Vertical residual flow in Kasado Bay     

Tetsuo Yanagi 《Journal of Oceanography》1979,35(3-4):168-172

Some observations were carried out to understand the structure of the vertical residual flow in Kasado Bay. The results of current measurements at three points in the lower layer indicated that a horizontal counterclockwise tidal residual circulation converges in the lower layer. The velocity of upward residual flow was estimated to be about 4.5×10^–3 cm s^–1. The distributions of water temperature, salinity and grain size in the sediment support the existence of this upward motion.  相似文献   

Episodic outflow of suspended sediments from the Kii Channel to the Pacific Ocean in winter     

Tetsuo Yanagi  Takahide Hagita  Toshiro Saino 《Journal of Oceanography》1994,50(1):99-108

Episodic outflow of suspended sediments from the Kii Channel to the Pacific Ocean in winter was observed by the sediment traps experiment above the shelf slope. When the current speed was weak and its direction was south or southwestward above the shelf slope the sinking sediment flux was nearly zero but the sinking sediment flux increased to 22g m^–2 day^–1 after the current speed was strong, its direction changed to south-west or westward and water temperature fell. Such intermitten sinking sediment flux above the shelf slope is considered to be related to the intermittent intrusion of the turbid and cold shelf water into the sub-surface layer of the transparent and warm slope water. Such episodic events may play a very important role in the material transport from the coastal sea to the open ocean.  相似文献   

Seasonal variation in the transport of suspended matter in the East China Sea   总被引：8，自引：0，他引：8  

Tetsuo Yanagi  Satoru Takahashi  Akira Hoshika  Terumi Tanimoto 《Journal of Oceanography》1996,52(5):539-552

Seasonal variation in the transport of suspended matter across the East China Sea is investigated with the use of results of field observations and diagnostic numerical experiments. Suspended matter is transported from the shelf edge to the inner shelf in summer and from the inner shelf to the shelf edge in autumn and winter due to the vertical circulation mainly induced by the monsoon wind. The maximum transport of suspended matter from the inner shelf to the shelf edge occurs in autumn.  相似文献   

Coastal upwelling and downwelling events in the Seto Inland Sea     

Tetsuo Yanagi 《Journal of Oceanography》1985,41(6):435-440

Prominent coastal upwelling and downwelling events due to Ekman transport were observed during the period from 14 to 18 August 1983 along the Misaki Peninsula in the Seto Inland Sea, Japan. The coastline of the Misaki Peninsula is aligned approximately in an ENE-WSW direction. When an ENE wind continued blowing for about two days, the warm water in the upper layer was pushed offshore and cold water in the lower layer upwelled along the peninsula. The estimated upwelling speed 3 m below the sea surface was 0.032 cm sec^–1. On the other hand, when a WSW wind continued blowing for about two days the warm water in the upper layer sank into the lower layer along the peninsula. The estimated downwelling speed 3 m below the sea surface was 0.080 cm sec^–1. The time lag between the variations of the alongshore wind and offshore current was about 0.5 days.  相似文献   

Convergence,divergence and vertical velocity at a tidal front in Hiuchi-Nada,Japan   总被引：2，自引：0，他引：2  

Tetsuo Yanagi  Koji Ishikawa  Koh-ichi Inoue  Satoshi Susami 《Journal of Oceanography》1995,51(2):225-238

The detailed flow structure around a tical front in Hiuchi-Nada, Japan was observed with the use of ADCP (Acoustic Doppler Current Profiler). The surface convergence region is observed at the transition zone between vertically well mixed area and the stratified area. The surface divergence regions exist next to the surface convergence region. The strong downward current is estimated in the middle layer just below the surface convergence region. The maximum surface convergence and the maximum downward velocity in the middle layer are 1.0×10^–4 s^–1 and 0.12 cm s^–1, respectively.  相似文献   

Seasonal variation of water temperature in the Seto Inland Sea     

Tetsuo Yanagi 《Journal of Oceanography》1984,40(6):445-450

The seasonal variation of water temperature in the Seto Inland Sea, Japan is examined using data analysis and numerical experiments and is shown to be controlled by heat exchange through the sea surface and horizontal heat dispersion from the Pacific Ocean. The average water temperature goes down from the Pacific Ocean to the center of the Seto Inland Sea indicating that 4.0 to 6.0×10¹⁵ cal day^?1 (1.6 to 2.5×10¹⁶ joule day^?1) of heat is transported from the Pacific Ocean to the Seto Inland Sea and is lost through the sea surface. The amplitude of seasonal variation of water temperature is large at the center of the Seto Inland Sea and the maximum water temperature is reached first at Bisan Straits and last at Iyo-Nada.  相似文献   

Tidal energy balance in the Seto Inland Sea     

Tetsuo Yanagi  Hidetaka Takeoka  Hideshi Tsukamoto 《Journal of Oceanography》1982,38(5):293-299

The tidal volume transport in the Seto Inland Sea is calculated. The cross-section where the volume transport of the M₂ tide is zero, is located around the western part of Bisan Strait. The tidal energy dissipation of the M₂ tide by friction is 6.30×10¹⁶ ergs s^–1 in the Seto Inland Sea. The quality factorQ for the M₂ tide is 20.2. The total energy dissipation of the M₂, S₂, K₁ and O₁ tides is 7.99×10¹⁶ ergs s^–1.  相似文献   

Water exchange between Tokyo Bay and the Pacific Ocean during winter     

Tetsuo Yanagi  Hirofumi Hinata 《Ocean Dynamics》2004,54(3-4):452-459

Variability in water-exchange time between Tokyo Bay and the Pacific Ocean during winter is investigated based on the results of intensive field observation from November 2000 to March 2001. Water-exchange time between Tokyo Bay and the Pacific Ocean during winter mainly depends on the strength of northerly monsoon, being about 16 days under the weak monsoon and about 12 days under the strong monsoon. Moreover, it becomes longer by about 1 day in spring tide and shorter in neap tide due to the coupling effect of estuarine circulation and vertical mixing. Water-exchange time also varies depending on the open-ocean condition. When the warm water mass approaches from the Pacific Ocean to the mouth of Tokyo Bay through the eastern channel of Sagami Bay, which connects Tokyo Bay and the Pacific Ocean, water-exchange time becomes longer by about 2 days because the warm water mass is blocked in the surface layer at the bay mouth. On the other hand, when the warm water mass approaches to the mouth of Tokyo Bay through the western channel of Sagami Bay, water-exchange time becomes shorter by about 1 day because the warm water mass intrudes into the middle or lower layers of Tokyo Bay. Such different behavior of warm water mass at the mouth of Tokyo Bay is due to the difference in density of approaching warm water masses, that is, the density of the warm water mass through the eastern channel is smaller than that of the warm water mass through the western channel of Sagami Bay.Responsible Editors: Yens Kappenberg  相似文献   

Apatite Composition of Representative Magnetite‐series and Ilmenite‐series Granitoids in Japan          下载免费PDF全文

Shunso Ishihara  Takeru Moriyama 《Resource Geology》2016,66(1):55-62

Apatites of representative magnetite‐series and ilmenite‐series granitoids were studied in the Japanese Islands. Concentrations of the volatile components F, Cl and SO₃ are differently distributed in apatites of these granitoid series. Apatites are always fluoroapatite. They have weakly higher F content in the ilmenite series than in the magnetite series. In contrast, Cl and SO₃, are significantly concentrated in apatites of the magnetite series compared to the ilmenite series. These characteristics reflect the original concentrations of these components in the host granitic magmas. A high fO₂ seems most important for the S‐concentration as sulfate in apatite of the magnetite series. REE and Y are only erratically high in the studied apatites.  相似文献   

Seasonal variation of horizontal material transport through the eastern channel of the Tsushima Straits   总被引：2，自引：2，他引：0  

Akihiko Morimoto  Tetsutaro Takikawa  Goh Onitsuka  Atsushi Watanabe  Masatoshi Moku  Tetsuo Yanagi 《Journal of Oceanography》2009,65(1):61-71

We conducted hydrographic observations ten times in the Tsushima Strait to reveal seasonal variations of horizontal material transports such as of heat, freshwater, chlorophyll a, and dissolved inorganic nitrogen (DIN) and phosphorus (DIP) through the eastern channel of the Tsushima Strait (ECTS). The volume, freshwater, and heat transport results are of nearly the same order as results reported in previous studies. The annual mean DIN and DIP transports of 3.59 kmol/s and 0.29 kmol/s are large relative to those of the Changjiang and the Taiwan Strait and are horizontally transported through the ECTS. Nutrient transports are high in July–August and October and low in April and November. Increased nutrient transports in July–August and October are due to the appearance of a cold saline water mass in the bottom layer of the ECTS. Changes in DIN transports in summer and autumn, which account for two-thirds of the total annual DIN transport, would have a large effect on the nitrogen budget and biological productivity in the Tsushima Warm Current region.  相似文献