A numerical study on the formation and variation of a clockwise-circulation during winter in the Yellow Sea   总被引：1，自引：0，他引：1  

Satoru Takahashi  Yutaka Isoda  Tetsuo Yanagi 《Journal of Oceanography》1995,51(1):83-98

In the Yellow Sea, the north-westerly wind dominates in winter and the existence of horizontal clockwise circulation has been suggested (Yanagi and Takahashi, 1993). The formation and variation mechanisms of this clockwise circulation is investigated using the wind forced numerical model which has a simplified basin configuration of the Yellow Sea. The model results show that two vortices (an anticlockwise vortex off Chinese coast and a clockwise vortex off Korean coast) are generated by the uniform north-westerly wind. Both vortices propagate along the shelf slope as the first mode shelf waves. An anti-clockwise vortex can not grow because it does not balance to the wind forcing. On the other hand, a clockwise vortex can grow and it reaches to the equilibrium condition at the northern part of the Yellow Sea, because this circulation can balance to the wind forcing. The time scale to become into the equilibrium condition is about 2 days. From this fact, it is ascertained that a clockwise circulation in the basin is generated periodically according to the variable wind forcing with 4 days period. The steady part of the current field exists with the fluctuating one which is induced by the periodical north-westerly wind.  相似文献   

II-4 Fundamental studies on oscillating water column wave power generator with wells turbine     

Masami Suzuki  Chuichi Arakawa  Tetsuo Tagori 《Ocean Engineering》1985,12(6):565

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Seasonal Variations in Inorganic Nutrient Budgets of the Bangpakong Estuary, Thailand     

Anukul Buranapratheprat  Tetsuo Yanagi  Thanomsak Boonphakdee  Pichan Sawangwong 《Journal of Oceanography》2002,58(4):557-564

Seasonal variations in freshwater, salt, dissolved inorganic phosphorus (DIP) and dissolved inorganic nitrogen (DIN) in the Bangpakong estuary, Thailand were investigated by employing the database obtained in the National Research Council of Thailand (NRCT)-Japan Society for the Promotion of Science (JSPS) cooperative project from 1994 to 1997. The results showed that variation in interaction between coastal sea and river discharge played an important role in controlling the characteristics of the water in the estuary. Residence time of fresh water was short in wet season and dry season, but it was long in the transition period from season to season. DIP and DIN load depended on river discharge, while high peak concentrations were related to loading and the long residence time in the transition period between dry and wet seasons. A strong eutrophic condition could possibly occur when the concentration of DIP and DIN were high during the onset of the wet season from April to July. The annual average of inorganic nutrient budgets indicated that the Bangpakong estuary is the internal source of 38.2 tons/month DIP and the internal sink of 4.9 tons/month DIN. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

A carbon budget in Tokyo Bay     

Tetsuo Yanagi  Toshiro Saino  Takashi Ishimaru  Shin-ichi Uye 《Journal of Oceanography》1993,49(3):249-256

Organic carbon flux from eutrophicated Tokyo Bay to the Pacific Ocean is estimated as 260 ton C day^–1 based on the horizontal gradient of COD and the dispersion coefficient at the bay mouth. Also, carbon flux from the air or from the open ocean to Tokyo Bay is estimated as 156 ton C day^–1. If we suppose that five percent of the coastal seas in the world might be eutrophicated as Tokyo Bay and the organic carbon flux from the shelf to the open ocean in other coastal seas might be one third of that in Tokyo Bay, 1.12 G tons year^–1 would be transported from the eutrophicated coastal seas to the open ocean and such carbon flux may account for the missing sink in the global carbon budget.  相似文献   

Estimation of Sediment Properties during Benthic Impact Experiments     

Tetsuo Yamazaki  Rahul Sharma 《Marine Georesources & Geotechnology》2001,19(4):269-289

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.  相似文献   

Eddy Activities around the Nansei Shoto (Okinawa Islands) Revealed by TRMM     

Tetsuo Yanagi  Tsutomu Tokeshi  Shin-ichiro Kakuma 《Journal of Oceanography》2002,58(4):617-624

Sea surface temperature (SST) variation around the Nansei Shoto (Okinawa Islands), Japan from March 1998 to February 1999 is investigated using the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) images. Root mean squared (RMS) error of SST by TMI from the in situ observed SST is 0.9°C. The results of statistical analysis of SST by TMI show that a 14–16 days period variation dominates around the main Okinawa Island, while a 9–11 days period variation dominates along the shelf edge of the East China Sea. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Seasonal variation of residual current in Tokyo Bay,Japan —diagnostic numerical experiments—     

Xinyu Guo  Tetsuo Yanagi 《Journal of Oceanography》1996,52(5):597-616

The residual currents in Tokyo Bay during four seasons are calculated diagnostically from the observed water temperature, salinity and wind data collected by Unokiet al. (1980). The calculated residual currents, verified by the observed ones, show an obvious seasonal variable character. During spring, a clear anticlockwise circulation develops in the head region of the bay and a strong southwestward current flows in the upper layer along the eastern coast from the central part to the mouth of the bay. During summer, the anticlockwise circulation in the head region is maintained but the southwestward current along the eastern coast becomes weak. During autumn, the preceding anticlockwise circulation disappears but a clockwise circulation develops in the central part of the bay. During winter, the calculated residual current is similar to that during autumn. As a conclusion, the seasonal variation of residual current in Tokyo Bay can be attributed to the variation of the strength of two eddies. The first one is the anticlockwise circulation in the head region of the bay, which develops in spring and summer and disappears in autumn and winter. The second one is the clockwise circulation in the central part of the bay, which develops in autumn and winter, decreases in spring and nearly disappears in summer.  相似文献   

Variability of the constant flow in Ôsaka Bay     

Tetsuo Yanagi 《Journal of Oceanography》1980,36(5):246-252

Some current measurements were carried out in Ôsaka Bay to understand the characteristics and causes of fluctuations of the constant flow in the bay. It is shown that the major part of fluctuation of the constant flow in Ôsaka Bay is the wind-driven current. The direction of the wind-driven current in the near surface water deflects clockwise through 10 to 30 degrees from the wind direction while in the lower layer the current deflects counter-clockwise to that in the near surface water in the eastern half of Ôsaka bay. The speed of the wind-driven current in the near surface water is 0.5 to 1.5% of the wind speed while that in the lower layer is smaller than that in the near surface water in this area.  相似文献   

Water, Salt, Phosphorus and Nitrogen Budgets of the Japan Sea   总被引：1，自引：0，他引：1  

Tetsuo Yanagi 《Journal of Oceanography》2002,58(6):797-804

Water, salt, phosphorus and nitrogen budgets of the Japan Sea have been calculated by box model analysis using historical data. Average residence time of the Tsushima Warm Current Water in the upper 200 m is 2.1 years and that of the Japan Sea Proper Water is 90 years. The salt flux from the Tsushima Strait balances those through the Tsugaru and Soya Straits. Average residence times of phosphorus and nitrogen from the Tsushima Strait are 2.2 years and 1.6 years, respectively, in the upper 200 m of the Japan Sea. Total nitrogen/total phosphorus ratios of riverine load, the Tsushima Warm Current water and the water in the Japan Sea are 16.4, 16.6 and 11.3, respectively. This suggests that denitrification is dominant in the Japan Sea. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Bunnoite,a new hydrous manganese aluminosilicate from Kamo Mountain,Kochi prefecture,Japan     

Daisuke Nishio-Hamane  Koichi Momma  Ritsuro Miyawaki  Tetsuo Minakawa 《Mineralogy and Petrology》2016,110(6):917-926

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