Iodine in the surface water of the ocean     

Shizuo Tsunogai  Takashi Henmi 《Journal of Oceanography》1971,27(2):67-72

Iodine in sea water of the Pacific was determined with special interest in the relation between iodide and iodate in the surface water of the ocean. The result was discussed with reference to the mechanism of iodide formation proposed byTsunogai andSase. The concentration of iodide varies widely from the lower value than the detection limit to 0.21g at./l, while the concentration of total iodine is nearly constant and the mean value is 0.41g at./l. The vertical profile of iodide often shows the maximum in the surface layer. In the surface layer, the concentration of iodide is higher in warm water (0,10g at./l on the average) than that in cold water of lower temperature than 20° C (0.03g at/l). The highest concentration of iodide among the warm waters is found in the surface water of the equatorial area (0.13g at./l) where the biological productivity is also high. Iodide is generally more enriched in the water having higher biological activity even in the cold water. These results are considered to be compatible with the mechanism of iodide formation proposed.  相似文献   

A preliminary study of carbon system in the East China Sea   总被引：1，自引：0，他引：1  

Shizuo Tsunogai  Shuichi Watanabe  Junya Nakamura  Tsuneo Ono  Tetsuro Sato 《Journal of Oceanography》1997,53(1):9-17

In the central part of the East China Sea, the activity of CO₂ in the surface water and total carbonate, pH and alkalinity in the water column were determined in winter and autumn of 1993. The activity of CO₂ in the continental shelf water was about 50 ppm lower than that of surface air. This decrease corresponds to the absorption of about 40 gC/m²/yr of atmospheric CO₂ in the coastal zone or 1 GtC/yr in the global continental shelf, if this rate is applicable to entire coastal seas. The normalized total carbonate contents were higher in the water near the coast and near the bottom. This increase toward the bottom may be due to the organic matter deposited on the bottom. This conclusion is supported by the distribution of pH. The normalized alkalinity distribution also showed higher values in the near-coast water, but in the surface water, indicating the supply of bicarbonate from river water. The residence time of the East China Sea water, including the Yellow Sea water, has been calculated to be about 0.8 yr from the excess alkalinity and the alkalinity input. Using this residence time and the excess carbonate, we can estimate that the amount of dissolved carbonate transported from the coastal zone to the oceanic basin is about 70 gC/m²/yr or 2 GtC/yr/area-of-global-continental-shelf. This also means that the rivers transport carbon to the oceans at a rate of 30 gC/m²/yr of the coastal sea or 0.8 GtC/yr/ area-of-global shelf, the carbon consisting of dissolved inorganic carbonate and terrestrial organic carbon decomposed on the continental shelf.  相似文献   

Air-Sea Gas Transfer Velocity in Stormy Winter Estimated from Radon Deficiency     

Hitoshi Kawabata  Hisashi Narita  Koh Harada  Shizuo Tsunogai  Masashi Kusakabe 《Journal of Oceanography》2003,59(5):651-661

Thirteen vertical profiles of ²²⁶Ra and ²²²Rn in the near-surface water were obtained in the western North Pacific in winter, and the gas transfer velocities across the air-sea interface were estimated. The transfer velocities found by applying a steady state model varied widely from 2.1 to 30.2 m day⁻¹ with a mean of 9.4 m day⁻¹. The mean value is almost 5 times higher than that in summer in other oceans, and the maximum value is a record high for world oceans. This is partly due to the inadequacy of the steady state model, which overestimates when stronger winds blow in more recent days than the ²²²Rn half-life of about 4 days. In fact, a strong low pressure zone passed through the station about 2 days earlier, which was one of the low pressure zones that with a period of develop once a week or so in the northwestern North Pacific in winter. Instead of steady-state removal, if half of the radon removal occurred sporadically every 7 days, and the last removal took place two days before the observation, the transfer velocity would be 26 m day⁻¹. Our mean transfer velocity, which is less than 20% different from the steady state value including both overestimated and underestimated values, 9.4 ± 4.8 m day⁻¹, seems to represent the mean state of this region in winter. This suggests that the gas exchange fluxes under extremely rough conditions in the open ocean are larger than those estimated by using a transfer velocity equation with a linear or quadratic relationship with wind speed. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Radiocarbon anomaly found in aquicultural scallops suspended in coastal sea     

Shizuo Tsuncgai  Manabu Tsuzuki  Shuichi Watanate  Naohiro Yoshida 《Journal of Oceanography》1993,49(1):31-37

The radiocarbon content of scallops aquiculturally suspended and grown in coastal sea, Funka Bay, were determined. While the ¹⁴C values of carbonate shells coincided with that of ambient seawater, those of soft tissues were smaller than the seawater value and varied rather widely. To clarify the cause of this variation, we further divided the soft tissues of composite scallops into each organ and determined their radiocarbon content. The results show that only the ¹⁴C of adductor (Kaibashira in Japanese) of scallops was significantly smaller than the others, those of gill and mantle coincided to that of seawater. This strange finding cannot be explained by the present knowledge on the dietary sources of scallops and the present theory of isotopic fractionation, unless any unknown physiological or oceanographical process determines the radiocarbon content of the organisms.  相似文献   

Physical oceanography   总被引：2，自引：0，他引：2  

K. Yoshida  K. Takano  T. Teramoto  Y. Toba  Y. Nagata  K. Kajiura  T. Nan'nichi  N. Iwata  T. Takahashi  M. Chaen  T. Tabata 《Journal of Oceanography》1971,27(6):248-264

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超浅海风暴潮的数值模拟(一)——零阶模型对渤海风潮的初步应用   总被引：3，自引：3，他引：3  

孙文心  冯士筰  秦曾灏 《海洋学报》1979,1(2):193-211

由我国北方的寒潮或冷空气所引起的渤海风潮,按文献的分析,该属于“超浅海风暴潮”类型.以渤海风潮为例,按超浅海风暴潮理论进行数值计算,不仅对该理论是一有力的检验,且对探讨渤海风潮的机制和预报也是一个有益的参考. 将冷锋所造成的大风风场重现在计算网格上,在现场海面风资料极度贫乏的情况下,显然是一较难的课题.本文仅就发生渤海风潮时,渤海上空风场的几个主要力学特征,设计了几个理论模式风应力场,对渤海风潮进行了数值计算,以期获得全过程概貌及主要特征.计算结果达到了这一预期目的.  相似文献   

Experimental study of the breaking limit of multi-directional random waves passing over an impermeable submerged breakwater     

D. -S. Hur  N. Kawashima  K. Iwata 《Ocean Engineering》2003,30(15):1923-1940

This study investigates experimentally the breaking wave height of multi-directional random waves passing over an impermeable submerged breakwater. Experiments have been conducted in a three-dimensional wave basin equipped with a multi-directional random wave generator. A special type of wave gauge has been newly devised to record the water surface elevations in the breaker zone as accurately as possible. The records are analyzed to estimate the location and limit of wave breaking. Comparisons have also been made with the results of regular waves. The influence of the incident wave conditions on the breaking wave height normalized by the breakwater dimensions has been investigated. Empirical formulae have been presented to estimate the breaking limit of multi-directional random waves based on the experimental records. The formulae have been tested and found to work well not only for multi-directional random waves, but for regular waves as well.  相似文献   

Identification of constitutive androstane receptor cDNA in northern fur seal (Callorhinus ursinus)     

Hiroki Sakai  Hisato Iwata  Eun-Young Kim  Shinsuke Tanabe  Norihisa Baba 《Marine environmental research》2004,58(2-5):107

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Structural evolution of the Bayanhongor region, west-central Mongolia     

Soichi Osozawa  Gonchig Tsolmon  Uondon Majigsuren  Jargalan Sereenen  Shigeaki Niitsuma  Naoyoshi Iwata  Terry Pavlis  Bor-ming Jahn 《Journal of Asian Earth Sciences》2008,33(5-6):337-352

Most of previous models suggest that the Central Asia Orogenic Belt grew southward in the Phanerozoic. However, in the Bayanhongor region in west-central Mongolia, volcanic arc, accretionary prism, ophiolite, and passive margin complexes accreted northeastward away from the Baydrag micro-continent, and hence the region constitutes the southwestern part of a crustal-scale syntaxis close to the west. The syntaxis should be original, because presumably reorientation due to strike-slip faulting can be ignored. It is reconfirmed that the Baydrag eventually collided with another micro-continent (the Hangai) to the northeast. A thick sedimentary basin developed along the southern passive margin of the Hangai micro-continent. This region is also characterized by an exhumed metamorphosed accretionary complex and a passive margin complex, which are both bounded by detachment faults as well as basal reverse faults which formed simultaneously as extrusion wedges. This part of the Central Asia Orogenic Belt lacks exhumed crystalline rocks as observed in the Himalayas and other major collisional orogenic belts. In addition, we identified two phases of deformation, which occurred at each phase of zonal accretion as D1 through Cambrian and Devonian, and a synchronous phase of final micro-continental collision of Devonian as D2. The pre-collisional ocean was wide enough to be characterized by a mid-ocean ridge and ocean islands. Two different structural trends of D1 and D2 are observed in accretionary complexes formed to the southwest of the late Cambrian mid-ocean ridge. That is, the relative plate motions on both sides of the mid-ocean ridge were different. Accretionary complexes and passive margin sediments to the northeast of the mid-ocean ridge also experienced two periods of deformation but show the same structural trend. Unmetamorphosed cover sediments on the accretionary prism and on the Hangai micro-continent experienced only the D2 event due to micro-continental collision. These unmetamorphosed sediments form the hanging walls of the detachment faults. Moreover, they were at least partly derived from an active volcanic arc formed at the margin of the Baydrag micro-continent.  相似文献   

Source inversion for estimating the continuous slip distribution on a fault—introduction of Green's functions convolved with a correction function to give moving dislocation effects in subfaults     

Haruko Sekiguchi  Kojiro Irikura  Tomotaka Iwata 《Geophysical Journal International》2002,150(2):377-391

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