately good fit to the distributions given by successive sum of a Gram-Charlier series, which has been derived following the formulation ofLonguet-Higgins (1963), by taking the weakly nonlinear effect into account.However, when wind waves develop with increasing wind speeds and fetches, the observed distributions deviate gradually from the Gram-Charlier series. Particularly, the deviations are remarkable for the distribution of .When the wind speed increases, the observed distributions of(t), and show the following characteristics: (i) the skewnesses of the distributions of(t) and decrease slightly, (ii) the skewness of changes, at some wind speed, from positive small values to relatively large negative values, (iii) the kurtosis of the distribution of(t) decreases slightly but that of increases slightly and these characteristics seem to depend not so much on fetches, (iv) the kurtosis of the distribution of increases rapidly.  相似文献   

20.
Siome, which was firstly defined by Uda (1938); is a line of convergence on the sea surface. There are many kinds of siome in the sea. I propose in this paper that siome should be classified into streak and front. Streak is defined as the convergence within the same water mass and front the convergence between two different water masses. Streaks and fronts are classified into more details on the basis of their mechanisms of generation. The proposed classification will be useful for understanding the dynamics of siome and should help to promote interdisciplinary studies around siome regions.  相似文献   

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