掲載種別：研究論文（学術雑誌）  

© 2020 Elsevier Ltd A model of the beach process of marine plastics was proposed based on the assumption of the beaching and backwashing flux balance, and its applicability was examined by means of time-invariant linear system analysis and particle tracking experiments with respect to the ratio between the residence time of plastics on a beach (τr) and the period of nearshore current variability (T0). Based on the theory, the balance was expected to hold when τr/T0 was much smaller than 1; however, good agreement was obtained between the theory and the particle tracking method for much larger values of τr/T0. The parameters, which are diagnostically given in the model, will be prognostically decided by the coastal dynamics in the future to develop robust beach process models. Nevertheless, we believe that a diagnostic approach would be another pillar in the strategy for estimating the amounts and distributions of marine plastics in the coming years.

DOI： 10.1016/j.marpolbul.2020.110910

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）  

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記述言語：日本語   出版者・発行元：公益社団法人 土木学会  

<p> 南海・東南海地震が発生した場合の，直後の数日間の漂流物予測にHFレーダーで観測される津波流速を活用することを目的として，流速データの適切な同化方法の基礎的検討を行った．流動モデルには準3次元流動モデルのROMS（Regional Ocean Modeling System）を使用した．観測流速に含まれる風，潮汐，河川流入に起因する流れを分離し，津波成分のみを同化するために，離散ウェーブレット変換を用いて疑似観測データから高周波成分を抽出し，ナッジングによって同化計算を行った．高周波成分をそのまま同化する場合，成分の強度に応じて同化強度を変化させた場合，ソースとして追加する場合について比較した結果，高周波成分をソースとして追加した場合で，津波第一波の到達，津波収束後の良好な同化計算結果が得られた．</p>

DOI： 10.2208/kaigan.75.I_1315

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記述言語：日本語   出版者・発行元：公益社団法人 土木学会  

<p> 短波海洋レーダによる津波検知性能の季節変化について，和歌山県美浜局の2014年の受信波と南海トラフ地震津波ケース3の数値シミュレーション結果を使った仮想津波観測実験に基づいて調べた．その結果，陸棚上では低波浪（<i>H_s</i> ≤ 1m，及び<i>H_s</i> ≤ 2m）の出現割合に依らずいずれの月も高確率で検知可能であること，陸棚縁〜陸棚斜面上での検知確率と有義波高1m以下の割合，及び陸棚縁と有義波高2m以下の割合には，高い正の相関が認められ，遠距離での検知には低波浪の状態が好ましいことが確認できた．一方，陸棚斜面上での検知確率と2m以下の有義波高との関係には高い相関が認められなかった．その要因として，電離層電子密度の季節変動によって外来ノイズの伝搬経路が変化することが考えられた．</p>

DOI： 10.2208/kaigan.75.I_1309

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier Ltd  

Microplastics have adverse effects on marine life. This study examined the abundance and size of microplastics as well as their polymer types in the surface water and the bottom and beach sediments of Hiroshima Bay. The fragmentation process and sinking factors of foamed polystyrene (FPS) microplastics were also examined. Serious FPS pollution spread out not only in the beach sediments but also in the bottom sediments. The average size of FPS particles in the bottom sediments was significantly smaller than that of beached FPS particles. Field emission scanning electron microscopy images suggest that large amounts of microsized or nanosized FPS fragments are likely to be generated from the margins of beached FPS microplastics. X-ray computed tomography images show that FPS microplastics from the bottom sediments had tunnel-like structures inside the particle. Based on these images, FPS microplastics in the bottom sediments were susceptible to biofouling and soil deposition.

DOI： 10.1016/j.marpolbul.2018.05.036

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

© 2018 by the authors. The tsunami generated by the 2011 Tohoku-Oki earthquake was the first time that the velocity fields of a tsunami were measured by using high-frequency oceanographic radar (HF radar) and since then, the development of HF radar systems for tsunami detection has progressed. Here, a real-time tsunami detection method was developed, based on virtual tsunami observation experiments proposed by Fuji et al. In the experiments, we used actual signals received in February 2014 by the Nagano Japan Radio Co., Ltd. radar system installed on the Mihama coast and simulated tsunami velocities induced by the Nankai Trough earthquake. The tsunami was detected based on the temporal change in the cross-correlation of radial velocities between two observation points. Performance of the method was statistically evaluated referring to Fuji and Hinata. Statistical analysis of the detection probability was performed using 590 scenarios. The maximum detection probability was 15% at 4 min after tsunami occurrence and increased to 80% at 7 min, which corresponds to 9 min before tsunami arrival at the coast. The 80% detection probability line located 3 km behind the tsunami wavefront proceeded to the coast as the tsunami propagated to the coast. To obtain a comprehensive understanding of the tsunami detection probability of the radar system, virtual tsunami observation experiments are required for other seasons in 2014, when the sea surface state was different from that in February, and for other earthquakes.

DOI： 10.3390/rs10071126

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Blackwell Publishing Ltd  

Tsunami waves and the subsequent natural oscillations generated by the 2011 Tohoku earthquake were observed by two high-frequency (HF) radars and four tidal gauge records in Ise Bay. The radial velocity components of both records increased abruptly at approximately 17:00 (JST) and continued for more than 24 h. This indicated that natural oscillations followed the tsunami in Ise Bay. The spectral analyses showed that the tsunami wave arrivals had periods of 16–19, 30–40, 60–90, and 120–140 min. The three longest periods were remarkably amplified. Time-frequency analysis also showed the energy increase and duration of these periods. We used an Empirical Orthogonal Function (EOF) to analyze the total velocity of the currents to find the underlying oscillation patterns in the three longest periods. To verify the physical properties of the EOF analysis results, we calculated the oscillation modes in Ise Bay using a numerical model proposed by Loomis. The results of EOF analysis showed that the oscillation modes of 120–140 and 60–90 min period bands were distributed widely, whereas the oscillation mode of the 30–40 min period band was distributed locally. The EOF spatial patterns of each period showed good agreement with the eigenmodes calculated by the method of Loomis (1975). Thus, the HF radars were capable of observing the tsunami arrival and the subsequent oscillations.

DOI： 10.1029/2017JC013626

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 土木学会  

日本や米国の沿岸に設置された海洋レーダにより，2011年東北地方太平洋沖地震津波の観測に世界で初めて成功し，海洋レーダによる津波検知の可能性が実証された．その後，津波を観測対象とした研究が報告されているが，津波伝搬の検知が中心であり，その挙動をより正確に観測する可能性が期待されている．そこで，本研究では，1局の海洋レーダで津波波峰を推定する手法を検討し，南海トラフ巨大地震津波を対象としてその精度を検証した．南海トラフでの<i>M</i>w9.1，8.6の津波波源を初期条件として津波伝播計算を実施し，海洋レーダで観測される視線方向流速分布から津波波峰推定を実施した．その結果，波峰の位置は良好に推定でき，波峰の水位は-20～10%の誤差範囲で推定できることを明らかにした．

DOI： 10.2208/kaigan.74.I_511

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記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

The combination of a high-frequency ocean surface radar and a tsunami detection method should be assessed as the onshore-offshore distribution of tsunami detection probability, because the probability will vary in accordance with the signal-to-noise ratio (SNR) and the tsunami magnitude in addition to the radar system specifications. Here, we statistically examine the tsunami detection distance based on virtual tsunami observation experiments by using signals received by a high-frequency radar in February 2014 installed on the southern coast of Japan and numerically simulated velocities induced by a Nankai Trough earthquake. In the experiments, the Doppler frequencies associated with the simulated velocities were superimposed on the receiving signals of the radar, and the radial velocities were calculated from the synthesized signals by the fast Fourier transform. Tsunami arrival was then detected based on the temporal change in the cross-correlation of the velocities, before and after tsunami arrival, between two points 3 km apart along a radar beam. We found that the possibility of tsunami detection primarily depends on the kinetic energy ratio between tsunami current and background current velocities. The monthly average detection probability is over 90% when the energy ratio exceeds 5 (offshore distance: 9 km &lt;= L &lt;= 36 km) and reduces to 50% when the energy ratio is approximately 1 (L = 42 km) over the shelf slope. The ratio varied with the background current physics and SNR, which was mainly affected by ocean surface wave heights and ionospheric electron density.

DOI： 10.1007/s10872-017-0428-y

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 土木学会  

海洋レーダによるリアルタイム津波検知手法の性能検証を，藤ら¹⁾によって提案された仮想津波観測実験に基づいて行った．具体的には，レーダビーム上の3 km離れた観測点間の視線方向流速の相互相関係数を算出し，相互相関係数が平常時における相互相関係数の上位1%，5%，10%，15%に相当する値を超えるかどうかを1分毎に判定した．そして，沖側の隣り合う2つの組合せについても同様に津波検知判定を行い，3つの組合せ全てで相互相関係数が閾値を超えた場合に，最も岸側の観測地点で津波を検知したと判断した．内閣府断層パラメータケース3地震津波の発生時刻を2014年2月1日6:00と仮定し検証を行った結果，津波発生後6分に31.5 km沖合で津波を検知した．また，閾値を低く設定すると津波検知時刻は早くなることが分かった．

DOI： 10.2208/kaigan.73.I_1615

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 土木学会  

海洋レーダの観測データから2015年イヤペル地震津波の検知を試みた．流速の時空間分布からは津波を示す大きな流速や流向の変化は見られなかった．津波の伝播計算とチリ沖のDARTの実測値から，日本沿岸ではレーダの観測可能流速を下回っていたことを明らかにした．観測が可能になる津波の規模を明らかにするため，1960年チリ地震津波を対象に数値実験を行なった結果，海洋レーダで観測できる可能性を示した．さらに仮想津波実験を実施することで，より現実の環境に近い状態で観測性能の検討を行った結果，観測流と背景ノイズを考慮しても同津波を観測可能であることを示した．その際，相関算出距離を3km，算出時間を3時間とした時，観測距離は25.5kmであることを明らかにした．

DOI： 10.2208/kaigan.73.I_433

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Residence times of microplastics were estimated based on the dependence of meso- and macrolitter residence times on their upward terminal velocities (UTVs) in the ocean obtained by one- and two-year mark-recapture experiments conducted on Wadahama Beach, Nii-jima Island, Japan. A significant linear relationship between the residence time and UTV was found in the velocity range of about 0.3-0.9 ms(-1), while there was no significant difference between the residence times obtained in the velocity range of about 0.9-1.4 ms(-1). This dependence on the UTV would reflect the uprush-backwash response of the target items to swash waves on the beach. By extrapolating the linear relationship down to the velocity range of microplastics, the residence times of microplastics and the 1D onshore-offshore diffusion coefficients were inferred, and are one to two orders of magnitude greater than the coefficients of the macroplastics.

DOI： 10.1016/j.marpolbul.2017.05.012

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記述言語：日本語   出版者・発行元：土木学会  

DOI： 10.2208/jscejhe.73.I_1225

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/kaigan.72.I_463

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 土木学会  

2011年3月に発生した東北地方太平洋沖地震によって発生した津波が，伊勢湾に設置された海洋レーダで観測された．到来した津波により，120～140分，60～90分および30～40分の周期帯の副振動が湾内に発生していた．海洋レーダおよびLoomisの方法によってこれらの詳細な振動モードを解析した結果，120～140分および60～90分の周期帯の振動モードは湾全体に及ぶ振動であったが，30～40分の周期帯の振動モードは非常に複雑であり，湾内で局所的に振動を増幅させていたことが明らかとなった．

DOI： 10.2208/kaigan.72.I_1723

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

We propose a belt transect setting strategy for mark-recapture experiments (MREs) to evaluate the time-independent 1D diffusion coefficient (&lt; D-p0 &gt;) of marine litter in the cross-shore direction that determines the backwashing flux of the litter, based on two-year MREs for plastic floats (PFs) on Wadahama Beach, Nii-jima Island, Japan. When the alongshore width of the belt transect (L-t) was of the order of, or longer than, the length scale of wave-induced nearshore current circulation (L-c), the PFs were rarely transported alongshore across the selected transects prior to being backwashed offshore. Thus, the transect residence time became longer and showed a much weaker dependence on the transect position, in contrast to when L-t was even shorter than L-c. We therefore obtained the diffusion coefficients close to the value of (&lt; D-p0 &gt;) when we set L-t to the order of, or longer than, L-c. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.marpolbul.2016.05.016

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

A tsunami generated by "The 2011 off the Pacific coast of Tohoku Earthquake" was observed by two high frequency ocean surface radars (HF radars) and four tide gauges installed on Ise Bay. The tsunami wave arrived initially at 16: 50 was observed by tide gauge which is installed on the mouth of the Bay. This wave propagation was also observed by HF radars installed on the inner part of the Bay. Therefore, these observations were considered to be correlated. The result of spectral analysis, the tsunami wave had energy with period bands of 120-140, 60-90 and 30-40 min. In comparison to the previous study suggest that these 60-90 and 30-40 min periods oscillations were attributed to the tsunami source fault.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

A key factor for determining the residence time of macroplastics on a beach is the process by which the plastics are backwashed offshore (backwash process). Here, we deduced the backwash process of plastic fishing floats on Wadahama Beach based on the analysis of two-year mark-recapture experiments as well as nearshore current structures revealed by sequential images taken by za webcam installed at the edge of a cliff behind the beach. The analysis results revealed the occurrence of a combination of offshore currents and convergence of alongshore currents in the surf zone in storm events around a submerged breakwater off the northern part of the beach, where 48% of the backwashed floats were last found. We conclude that the majority of the floats on the beach were transported alongshore and tended to concentrate in the convergence zone, from where they were backwashed offshore by the nearshore currents generated in the events. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.marpolbul.2015.10.060

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本海洋学会沿岸海洋研究部会  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

We established a method for evaluating beach cleanup effects (BCEs) based on a linear system analysis, and investigated factors determining BCEs. Here we focus on two BCEs: decreasing the total mass of toxic metals that could leach into a beach from marine plastics and preventing the fragmentation of marine plastics on the beach. Both BCEs depend strongly on the average residence time of marine plastics on the beach (tau(r)) and the period of temporal variability of the input flux of marine plastics (1). Cleanups on the beach where tau(r) is longer than Tare more effective than those where tau(r) is shorter than T. In addition, both BCEs are the highest near the time when the remnants of plastics reach the local maximum (peak time). Therefore, it is crucial to understand the following three factors for effective cleanups: the average residence time, the plastic input period and the peak time. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.marpolbul.2014.12.026

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

DOI： 10.2208/jscejhe.71.I_1225

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japan Society of Civil Engineers  

海洋レーダの観測受信波を数値モデルで計算した津波流速を使い変調することによって津波発生時におけるレーダ受信波をシミュレートした．この受信波の周波数解析から視線方向流速を計算し，さらにハイパスフィルターとARモデルにより津波流速の視線方向成分を抽出した．そして，レーダビーム上に位置する観測点間の視線方向流速の相互相関係数が津波第１波の通過に伴って有意に上昇した場合にそれらの観測点で津波を検知したと判断した．内閣府断層パラメータケース3地震が2014年4月5日0:00に発生したと仮定し検討を行った結果，観測点間の距離（相関算出距離）が1.5 km，3.0 km，6.0 km，12.0 kmの場合，検知距離はそれぞれ42.0 km，52.5 km，54.0 km，57.0 kmとなり相関係数の算出距離依存性が認められた．

DOI： 10.2208/kaigan.71.I_337

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IAHR-INT ASSOC HYDRO-ENVIRONMENT ENGINEERING RESEARCH  

Most marine debris are primarily supplied from inland areas; however, few monitoring data exist for floating-litter transport from rivers to the ocean due to the absence of appropriate monitoring methods. In this study, we developed an automatic and continuous monitoring technique for floating-litter transport L in rivers by using an image monitoring and processing technique in which different types of litter (scatter-type and mass-type) are separately analyzed. The results indicated that L evaluated by the present methods was in good agreement with the observed data in the Mogami River, Yamagata, Japan, demonstrating the fundamental performance of the present monitoring method.

DOI： 10.2208/jscejhe.71.I_1225

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Large quantities of plastic litter are expected to wash ashore along the beaches of the East Asian marginal seas in the coming decade. Litter quantities were predicted using three techniques: a particle tracking model (PTM) used in conjunction with two-way PTM experiments designed to reveal litter sources, an inverse method used to compute litter outflows at each source, and a sequential monitoring system designed to monitor existing beach litter using webcams. Modeled year-to-year variation in litter quantities indicated that the amount of litter would continue to increase in the East Asian marginal seas if the level of outflow remains constant in the coming decade. The study confirms that about 3% of all East Asian beaches may potentially experience a 250-fold increase in the amount of plastic beach litter washed ashore in the next 10 years. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.marpolbul.2014.01.057

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER GEOPHYSICAL UNION  

This study investigates the horizontal and residual circulations in Tokyo Bay using field observations, numerical simulations, and theoretical analysis. Numerical simulations show that the observed deepening of isopycnals and associated anticyclonic horizontal circulation in the bay head are mainly driven by negative wind stress curl. The effects of river discharge, surface heat fluxes, and tides are found to be small. Under strong wind events, the wind stress curl over the bay head can be large enough to make the surface Ekman layer strongly nonlinear. Theoretical and numerical analyses show that, under large negative wind stress curl, the nonlinearity tends to induce positive pumping velocity (at the base of the surface mixed layer) that counteracts the Ekman pumping; however, the typical duration of wind events in the bay head is not long enough to induce positive pumping under negative wind stress curl. These results and historical wind data suggest that the average horizontal circulation and residual circulation immediately below the surface mixed layer in Tokyo Bay are, respectively, cyclonic and convergent in summer but anticyclonic and divergent in winter.

DOI： 10.1002/2013JC009396

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Blackwell Publishing Ltd  

This study investigates the horizontal and residual circulations in Tokyo Bay using field observations, numerical simulations, and theoretical analysis. Numerical simulations show that the observed deepening of isopycnals and associated anticyclonic horizontal circulation in the bay head are mainly driven by negative wind stress curl. The effects of river discharge, surface heat fluxes, and tides are found to be small. Under strong wind events, the wind stress curl over the bay head can be large enough to make the surface Ekman layer strongly nonlinear. Theoretical and numerical analyses show that, under large negative wind stress curl, the nonlinearity tends to induce positive pumping velocity (at the base of the surface mixed layer) that counteracts the Ekman pumping
however, the typical duration of wind events in the bay head is not long enough to induce positive pumping under negative wind stress curl. These results and historical wind data suggest that the average horizontal circulation and residual circulation immediately below the surface mixed layer in Tokyo Bay are, respectively, cyclonic and convergent in summer but anticyclonic and divergent in winter. © 2014. American Geophysical Union. All Rights Reserved.

DOI： 10.1002/2013JC009396

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 土木学会  

Two oceanographic Radars targeting tsunamis had been installed in Wakayama Prefecture in Japan. To study observation capabilities of the radars on far field and near field tsunamis, numerical experiments were carried out. After starting the operation of the radars, nine earthquakes occurred in the observation area, however, they were too small to be observed by the radars. Parameter study on near field tsunamis showed the radars can observe earthquake of Mw 7 and very shallow Mw 6. As a far field tsunami, the 2012 Haida Gweii Earthquake Tsunami arrived at Japan, however, the radars could not detect it because of very small velocity. Parameter study on far field tsunamis showed the main energy of tsunamis off Canada propagates northward, and Oshika Peninsula is suitable to observe the tsunamis.

DOI： 10.2208/kaigan.70.I_356

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その他リンク： http://hdl.handle.net/10112/8854

記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

The exponential decay of the amount of new litter on Wadahama Beach, Nii-jima Island, Japan revealed by 20-month mark-recapture experiments demonstrates a linear response of the beach to the input of target items. Here we show the amplitude and phase characteristics of the beach as a time-invariant linear input/output system and discuss the hydrodynamic and geomorphological factors that would determine the characteristics with the aid of a diffusion equation. The characteristics are fully determined by the residence time of the items (tau(r) = 209 days) and can be described as functions of the ratio of tau(r) to the period of input variability. The decay is reproduced well by the analytical solution of the equation with a constant diffusion coefficient (D), whose order was estimated by tau(r) and the backshore width. Generally, D would depend on hydrodynamical statistics and beach geomorphology as well as the dimensions and density of the items. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.marpolbul.2013.09.049

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD  

We numerically estimated the inflow flux of terrestrial grass, which is the main floating macro-debris, into Tokyo Bay from April 2008 to March 2009 based on a two-way particle-tracking model and an inverse method applying a Lagrange multiplier. In the estimation, we used surface current velocities derived by high-frequency ocean radar and the quantity of grass collected by clean-up vessels which are operated daily in the bay. At least 2115 m(3) yr(-1) of the grass flowed into the bay annually, and the contribution of a flood event to the inflow flux of grass was larger than that of the inflow flux of freshwater. We show that 39% of the annual inflow flux of grass into the bay was collected, and 61% flowed out of the bay or sank to the seabed. The numerical estimation in this study will be useful to establish a system for predicting patches of floating macro-debris in the bay, and to evaluate the effects of river development or clean-up along river banks and flood plains in the upper reaches. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ecss.2013.09.005

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/kaigan.69.I_436

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/jscejhe.69.I_769

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

We have developed a technique for detecting the pixels of colored macro plastic debris (plastic pixels) using photographs taken by a webcam installed on Sodenohama beach, Tobishima Island, japan. The technique involves generating color references using a uniform color space (CIELUV) to detect plastic pixels and removing misdetected pixels by applying a composite image method. This technique demonstrated superior performance in terms of detecting plastic pixels of various colors compared to the previous method which used the lightness values in the CIELUV color space. We also obtained a 10-month time series of the quantity of plastic debris by combining a projective transformation with this technique. By sequential monitoring of plastic debris quantity using webcams, it is possible to clean up beaches systematically, to clarify the transportation processes of plastic debris in oceans and coastal seas and to estimate accumulation rates on beaches. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.marpolbul.2012.06.006

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本海洋学会沿岸海洋研究部会  

短波海洋レーダによる観測結果を用いた中立粒子実験に基づき,東シナ海を対象として開発された双方向粒子追跡法とラグランジュ未定乗数法による逆推定法の東京湾への適用性を確認した.特に水平拡散係数が流入源と流入量の推定精度に及ぼす影響について詳細に検討した.その結果,流入源位置の推定精度が10km以内,流入量の推定精度は0.9から1.6倍程度であることが明らかとなり,これら推定方法の東京湾への適用性が確認できた.真値に対して過大な水平拡散係数を計算に使用すると中立粒子の拡散スケールが実際よりも大きくなるため間違った流入源位置を特定する可能性が高くなる.流入量についても真値に対して過大な水平拡散係数を与えると同様な理由から流入量は過大に推定される.しかしながら,その影響の度合いは線形ではなく,真値に対して2倍程度の水平拡散係数を計算に用いれば推定精度は1.6倍程度,真値に対して1オーダー大きい水平拡散係数を用いた場合でも推定精度は6から7倍程度である.

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その他リンク： http://dl.ndl.go.jp/info:ndljp/pid/10578331

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/kaigan.68.I_196

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/kaigan.68.I_1471

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD  

Signals from the tsunami waves induced by the March 11, 2011 moment magnitude (M-w) 9.0 Tohoku-Oki earthquake and from subsequent resonances were detected as radial velocity variability by a high-frequency ocean surface radar (HF radar) installed on the eastern coast of the Kii Channel, at a range of about 1000 km from the epicenter along the eastern to southern coasts of Honshu Island. A time-distance diagram of band-passed (9-200 min) radial velocity along the beam reveals that the tsunami waves propagated from the continental shelf slope to the inner channel as progressive waves for the first three waves, and then natural oscillations were excited by the waves; and that the direction of the tsunami wave propagation and the axis of the natural oscillations differed from that of the radar beam. In addition, spectral analyses of the radial velocities and sea surface heights obtained in the channel and on the continental shelf slope suggest complex natural oscillation modes excited by the tsunami waves.
The major advantage of the HF radars as tsunami detection is early warning as the tsunami is still far offshore. There is no doubt on this importance beside still technical and operational studies are needed. Our results adds a new role of the HF radars to measure the detailed surface current fields with high spatiotemporal resolution toward understanding detailed processes of resonant response to tsunami waves in coastal regions. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ecss.2011.08.009

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

This study attempts to establish a system for hindcasting/forecasting the quantity of litter reaching a beach using an ocean circulation model, a two-way particle tracking model (PTM) to find litter sources, and an inverse method to compute litter outflows at each source. Twelve actual beach survey results, and satellite and forecasted wind data were also used. The quantity of beach litter was hindcasted/forecasted using a forward in-time PTM with the surface currents computed in the ocean circulation model driven by satellite-derived/forecasted wind data. Outflows obtained using the inverse method was given for each source in the model. The time series of the hindcasted/forecasted quantity of beach litter were found consistent with the quantity of beach litter determined from sequential webcam images of the actual beach. The accuracy of the model, however, is reduced drastically by intense winds such as typhoons which disturb drifting litter motion. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.marpolbul.2010.10.011

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER METEOROLOGICAL SOC  

The dependence of wind-driven current (WDC) on wind stress direction in a small semienclosed, homogeneous rotating basin is investigated using a linear steady-state analytical model based on Ekman solutions. The model is applicable to the middle of the basin (midbasin), and the current is driven by a constant wind stress of an arbitrary direction. The WDC is made up of wind stress-driven current (WSDC) and pressure-driven current (PDC) components. The laterally varying water depth of the basin confines the total volume transport in the longitudinal direction while the wind stress-driven volume transport changes direction according to the wind stress direction. Therefore, the pressure-driven volume transport or, equivalent, the pressure gradient depends on the wind stress direction: the relationship between the pressure gradient and the wind stress is anisotropic. As a result, the midbasin WDC is also dependent on the wind stress direction. The dependence varies according to the lateral position and Ekman number E. For large E (small rotation), the longitudinal volume transport is generally proportional to the longitudinal wind stress component. Hence, the ratio of the volume transport driven by the wind stress of direction theta (theta &gt; 0) to that driven by the longitudinal wind stress (theta = 0) becomes cos theta. For small E (large rotation), the ratio becomes larger than cos theta. The extent to which each component of wind stress contributes to the generation of the pressure gradient to satisfy no-net-longitudinal and no-lateral transports is determined by a wind stress-pressure gradient transformation matrix, whose components depend on the lateral position and E.

DOI： 10.1175/2010JPO4363.1

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記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）   出版者・発行元：日本海洋学会  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：COASTAL EDUCATION & RESEARCH FOUNDATION  

Trans-boundary pollution is carried by currents and other flows. Litter from river basins flow into the sea, and currents and winds spread them along the coast. In Japan, many citizen groups, community based organizations, fishermen, divers, national and local governments, CBO and an international NGO have continued to clean up beaches, riverbanks and the sea bottom for some decades. Most of these activities are voluntary, but the costs accrued by local governments progressively multiplied. Beach and river litter have become serious social problems. Therefore, scientific and systematic countermeasures, multi-sectoral collaboration and international collaboration are essential.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

The mechanism of a characteristic sea level response (barotropic coastal ocean response) to wind field fluctuation around the tip of the Izu Peninsula observed during the middle of December 2000 to the middle of January 2001 was investigated based on three types of numerical experiments using the Princeton Ocean Model with various parameters. The response was characterized by the relaxation of sea level falling (rising) during eastward upwelling (westward downwelling) favorable wind regime. Analyses of quasi-realistic numerical model results in terms of the vertically integrated momentum balances and vorticity balance for the barotropic mode revealed that: 1) development/abatement of two anomalous circulations generated around the tip of the Izu Peninsula controls the sea level response through the acceleration/deceleration of a quasi-geostrophic barotropic coastal current between the circulations; 2) nonlinear vorticity advection by the Kuroshio Current and by the coastal current, coupled with vorticity diffusion, decelerates the quasi - geostrophic coastal current in the latter half of the wind regimes, which induces the relaxation of sea level rise/fall. The results of the quasi-realistic numerical experiment suggest that an analysis of the vorticity balance for the barotropic mode contributes to a better understanding of sea level responses to wind in coastal regions with strong currents and complex topography. In addition, a numerical experiment with idealized spatially uniform density stratification and a quasi-realistic wind field shows that if the Kuroshio Current had been shifted far offshore from the Izu Peninsula during the observation period, westward propagating continental shelf waves would have controlled the coastal sea level response.

DOI： 10.1007/s10872-008-0051-z

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記述言語：日本語   出版者・発行元：日本海洋学会  

有明海湾奥部における低塩分・高クロロフィルa濃度の表層水塊の挙動をCTD・漂流ブイ・HFレーダー・衛星画像観測により調査した。クロロフィルa濃度が高い低塩分表層水塊は,海面下わずか1m程度の厚さしか持たないが,その下の層とは異なった収束・発散構造を持っていた。この薄い表層水塊中の収束・発散構造はクロロフィルa濃度と有意な相関を持っていた。有明海の赤潮発生規模が1998年以降大規模化した理由を明らかにするためには,この薄い表層低塩分・高クロロフィルa濃度水塊の挙動特性を明らかにする必要がある。The characteristic behavior of surface water with low salinity and high chlorophyll a concentration in the head of Ariake Bay, was elucidated by intensive field observations using CTD, drifting buoys, HF radars and satellite images. Such surface water mass has only 1m thickness and has a different divergence/convergence character from that in the lower layer. Such a divergence/convergence character has a close relation to the chlorophyll a concentration, that is, the high chlorophyll a concentration area coincides with the surface convergence area.

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その他リンク： http://id.nii.ac.jp/1141/00046590/

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

The Kyushu Regional Development Bureau, Ministry of Land, Infrastructure, Transport and Tourism has placed four High-Frequency Oceanic Radar (HF radar) at the Ariake Sea since 2005. The system named "The Ariake Sea current and ocean wave information system" provides the real-time information on surface currents and waves on the Internet.<BR>This paper presents the results of the comprehensive investigations on (1) the accuracy of HF radar observation, (2) the expansion of the current observation area, and (3) the improvement of the ocean wave observation. These inclusive studies come to the conclusions that the accuracy of ocean radar was verified satisfactory, and the expected improvements of the system for measuring currents as well as waves were successfully achieved.

DOI： 10.2208/prooe.24.849

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

The Kyushu Regional Development Bureau, Ministry of Land, Infrastructure and Transport has placed four High-Frequency Oceanic Radar System (HF radar) at the Ariake Sea with the aim of regenerating environmental condition, and has observed the surface current and ocean wave situations since 2005.<BR>The paper presents (1) the result of study for precision of HF radar observation, (2) the real-time informing system by internet named "The Ariake Sea current and ocean waves information system", and (3) the development of "The sea garbage movement prediction system" utilized the surface current observation information by the system with the aims of the improving the sea garbage collecting service by the Advanced Anti-Pollution Vessel "KAIKI" as well as the progress of the installing the system. As result of the development, the precision is verified appropriately, and the system has been operated since April, 2007.

DOI： 10.2208/prooe.23.709

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記述言語：英語   掲載種別：論文集(書籍)内論文   出版者・発行元：Springer Netherlands  

In Tokyo Bay (Figure 1), the river discharge into the head of the bay gives rise to horizontal density gradients that lead to an estuarine circulation (Nakayama, 2005) as shown in chapter of "Circulation Phenomena in Tokyo Bay". If the oceanic water, i.e. the Kuroshio warm water, approaching to the bay and it is denser than the bay bottom water, then a classical estuarine circulation prevails whereby there is an outflow of bay waters at the surface and an inflow of oceanic water in the lower layer. However, fluctuations of the circulations in the bay can occur on time scales ranging from a few days to a few months due to the effects of climate and/or Kuroshio current fluctuations in the time scales. As a result, the depth at which oceanic water intrudes is also though to vary with oceanic and climate conditions. Yanagi et al. (1989) measured the water quality at the mouth of Tokyo Bay. They suggested that a three-layer circulation may exists whereby the Kuroshio water flows into the middle layer of the bay where the water density is the same, while highly turbid water flows out from the bay in the surface layer and lower layer. If this hypothesis is correct, then the inflow of oceanic water into the middle layer should have a significant effect on the behavior of the hypoxic water mass that develops in the lower layer of the bay during the summer. In September 1998, the intrusion of oceanic water into the middle layer of Tokyo Bay occurred intermittently. At this time, Hinata et al. (2001) used ADCP (Acoustic Doppler Current Profiler) observations and water quality observations to take direct measurements of the flow structures inside the bay and the heat/material flux between the bay and ocean. This chapter revisits the observations of Hinata et al. (2001) to describe the three-dimensional flow structures inside the bay and the heat and material flux between the bay and ocean that occur when oceanic water intrudes into the middle layer inside the bay during the summer. (figure presented).

DOI： 10.1007/1-4020-3655-8_5

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記述言語：英語   掲載種別：論文集(書籍)内論文   出版者・発行元：Springer Netherlands  

This study demonstrates the existence of an ecological network of short-necked clam larvae in Tokyo Bay. It also shows that the whole Tokyo Bay ecosystem may be improved if suitable spawning grounds, even if they are small, are conserved and restored. Thus, our strategy for zoning the primary implementation area in the Tokyo Bay Restoration Plan is justified. It should be noted that this paper has only introduced the fate of pelagic larvae in one spawning case. Further observations and numerical studies will be needed to clarify how the advection of pelagic larvae contributes to the reproduction of shortnecked clams. It will also be necessary to study how pelagic short-necked clam larvae respond to factors such as water temperature and salinity, the temporal variation of their specific gravity, and to add these results in the pelagic shortnecked clam larvae model. Beside this uncertainty, inherent in any ecosystem model, this study demonstrates the importance of an ecological network in Tokyo Bay. © 2006 Springer.

DOI： 10.1007/1-4020-3655-8_3

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER GEOPHYSICAL UNION  

The mechanisms of the periodic Kuroshio warm water intrusion (KWWI) into Sagami Bay through the Oshima West Channel (OWC) and the fluctuation of the current field in the bay were investigated using high-frequency oceanic radar observation data, satellite imagery, and meteorological data. During the period from 15 December 2000 to 16 January 2001 the Kuroshio took a nonlarge meander path, looping south around the Kii Peninsula and then turning sharply north toward the Izu Peninsula (IP). Kuroshio warm water (KWW) then flowed into Sagami Bay periodically through the OWC on a synoptic timescale of 8-11 days. Statistical analysis of the data indicated that the occurrence of the KWWI and the variability in the Kuroshio front were highly coherent with wind velocity field fluctuations corresponding to the passage of cyclones across northern Japan. When southward to southwestward winds dominated in and around Sagami Bay, the Kuroshio front approached the southern coast of the IP, and then the KWW strongly intruded into the bay through the OWC. When eastward to northeastward winds prevailed, the front moved offshore about 10-20 km, ending the KWWI. The distances of the Kuroshio front movements were consistent with the internal radius of the deformation estimated from conductivity-temperature-depth data collected off the IP, suggesting that the Kuroshio front movement was induced by the onshore-offshore surface Ekman transport associated with the wind velocity field regime shift corresponding to the passage of cyclones. In addition, examination of the vorticity dynamics in the northern part of the bay based on radar-derived surface current data indicated that the cyclonic circulation generated in the bay was enhanced due to the transport of the positive relative vorticity by the KWWI plus the horizontal convergence accompanied by the stretching of the vorticity.

DOI： 10.1029/2004JC002300

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記述言語：日本語   出版者・発行元：日本海洋学会沿岸海洋研究部会  

東京湾において最も支配的な流れの一つであるM2潮流の空間分布をHFレーダー観測によって求めた.HFレーダーと超音波式流速計観測結果から求めたM2潮流楕円を比較した結果,潮流楕円の精度は観測海域とHFレーダーとの距離やビーム交差角度の影響を強く受けることが明らかとなった.これはHFレーダー視線方向の調和定数に誤差が含まれていたためである.4台のHFレーダー観測結果を同時に調和解析することによって,現時点での湾内におけるほぼ妥当なM2潮流分布を得ることができた.このことは,東京湾全域における潮流分布を同時に精度良く把握するためには,すくなくとも4局以上のHFレーダーが必要であることを示唆している.M2潮流の位相は,湾内のほぼ全域で60-70°の範囲であるが,富津岬沖で20-40°程度位相が進んでいる.また,既往の研究結果に見られるような湾の西側に比べて湾の東側で位相が進んでいる様子は,本解析結果には明確な形では現れなかった.

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その他リンク： http://dl.ndl.go.jp/info:ndljp/pid/10578082

記述言語：日本語   出版者・発行元：日本プランクトン学会  

The majority of the benthos are pelagic in their larval stages. The short-necked clam, Ruditapes philippinarum, which is widely distributed on sandy tidal flats across Japan and is a commercially important shellfish, has a planktonic larval stage, which lasts 2 to 3 weeks after hatching. In this stage, most clam larvae are able to disperse over wide areas with the currents and then settle on new habitats on other shores. In the case of Tokyo Bay, reclamation of the tidal flats and shallows has brought a marked decrease in the harvest of the clam. To recover the clam populations on the shores of Tokyo Bay, the creation of suitable habitats for the clam and the preservation of their environment are very important. We also need to understand how local populations of the clam are maintained through wide dispersal ranges over tidal flats during the larval stages. In this paper, we show the dynamics of larval dispersal of the clam in Tokyo Bay introducing the results of field plankton surveys conducted by the National Institute for Land and Infrastructure Management Ministry of Land and the National Research Institute of Fisheries and Environment of Inland Sea in 2001. The spatial distribution of the larval abundance of the clam was investigated at 65 stations along the entire range of Tokyo Bay on August 2, 6, 10 and October 15, 19, 23, in 2001. Identification of the larvae of the clam was performed using the monoclonal antibody technique. A large number of small D-shaped larvae were found shortly after hatching in the sea waters around the Banzu, Futtu, and Sanmaizu-Haneda in August and the Sanbanze, Sanmaizu-Haneda, and Kanazawa areas in October indicating that spawning populations in these areas probably contributed greatly to the larval supply in the bay. Moreover, the smallest size larvae also occurred abundantly around the Yokohama and Chiba port areas, suggesting that these port regions may play an important role in the transport of larvae into Tokyo Bay.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER HEIDELBERG  

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 I 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 I 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.

DOI： 10.1007/s10236-003-0055-6

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

発行月不明

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記述言語：日本語   出版者・発行元：日本プランクトン学会  

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その他リンク： http://agriknowledge.affrc.go.jp/RN/2010701535

記述言語：日本語   出版者・発行元：生物研究社  

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：The Oceanographic Society of Japan  

相模湾に設置した11Fレーダーの観測結果に基づいて,大島西水道から黒潮系噴水が流人した場合の相模湾表層循環流の空間構造とその変動特性について検討した。本観測期間中,黒潮流路は基本的に非大蛇行離岸流路型であったが,典型的大蛇行流路型に近い流路をとる場合,黒潮系噴水が大島西水道から湾内へ流入し,湾中央に反時計回り,大島北東部に時計回りの循環流が形成される。この時,黒潮前線は北東-南西方向の風により生じるエクマン輸送の働きによって,10日前後の周期で小規模な(10～15km)離接岸を繰り返す。この小規模な離接岸は大島西水道からの暖水流入の強度を変化させ,その結果,湾内のニつの循環流も10日前後の周期で盛衰を繰り返す。さらに,噴水流人が強化され循環流が発達した場合には,噴水の一部が東京湾湾口部にまで到達し,湾口部において沿岸フロントが形成される。

DOI： 10.5928/kaiyou.12.167

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/jscej.2001.684_93

CiNii Books

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 土木学会  

1997年12月から1998年4月にかけて東京湾湾口部で現地観測を行い, 黒潮系暖水波及時における湾口部周辺海域の海洋構造を明らかにすることを試みた. その結果, 観測期間中確認された暖水波及時には湾口部表層において明確な水温, 塩分フロントが形成されていたが, 従来いわれている熱塩フロント構造と異なり, 暖水が内湾水の下層に潜り込みながら湾内へ侵入する形のフロント構造であったことが明らかとなった. これは, 黒潮系暖水が内湾水よりも重かったことによるが, 外洋水が侵入する水深は, 湾内密度の鉛直分布と外洋水密度の相対的な関係で決まっている. また, この暖水波及時には, 冬季における平均的な値に比べて約5倍の大きさの外洋から湾内への熱フラックスが存在し, この熱フラックスの要因として, 残差流の水平シア成分の寄与が大きいことが明らかとなった.

DOI： 10.2208/jscej.2000.656_221

CiNii Books

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.45.986

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.45.416

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.45.421

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.44.391

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.44.1076

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.44.401

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.44.456

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.43.406

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.43.391

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.42.1226

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J-GLOBAL

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記述言語：日本語  

J-GLOBAL

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J-GLOBAL

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

CiNii Books

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記述言語：日本語  

J-GLOBAL

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記述言語：日本語  

J-GLOBAL

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記述言語：日本語   出版者・発行元：国土技術政策総合研究所  

CiNii Books

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J-GLOBAL

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記述言語：日本語   出版者・発行元：国土技術政策総合研究所  

CiNii Books

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記述言語：日本語   出版者・発行元：日本海洋学会沿岸海洋研究部会  

人工的な海岸漂着物(海ゴミ)に関する既往研究を概説するとともに,海ゴミ漂着量のウェブカメラを用いたモニタリング技術や,発生源の逆推定技術の開発に取り組んだ研究プロジェクトについて紹介する.また,効率のよい海ゴミ回収事業や,海洋学研究者の海ゴミ問題への積極的な関与を提案する.

CiNii Books

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その他リンク： http://id.nii.ac.jp/1141/00048007/

記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

CiNii Books

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J-GLOBAL

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記述言語：日本語   出版者・発行元：国土技術政策総合研究所  

CiNii Books

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記述言語：日本語  

CiNii Books

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記述言語：日本語  

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記述言語：日本語   出版者・発行元：国土技術政策総合研究所  

CiNii Books

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記述言語：日本語   出版者・発行元：海洋気象学会  

CiNii Books

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.47.426

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記述言語：日本語   出版者・発行元：公益社団法人 土木学会  

典型的な閉鎖性水域である東京湾と開放性沿岸域である鹿島灘の年間表層水温変動過程の大局的な特徴を定量的に把握するために, 閉鎖性がより強くかつほぼ同様な気象条件下にある霞ヶ浦も含めた形での長期連続観測データに基づく比較解析を行った. その結果, 1) 鹿島灘海岸域では移流による熱輸送が年間を通して水温変動に寄与するのに対し, 霞ヶ浦では大気側との熱交換によって水温変動がほぼ規定されていること, 2) 夏季の東京湾湾奥部においては, 7日以上の時間スケールでは水表面を通した大気側からの熱輸送によって表層混合層内の水温変動が支配されており, 夏季の表層水温が霞ヶ浦のそれとほぼ同じになること, 3) 冬季では, 湾口を通した外洋からの熱輸送が湾内の水温変動に大きく寄与すること, などが明らかになった.

DOI： 10.2208/jscej.2000.656_239

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出版者・発行元：土木学会  

DOI： 10.2208/proce1989.47.396

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DOI： 10.2208/jscej.2000.642_87

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記述言語：日本語   出版者・発行元：東京工業大学工学部土木工学科  

CiNii Books

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.46.1001

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DOI： 10.2208/proce1989.46.396

CiNii Books

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記述言語：日本語   出版者・発行元：Japan Society of Civil Engineers  

DOI： 10.2208/proce1989.46.451

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記述言語：日本語  

J-GLOBAL

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記述言語：日本語  

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記述言語：日本語   出版者・発行元：日本流体力学会  

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記述言語：日本語  

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記述言語：日本語  

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開催年月日： 2024年9月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2024年9月

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開催年月日： 2024年2月

記述言語：日本語   会議種別：シンポジウム・ワークショップ パネル（指名）  

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開催年月日： 2023年12月

記述言語：英語   会議種別：口頭発表（招待・特別）  

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記述言語：英語   会議種別：口頭発表（招待・特別）  

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開催年月日： 2023年8月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

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開催年月日： 2022年2月 - 2022年3月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2022年2月 - 2022年3月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2021年10月

記述言語：英語   会議種別：シンポジウム・ワークショップ パネル（指名）  

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開催年月日： 2021年9月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2021年9月

記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2021年7月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2021年5月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2021年5月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2021年5月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2020年7月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2020年7月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2019年5月

記述言語：英語   会議種別：口頭発表（招待・特別）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：ポスター発表  

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記述言語：英語   会議種別：口頭発表（一般）  

© 2016 IEICE. A tsunami generated by 'The 2011 off the Pacific coast of Tohoku Earthquake' was observed by two high frequency ocean surface radars (HF radars) and four tide gauges installed on Ise Bay. The tsunami wave arrived initially at 16:50 was observed by tide gauge which is installed on the mouth of the Bay. This wave propagation was also observed by HF radars installed on the inner part of the Bay. Therefore, these observations were considered to be correlated. The result of spectral analysis, the tsunami wave had energy with period bands of 120-140, 60-90 and 30-40 min. In comparison to the previous study suggest that these 60-90 and 30-40 min periods oscillations were attributed to the tsunami source fault.

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：ポスター発表  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：ポスター発表  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：ポスター発表  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：シンポジウム・ワークショップ パネル（公募）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（招待・特別）  

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記述言語：日本語   会議種別：口頭発表（招待・特別）  

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記述言語：英語   会議種別：口頭発表（一般）  

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To investigate the characteristics of flow field in the coastal buffer zone (C.B.Z.), velocity measurements in a field were performed both in non-stratified and stratified conditions. The results of the data analysis have shown that in the non-stratified condition wind action, together with tidal motion, may induce unexpectedly large velocity even near the bottom with the magnitude beyond the threshold of the sediment movement, suggesting that the appreciable sediment transport may be caused by these wind-driven currents in C.B.Z.. In the stratified condition, it is revealed that internal tides with baroclinic velocity fluctuation may dominate the cross-shore exchanging motion of water mass.

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：ポスター発表  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：ポスター発表  

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執筆者：本人以外 

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