Secondary metabolites of cyanobacteriaNostoc sp.     

Kobayashi  Akio  Kajiyama  Shin-ichiro 《中国海洋湖沼学报》1998,16(1):109-117

Cyanobacteria attracted much attention recently because of their secondary metabolites with potent biological activities and unusual structures. This paper reviews some recent studies on the isolation, structural, elucidation and biological activities of the bioactive compounds from cyanobacteriaNostoc species.

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Current observation system using ship drift and its applications in Kumano-nada and Enshu-nada Seas     

Takashige Sugimoto  Masato Kobayashi 《Journal of Oceanography》1987,43(6):363-376

A continuous observation system of ship drift of ferry boats was developed using Loran C, ship direction, ship speed and wind velocity measurement. A formula to estimate the wind-driven lateral drift of the boat is proposed, and a measuring system of the surface current is described, including a discussions on its usefullness to monitor day-to-day variations of the circulation patterns in the coastal boundary regions of the Kuroshio.This system was applied to observe variations of the circulation in the Kumano-nada, and Enshu-nada Seas south of Japan. Some preliminary results were obtained by using this system as well as other methods. This work focuses on the behavior of warm eddies in the Kumano-nada Sea. The surface current patterns that include these phenomena obtained by the use of the ship drift show good correspondence with currents and thermal structures observed with GEK, CTD, moored current meters and satellite thermal images.  相似文献   

Moored instrument observations in the Kuroshio south of Kyushu   总被引：1，自引：0，他引：1  

Masaki Takematsu  Kazuo Kawatate  Wataru Koterayama  Toshiro Suhara  Hisashi Mitsuyasu 《Journal of Oceanography》1986,42(3):201-211

In each of the (fiscal) years 1979–1982, multilayer current measurements by means of moored instruments were carried out in the Kuroshio off Tanegashima Island, south of Kyushu, with particular interest in the baroclinic layer (0–1,000 m) of the intense current. Most of the moored instruments were in position for more than 30 days, the maximum duration being 145 days. This paper describes some noticeable features of the mean and fluctuation fields in the surface Kuroshio as inferred from the the new data sets.Vertical profiles of horizontal velocities show that the eastward current of the Kuroshio in the region is confined to the upper 600 m on average and below this level the mean current is directed to the southwest along the local isobaths. This is believed to be the first observation of the level of no motion in this region. It is argued that the indicated level of no motion would lead to much smaller values for the Kuroshio transport than previous values referred to the 1,000 m level — for example, earlier estimates by Nitani (1972).The fluctuation field in the upper intense current appears to be dominated by an organized motion with a time scale of about 30 days. This can be seen clearly in the time variations of water temperature and local volume transport, but less clearly in the velocity records. The horizontal transfer components of momentum and heat are calculated and it is suggested that the transverse momentum transfer, UV tends to be negative (offshore) in the region of anticyclonic shear of the upper Kuroshio; no evidence for a negative eddy viscosity effect is found.  相似文献   

Downstream transition of the Tsushima Current west of Kyushu in summer   总被引：1，自引：0，他引：1  

Osamu Katoh  Kazuyuki Teshima  Katsuhiko Kubota  Kazuo Tsukiyama 《Journal of Oceanography》1996,52(1):93-108

In order to clarify detailed current structures west of Kyushu, ADCP measurements were carried out in July and September 1990 by the quadrireciprocal method (Katoh, 1988) for removing diurnal and semidiurnal tidal flows from observed flows. On the basis of these results, together with data of routine oceanographic observations, we study the downstream transition of the Tsushima Current west of Kyushu in summer. In the southwest of the Goto Islands, a northward current identified as the Tsushima Current was clearly found. In the south of Cheju, a westward current bifurcated from the Tsushima Current. In the northwest of the Goto Islands, the Tsushima Current narrowed and its velocity became strengthened. Salinity of the Tsushima Current water was much diluted by a current from the Cheju Strait. Near the west coast of the Goto Islands, a countercurrent bifurcating from the Tsushima Current often occurred. The volume transport of the Tsushima Current was 2.3 Sv (1 Sv=10⁶ m³s^–1) on the northern side of latitude 31°N. The substantial bifurcation of the Tsushima Current toward the Eastern and Western Channels of the Tsushima Strait occurred in the vicinity of Tsushima. The volume transport through the Western Channel was two to three times larger than that through the Eastern Channel. The baroclinic component in volume transport of the Tsushima Current west of Kyushu was much smaller than that in the Japan Sea.  相似文献   

A dynamic two-dimensional calculation of underwater lines     

Kazuo Kawatate 《Progress in Oceanography》1986,17(3-4)

On the basis of a lumped mass method in two-dimension, we derive a dynamic calculation method for a system including both extensible and inextensible underwater lines. The Newmark beta method is used in numerical integration with respect to time. The Newton Raphson method is applied so that the numbers of iterations are reduced. A transient response of a line during deployment is calculated.  相似文献   

History and present status of the fishery of Sergestes lucens (Penaeidea, Decapoda, Crustacea) in Suruga Bay, Japan     

Omori  Makoto; Konagaya  Teruo; Noya  Kazuo 《ICES Journal of Marine Science》1973,35(1):61-77

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Pre-Japan-ARGO: Experimental Observation of Upper and Middle Layers South of the Kuroshio Extension Region Using Profiling Floats     

Naoto Iwasaka  Toshio Suga  Kensuke Takeuchi  Keisuke Mizuno  Yasushi Takatsuki  Kentaro Ando  Taiyo Kobayashi  Eitarou Oka  Yasuko Ichikawa  Motoki Miyazaki  Hiroshi Matsuura  Kenji Izawa  Chan-Su Yang  Nobuyuki Shikama  Momoko Aoshima 《Journal of Oceanography》2003,59(1):119-127

We deployed two profiling floats in the region south of the Kuroshio Extension in March 2000. Temperature and salinity profiles from a depth of 1500 × 10⁴ Pa to the surface are reported every two and four weeks, respectively. The floats performed very well for first four months after deployment. Later they failed in surfacing for a few months when the sea surface temperature in the region was high. The salinity sensors seemed to suffer from some damage during their failure-in-surfacing period. Despite this trouble, the results clearly demonstrate that the profiling float is a very useful and cost-effective tool for physical oceanographic observation in the open sea. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Sedimentation flux from mariculture of oyster (Crassostrea Gigas) in Ofunato estuary, Japan   总被引：1，自引：0，他引：1  

Hayakawa  Y.; Kobayashi  M.; Izawa  M. 《ICES Journal of Marine Science》2001,58(2):435-444

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Air-sea exchange of mercury in Tokyo Bay     

Masahiro Narukawa  Masahiro Sakata  Kohji Marumoto  Kazuo Asakura 《Journal of Oceanography》2006,62(3):249-257

In Tokyo Bay the concentrations of dissolved gaseous mercury (DGM) in the surface seawater and total gaseous mercury (TGM) over the sea were measured during December 2003, October 2004 and January 2005. Based on these data, the evasional fluxes of mercury from the sea surface were estimated using a gas exchange model. In addition, an automatic wet and dry deposition sampler was used to measure the wet and dry depositional fluxes of mercury from December 2003 to November 2004 at three locations in and near Tokyo Bay. The results indicate that the average DGM and TGM levels of seven locations are 52 ± 26 ng m⁻³ and 1.9 ± 0.6 ng m⁻³, respectively, which shows that the surface seawater in Tokyo Bay is supersaturated with gaseous mercury, leading to an average mercury evasional flux of 140 ± 120 ng m⁻²d⁻¹. On the other hand, the annual average wet and dry depositional fluxes of mercury at three locations were 19 ± 3 μg m⁻²yr⁻¹ and 20 ± 9 μg m⁻²yr⁻¹, respectively. These depositional fluxes correspond to the daily average total depositional flux of 110 ± 20 ng m⁻²d⁻¹. Thus, it is suggested that in Tokyo Bay, the evasional fluxes of mercury are comparable to the depositional fluxes.  相似文献   

Regional　characteristics　of　stress　field　in　the　southern　part　of　the　north－south　seismic　belt　in　China　and　its　relation　with　plate　movement     

徐纪人  尾池和夫 《地震学报(英文版)》1995,8(1):39-49

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