Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10872-014-0254-4

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/2013JC009464

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1029/2012JC008162

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1029/2008JC005150

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1175/2007JPO3750.1

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Oceanography  

Enhanced autumn transport via the Tsushima Warm Current (TWC) has been reported to increase winter rainfall along Japan’s northern coast. However, observations reveal a significantly weakened correlation after 2006. Although enhanced transport via the Eastern channel of the Tsushima Strait affects rainfall by enhancing latent heat flux along Japan’s northern coast, the role of oceanic flows in varying sea-surface temperatures has weakened since 2006. Stronger northwesterly winds co-occur with enhanced surface heat loss that overwhelms the impact of the TWC. Our findings imply that atmospheric conditions should be considered when using TWC transport as a precursor for winter rainfall.

DOI： 10.1007/s10872-024-00734-8

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Language：English   Publisher：Springer  

Enhanced autumn transport via the Tsushima Warm Current (TWC) has been reported to increase winter rainfall along Japan’s northern coast. However, observations reveal a significantly weakened correlation after 2006. Although enhanced transport via the Eastern channel of the Tsushima Strait affects rainfall by enhancing latent heat flux along Japan’s northern coast, the role of oceanic flows in varying sea-surface temperatures has weakened since 2006. Stronger northwesterly winds co-occur with enhanced surface heat loss that overwhelms the impact of the TWC. Our findings imply that atmospheric conditions should be considered when using TWC transport as a precursor for winter rainfall.

CiNii Research

Publishing type：Research paper (scientific journal)   Publisher：Journal of Oceanography  

The Japan Sea shows a much stronger warming of long-term sea surface temperature (SST) than surrounding oceans. The warming trend possesses a meridionally alternating zonal band pattern, with weak trends along the paths of the Japan Sea Throughflow and strong trends in the remaining interior region. Using idealized models of the Japan Sea Throughflow and atmospheric heating, this study examines the process behind the formation of such spatial patterns in the SST trend. We find that zonal band structures form in a flat rectangular coastline model, and heat budget analysis shows that horizontal heat transport, due to throughflow, reduces the warming effect created by the surface heat flux. A weak SST trend appears around the jet, while a strong SST trend appears elsewhere. Bathymetric effects are also examined using a model with realistic coastline settings. The location of the western boundary current stabilizes, and the coastal branch begins to disconnect from the Japanese coastline toward the north, allowing a more stable SST warming region to form in the southern interior region. Lagrangian particle tracking experiments confirm that a weak (strong) SST trend corresponds to a short (long) residence time, and eddies in the Japan Sea prolong the residence time in interior regions. The model results suggest that the accumulation time of surface heating is essential to the spatial distribution of the long-term SST warming trend.

DOI： 10.1007/s10872-024-00723-x

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Repository Public URL： https://hdl.handle.net/2324/7178740

Language：English   Publisher：Springer  

The Japan Sea shows a much stronger warming of long-term sea surface temperature (SST) than surrounding oceans. The warming trend possesses a meridionally alternating zonal band pattern, with weak trends along the paths of the Japan Sea Throughflow and strong trends in the remaining interior region. Using idealized models of the Japan Sea Throughflow and atmospheric heating, this study examines the process behind the formation of such spatial patterns in the SST trend. We find that zonal band structures form in a flat rectangular coastline model, and heat budget analysis shows that horizontal heat transport, due to throughflow, reduces the warming effect created by the surface heat flux. A weak SST trend appears around the jet, while a strong SST trend appears elsewhere. Bathymetric effects are also examined using a model with realistic coastline settings. The location of the western boundary current stabilizes, and the coastal branch begins to disconnect from the Japanese coastline toward the north, allowing a more stable SST warming region to form in the southern interior region. Lagrangian particle tracking experiments confirm that a weak (strong) SST trend corresponds to a short (long) residence time, and eddies in the Japan Sea prolong the residence time in interior regions. The model results suggest that the accumulation time of surface heating is essential to the spatial distribution of the long-term SST warming trend.

CiNii Research

Language：Others   Publishing type：Research paper (scientific journal)   Publisher：Journal of Geophysical Research: Oceans  

[Abstract] / The impact of a large shallow semi-enclosed lagoon on freshwater exchange across an inlet channel is investigated using an idealized numerical model. Lagoons are often found between a river mouth and the ocean; we focus on those where the river discharge rate is small and the inlet channel is narrower and deeper than the lagoon. Tides generate freshwater and oceanic-water plumes across the channel; a stratified freshwater plume forms in the ocean from the late ebb to early flood phase, while a vertically well-mixed oceanic-water plume forms in the lagoon from the late flood to early ebb phase. The shallow depth of the lagoon increases the flow speed of the oceanic-water plume, which results in the formation of a sharp and vertically well-mixed salinity front within the lagoon. When this front moves toward the ocean during the ebb phase, vertical mixing increases where the bathymetry deepens and freshwater encounters oceanic water below. Without a dredged bottom slope, the impact of mixing would be greatly reduced within the shallow lagoon and channel, as the shallow depth would limit the subsurface intrusion of oceanic water. The narrow channel further causes the flow to converge and accelerate, enhancing both internal shear-driven and bottom boundary-layer mixing at the channel and increasing freshwater plume thickness where it enters the ocean. Sensitivity experiments showed that the role of tidal pumping in freshwater exchange across the channel increases when the lagoon area and tidal mixing increase and when the estuarine Richardson number decreases. / / [Plain Language Summary] / Freshwater outflows from estuaries play an important role in supporting coastal marine environments. Large shallow lagoons are often found at river mouths with an inlet channel; this study uses idealized numerical model experiments to investigate how lagoons affect freshwater exchange across an inlet channel where the river discharge rate is low. Freshwater exchange often results in estuarine circulation wherein freshwater enters the ocean near the surface, while oceanic water intrudes into the estuary near the bottom, with weaker circulation expected for a shallow environment. We find that large lagoons force strong tidal flows across the channel, enhancing mixing between freshwater and oceanic water, especially during the ebb phase. Due to the fast flow generated over the shallow lagoon, mixing occurs when freshwater in the lagoon moves across a sloping bottom and interacts with oceanic water below. Freshwater outflow becomes thicker and tidally pulsed plumes are generated. / / [Key Points] / • A large lagoon with a narrow inlet induces strong tidal pumping across the channel, in turn generating plumes in the ocean and lagoon / • Mixing is enhanced as the sharp salinity front formed within the shallow lagoon moves across the sloping bottom during the ebb phase / • Tidal pumping induces more freshwater exchange than estuarine circulation when the estuarine Richardson number is below unity

DOI： 10.1029/2023JC019755

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Language：Others   Publishing type：Research paper (scientific journal)   Publisher：American Geophysical Union (AGU)  

Previous studies have shown the presence of strong mesoscale eddy activities in the Indonesian Seas and their influence on the transport and water mass properties of the Indonesian Throughflow (ITF), a mean flow from the Pacific Ocean to the Indian Ocean through the Indonesian Archipelago. This study explores the effects of these eddy activities, or high-frequency flow variability (HFFV), on residence time and pathway of the ITF by conducting Lagrangian particle tracking experiments using a velocity field from an eddy-resolving ocean general circulation model. Particles are released at key locations in the western and eastern routes of the ITF and tracked both backward and forward in time. To assess the effects of flow variability that has a time scale longer than a day but shorter than a month, the definition of HFFV in this study, we conduct parallel experiments using daily and monthly averaged velocity fields. Particle trajectories reveal the contrasting circulation characteristics of the Sulawesi and Banda Seas. HFFV in the Sulawesi Sea (in the western route) is high, causing water to circulate longer over a broader area. The longer residence time in the Sulawesi Sea helps the upwelling of the inflowing Pacific waters, especially the intermediate water masses, to rise above 300 m at the Makassar Strait, and also has the potential to allow mixing processes to modify the water mass properties of the ITF. In contrast, HFFV is much lower in the Banda Sea and has minimal effects on the ITF.

DOI： 10.1029/2022jc019610

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

CiNii Research

Language：Others  

Decadal vision in oceanography 2021: Coastal oceans

DOI： 10.5928/kaiyou.30.5_87

Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

Language：English   Publishing type：Research paper (scientific journal)  

A long-term increasing trend in the transport of the Japan Sea Throughflow is observed from sea-level differences across the Tsushima Strait. Tidal gauge observations show sea level at Hakata, Japan, increasing at a higher rate than that at Busan, Korea. Numerical modeling results suggest that this increasing trend is forced by a northward shift in the Kuroshio axis. As the Kuroshio axis moves northward, sea level along the southern coast of Japan increases. The signal then propagates anticyclonically along the coast as topographic Rossby waves and Kelvin waves, raising sea level and, thus, increasing transport through the Tsushima Strait.

DOI： 10.1007/s10872-020-00563-5

Language：English   Publishing type：Research paper (scientific journal)  

A quasi-global eddying ocean hindcast simulation using a new version of our model, called OFES2 (Ocean General Circulation Model for the Earth Simulator version 2), was conducted to overcome several issues with unrealistic properties in its previous version, OFES. This paper describes the model and the simulated oceanic fields in OFES2 compared with OFES and also observed data. OFES2 includes a sea-ice model and a tidal mixing scheme, is forced by a newly created surface atmospheric dataset called JRA55-do, and simulated the oceanic fields from 1958 to 2016. We found several improvements in OFES2 over OFES: smaller biases in the global sea surface temperature and sea surface salinity as well as the water mass properties in the Indonesian and Arabian seas. The time series of the Niño3.4 and Indian Ocean Dipole (IOD) indexes are somewhat better in OFES2 than in OFES. Unlike the previous version, OFES2 reproduces more realistic anomalously low sea surface temperatures during a positive IOD event. One possible cause of these improvements in El Niño and IOD events is the replacement of the atmospheric dataset. On the other hand, several issues remained unrealistic, such as the pathways of the Kuroshio and Gulf Stream and the unrealistic spreading of salty Mediterranean overflow. Given the worldwide use of the previous version and the improvements presented here, the output from OFES2 will be useful in studying various oceanic phenomena with broad spatiotemporal scales.

DOI： 10.5194/gmd-13-3319-2020

Repository Public URL： http://hdl.handle.net/2324/4479735

Language：English   Publishing type：Research paper (scientific journal)  

A quasi-global eddying ocean hindcast simulation using a new version of our model, called OFES2 (Ocean General Circulation Model for the Earth Simulator version 2), was conducted to overcome several issues with unrealistic properties in its previous version, OFES. This paper describes the model and the simulated oceanic fields in OFES2 compared with OFES and also observed data. OFES2 includes a sea-ice model and a tidal mixing scheme, is forced by a newly created surface atmospheric dataset called JRA55-do, and simulated the oceanic fields from 1958 to 2016. We found several improvements in OFES2 over OFES: smaller biases in the global sea surface temperature and sea surface salinity as well as the water mass properties in the Indonesian and Arabian seas. The time series of the Nino3.4 and Indian Ocean Dipole (IOD) indexes are somewhat better in OFES2 than in OFES. Unlike the previous version, OFES2 reproduces more realistic anomalously low sea surface temperatures during a positive IOD event. One possible cause of these improvements in El Nino and IOD events is the replacement of the atmospheric dataset. On the other hand, several issues remained unrealistic, such as the pathways of the Kuroshio and Gulf Stream and the unrealistic spreading of salty Mediterranean overflow. Given the worldwide use of the previous version and the improvements presented here, the output from OFES2 will be useful in studying various oceanic phenomena with broad spatiotemporal scales.

DOI： 10.5194/gmd-13-3319-2020

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1029/2019WR026412

Language：Japanese   Publishing type：Research paper (other academic)  

Language：English   Publishing type：Research paper (scientific journal)  

Spatial and temporal information on oceanic flow is fundamental to oceanography and crucial for marine-related social activities. This study attempts to describe the short-term surface flow variation in the area south of the Lombok Strait in the northern summer using the hourly Himawari-8 sea surface temperature (SST). Although the uncertainty of this temperature is relatively high (about 0.6 °C), it could be used to discuss the flow variation with high spatial resolution because sufficient SST differences are found between the areas north and south of the strait. The maximum cross-correlation (MCC) method is used to estimate the surface velocity. The Himawari-8 SST clearly shows Flores Sea water intruding into the Indian Ocean with the high-SST water forming a warm thermal plume on a tidal cycle. This thermal plume flows southward at a speed of about 2 m/s. The Himawari-8 SST indicates a southward flow from the Lombok Strait to the Indian Ocean, which blocks the South Java Current flowing eastward along the southern coast of Nusa Tenggara. Although the satellite data is limited to the surface, we found it useful for understanding the spatial and temporal variations in the surface flow field.

DOI： 10.3390/rs11121491

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/rs11121491

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1029/2018JC014707

Language：English   Publishing type：Research paper (scientific journal)  

The Indonesian Seas receive one of the largest amounts of rainfall around the globe. Part of this freshwater disperses to the Indian Ocean through the Indonesian Throughflow (ITF), the Pacific and Indian interocean exchange flow, making the Indonesian Seas a major source of freshwater, and plays an important part of the global hydrological cycle. By using a Lagrangian particle tracking model, we examine the pathways behind the dispersion of freshwater that the Indonesian Seas receive through precipitation. The model suggests that the dispersion from the near-surface water of the Indonesian Seas occurs in about 6 months, primarily through advection to the surrounding seas, followed by evaporation, entrainment, and vertical mixing. The Lombok Strait and the Timor Strait are the major outflowing straits, and the freshwater exiting through these straits are found to originate from limited areas and seasons. The sources for the Lombok Strait outflow are the Java Sea precipitated freshwater during boreal fall and winter, while the sources for the Timor Strait outflow are the Flores-Banda Seas and Arafura Sea precipitated freshwater during winter and spring. Mixing with the thermocline water is found to occur when the monsoonal winds induce upwelling events in winter and summer, along the shelf breaks and steep coastlines surrounding the Flores-Banda Seas. Vertical mixing provides a pathway for the surface freshwater to enter the ITF thermocline, and our model suggests that it is the Java Sea precipitated freshwater during winter that is entering the ITF thermocline along its main pathway.

DOI： 10.1029/2018JC014707

Language：English   Publishing type：Research paper (scientific journal)  

The impact of internal tidal mixing on the volume transport of the Indonesian Throughflow (ITF) is examined by a comparison of high-resolution quasi-global ocean simulations with and without a tidal mixing scheme. The ITF transport is found to be increased in the presence of tidal mixing. This is because tidal mixing decreases the density within and below the lower thermocline and increases the buoyancy of the water column. As a result, the surface pressure and the sea surface height (SSH) are raised. The magnitude of the SSH increase is larger for the tropical Pacific Ocean than for the other basins, possibly because many islands exist in the tropical Pacific and tidal mixing is effective around their shallow and rough topographies. Since SSH increases more in the tropical Pacific than in the Indian Ocean, the pressure difference between the two basins is enhanced and thus the ITF transport is strengthened.

DOI： 10.1029/2018GL078040

Language：English   Publishing type：Research paper (scientific journal)  

The role of topographically induced form drag on the channel flows through the East/Japan Sea

DOI： 10.1029/2018JC013903

Language：English   Publishing type：Research paper (scientific journal)  

The dynamics responsible for the East/Japan Sea throughflow are examined using the Finite Volume Coastal Ocean Model. Existing ocean data assimilation models (Δx ~10 km) present overestimates of the volume transport through the Tsugaru Strait, and the outflow partitioning between the Tsugaru and Soya/La Perouse Straits also differs depending on the models. We find that this overestimate occurs when the form drag that is induced by detailed bottom topographic features in the Tsugaru Strait is not adequately resolved. A range of experiments with different horizontal resolutions in the Korea/Tsushima, Tsugaru, and Soya/La Perouse Straits were conducted to examine how detailed bottom topographic features in these three straits may affect the throughflow. We find that the volume transport is highly sensitive to the spatial resolution at the Tsugaru Strait but not at the Korea/Tsushima and Soya/La Perouse Straits. The high-resolution experiment showed a decreased outflow through the Tsugaru Strait and a reduction in the model bias. The outflow through the Soya/La Perouse Strait increased, while the inflow through the Korea/Tsushima Strait remained relatively unchanged. Additional experiments with modified topography further indicated that the abrupt change of the topography located at the upstream side of the Tsugaru Strait plays an important role in the outflow partitioning of the East/Japan Sea throughflow.

DOI： 10.1029/2018JC013903

Language：English   Publishing type：Research paper (scientific journal)  

An Increase of the Indonesian Throughflow by Internal Tidal Mixing in a High‐Resolution Quasi‐Global Ocean Simulation
©2018. American Geophysical Union. All Rights Reserved. The impact of internal tidal mixing on the volume transport of the Indonesian Throughflow (ITF) is examined by a comparison of high-resolution quasi-global ocean simulations with and without a tidal mixing scheme. The ITF transport is found to be increased in the presence of tidal mixing. This is because tidal mixing decreases the density within and below the lower thermocline and increases the buoyancy of the water column. As a result, the surface pressure and the sea surface height (SSH) are raised. The magnitude of the SSH increase is larger for the tropical Pacific Ocean than for the other basins, possibly because many islands exist in the tropical Pacific and tidal mixing is effective around their shallow and rough topographies. Since SSH increases more in the tropical Pacific than in the Indian Ocean, the pressure difference between the two basins is enhanced and thus the ITF transport is strengthened.

DOI： 10.1029/2018GL078040

Language：English   Publishing type：Research paper (scientific journal)  

The mechanisms of spring phytoplankton blooms are investigated from a Lagrangian framework by using a Lagrangian NPZD model that can track the movement and transfers of nutrient parcels in a turbulent environment. The model reveals that the onset of spring blooms depends on the cumulative euphotic age, which is the total time that inorganic nutrient is exposed to light before the photosynthetic conversion to phytoplankton biomass. A spring bloom, defined as a tenfold increase of near-surface phytoplankton, occurs when this cumulative euphotic age is approximately mu(-1)(eff).ln?10, where mu(eff) is the effective growth rate in the euphotic layer, regardless of the underlying mechanism. If the turbulent layer depth is shallower than the critical depth and turbulence is strong, nutrient parcels accumulate enough light exposure through multiple entries to the sun-lit zone near the surface. If turbulence is weak, as that considered in the critical turbulence theory, the accumulation of the light exposure depends on the residence time of the nutrients parcels near the surface. The spectral shape of the cumulative euphotic age can clearly distinguish these two modes of spring blooms. The spectrum shows a peak at the theoretical growth timescale when multiple entries become important, while it shows a maximum near age zero that decays with age when the near-surface residence time becomes important. Mortality increases the cumulative euphotic age necessary for a bloom but does not affect the spectral shape, suggesting that it does not alter the primary mechanism behind the accumulation of cumulative euphotic age.

DOI： 10.1002/2017JC013383

Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

A numerical model for the marginal seas

DOI： 10.14943/lowtemsci.74.67

Language：English   Publishing type：Research paper (scientific journal)  

This article focuses on the physical and dynamical processes of the marginal seas of the Western Pacific. The nature of the circulation regimes and their interconnectivity are discussed in detail, with emphasis on individual basins. In addition to the Kuroshio and its variability in the North Pacific, the circulation regimes in the South China Sea and Indonesian Seas are presented for an overall view of the circulation system. These circulations play important roles in regional ocean dynamics and global climate variations such as the El Niño/Southern Oscillation.

DOI： 10.1142/9789814696623_0006

Language：English   Publishing type：Research paper (scientific journal)  

This article focuses on the physical and dynamical processes of the marginal seas of the Western Pacific. The nature of the circulation regimes and their interconnectivity are discussed in detail, with emphasis on individual basins. In addition to the Kuroshio and its variability in the North Pacific, the circulation regimes in the South China Sea and Indonesian Seas are presented for an overall view of the circulation system. These circulations play important roles in regional ocean dynamics and global climate variations such as the El Niño/Southern Oscillation.

DOI： 10.1142/9789814696623_0006

Language：English   Publishing type：Research paper (scientific journal)  

The mechanism responsible for the annual cycle of the flow through the straits of the Japan Sea is investigated using a two-layer model. Observations show maximum throughflow from summer to fall and minimum in winter, occurring synchronously at the three major straits: Tsushima, Tsugaru, and Soya Straits. This study finds the subpolar winds located to the north of Japan as the leading forcing agent, which first affects the Soya Strait rather than the Tsushima or Tsugaru Straits. The subpolar winds generate baroclinic Kelvin waves along the coastlines of the subpolar gyre, affect the sea surface height at the Soya Strait, and modify the flow through the strait. This causes barotropic adjustment to occur inside the Japan Sea and thus affect the flow at the Tsugaru and Tsushima Straits almost synchronously. The barotropic adjustment mechanism explains well why the observations show a similar annual cycle at the three straits. The annual cycle at the Tsugaru Strait is further shown to be weaker than that in the other two straits based on frictional balance around islands, that is, frictional stresses exerted around an island integrate to zero. In the Tsugaru Strait, the flows induced by the frictional integrals around the northern (Hokkaido) and southern (Honshu) islands are in opposite directions and tend to cancel out. Frictional balance also suggests that the annual cycle at the Tsugaru Strait is likely in phase with that at the Soya Strait because the length scale of the northern island is much shorter than that of the southern island.

DOI： 10.1175/JPO-D-15-0075.1

Language：Others  

Oceanic fronts and jets around Japan: A review
© The Oceanographic Society of Japan and Springer Japan 2016. This article reviews progress in our understanding of oceanic fronts around Japan and their roles in air–sea interaction. Fronts associated with the Kuroshio and its extension, fronts within the area of the Kuroshio-Oyashio confluence, and the subtropical fronts are described with particular emphasis on their structure, variability, and role in air–sea interaction. The discussion also extends to the fronts in the coastal and marginal seas, the Seto Inland Sea and Japan Sea. Studies on oceanic fronts have progressed significantly during the past decade, but many of these studies focus on processes at individual fronts and do not provide a comprehensive view. Hence, one of the goals of this article is to review the oceanic fronts around Japan by describing the processes based on common metrics. These metrics focus primarily on surface properties to obtain insights into air–sea interactions that occur along oceanic fronts. The basic characteristics derived for each front (i.e., metrics) are then presented as a table. We envision that many of the coupled ocean-atmosphere global circulation models in the coming decade will represent oceanic fronts reasonably well, and it is hoped that this review along with the table of metrics will provide a useful benchmark for evaluating these models.

DOI： 10.1007/978-4-431-56053-1_1

Language：English  

This article reviews progress in our understanding of oceanic fronts around Japan and their roles in air–sea interaction. Fronts associated with the Kuroshio and its extension, fronts within the area of the Kuroshio-Oyashio confluence, and the subtropical fronts are described with particular emphasis on their structure, variability, and role in air–sea interaction. The discussion also extends to the fronts in the coastal and marginal seas, the Seto Inland Sea and Japan Sea. Studies on oceanic fronts have progressed significantly during the past decade, but many of these studies focus on processes at individual fronts and do not provide a comprehensive view. Hence, one of the goals of this article is to review the oceanic fronts around Japan by describing the processes based on common metrics. These metrics focus primarily on surface properties to obtain insights into air–sea interactions that occur along oceanic fronts. The basic characteristics derived for each front (i.e., metrics) are then presented as a table. We envision that many of the coupled ocean-atmosphere global circulation models in the coming decade will represent oceanic fronts reasonably well, and it is hoped that this review along with the table of metrics will provide a useful benchmark for evaluating these models.

DOI： 10.1007/978-4-431-56053-1_1

Language：English  

This article reviews progress in our understanding of oceanic fronts around Japan and their roles in air-sea interaction. Fronts associated with the Kuroshio and its extension, fronts within the area of the Kuroshio-Oyashio confluence, and the subtropical fronts are described with particular emphasis on their structure, variability, and role in air-sea interaction. The discussion also extends to the fronts in the coastal and marginal seas, the Seto Inland Sea and Japan Sea. Studies on oceanic fronts have progressed significantly during the past decade, but many of these studies focus on processes at individual fronts and do not provide a comprehensive view. Hence, one of the goals of this article is to review the oceanic fronts around Japan by describing the processes based on common metrics. These metrics focus primarily on surface properties to obtain insights into air-sea interactions that occur along oceanic fronts. The basic characteristics derived for each front (i.e., metrics) are then presented as a table. We envision that many of the coupled ocean-atmosphere global circulation models in the coming decade will represent oceanic fronts reasonably well, and it is hoped that this review along with the table of metrics will provide a useful benchmark for evaluating these models.

DOI： 10.1007/s10872-015-0283-7

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1175/JCLI-D-14-00479.1

Language：English   Publishing type：Research paper (scientific journal)  

Regional sea level trend and variability in the Pacific Ocean have often been considered to be induced by low-frequency surface wind changes. This study demonstrates that significant sea level trend and variability can also be generated by eddy momentum flux forcing due to time-varying instability of the background oceanic circulation. Compared to the broad gyre-scale wind-forced variability, the eddy-forced sea level changes tend to have subgyre scales and, in the North Pacific Ocean, they are largely confined to the Kuroshio Extension region (30 degrees-40 degrees N, 140 degrees-175 degrees E) and the Subtropical Countercurrent (STCC) region (18 degrees-28 degrees N, 130 degrees-175 degrees E). Using a two-layer primitive equation model driven by the ECMWF wind stress data and the eddy momentum fluxes specified by the AVISO sea surface height anomaly data, the relative importance of the wind-and eddy-forced regional sea level trends in the past two decades is quantified. It is found that the increasing (decreasing) trend south (north) of the Kuroshio Extension is due to strengthening of the regional eddy forcing over the past two decades. On the other hand, the decreasing (increasing) sea level trend south (north) of the STCC is caused by the decadal weakening of the regional eddy momentum flux forcing. These decadal eddy momentum flux changes are caused by the background Kuroshio Extension and STCC changes in connection with the Pacific decadal oscillation (PDO) wind pattern shifting from a positive to a negative phase over the past two decades.

DOI： 10.1175/JCLI-D-14-00479.1

Language：English   Publishing type：Research paper (scientific journal)  

This study presents a new approach for simulating surface runoff, river flow, and oceanic flow. Hydrological-ocean coupled models often stitch the two models at the river mouth because they typically differ in formulation, dynamically and dimensionally. An isopycnal-layered model is shown to naturally couple hydrological and oceanic processes seamlessly with the use of a single dynamical core. Numerical experiments show the high discharge event of the Abukuma River in Japan during Typhoon Roke with realistic river flows and freshwater plumes in the ocean. The time series of the river discharge rates also match well with observations from upstream to downstream.

DOI： 10.1007/s10872-014-0254-4

Language：English   Publishing type：Research paper (scientific journal)  

A new mechanism for driving the water mass exchange between the Okhotsk Sea and the North Pacific is presented. This exchange flow originates from the East Kamchatka Current (EKC), a western boundary current of the subpolar gyre, and occurs through the two deepest straits of the Kuril island chain, the Kruzenshtern and Bussol straits. An inflow toward the Okhotsk Sea occurs at the northern Kruzenshtern strait and an outflow toward the North Pacific occurs at the southern Bussol strait. By using the Kelvin's Circulation theorem around the island between the two straits, we show that the transport of the exchange flow entering the Okhotsk Sea is determined such that the frictional stresses around the island exerted by the bifurcated EKC integrate to zero. This forcing mechanism is different from the dynamical framework of the widely used Island rule. Both an analytical analysis and 1.5-layer model experiments demonstrate that the strait width, lateral viscosity, and island geometry are controlling parameters for the exchange flow transport because they affect the magnitude and length scales of the frictional stresses. Inertia of the EKC decreases the exchange flow by enhancing the frictional stress along the northern coast of the Kuril island. Model experiments with realistic topography further reveal that while the steep continental slopes have minor impact on the exchange flow transport, the subsurface peninsula located east of the Kuril island works to decrease the exchange flow by altering the length scale of the frictional stresses and enabling the EKC to flow past the island.

DOI： 10.1002/2013JC009464

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.5194/bg-10-4911-2013

Language：English   Publishing type：Research paper (scientific journal)  

The mechanism behind the dispersion of radionuclides released from the Fukushima Dai-ichi Nuclear Power Plant on March 2011 is investigated using a numerical model. This model is a Lagrangian particle tracking-ocean circulation coupled model that is capable of solving the movement and migration of radionuclides between seawater, particulates, and bottom sediments. Model simulations show the radionuclides dispersing rapidly into the interior of the North Pacific once they enter a meso-scale eddy. However, some radionuclides also remain near the coast, with spatial distribution depending strongly on the oceanic circulation during the first month after the release. Major adsorption to bottom sediments occurs during this first month and many of these radionuclides remain on the sea floor once they are adsorbed. Model results suggest that weak offshore advection during the first month will increase the adsorption of radionuclides to bottom sediments and decelerate the dispersion to the open ocean. If vertical mixing is weak, however, fewer radionuclides reach the sea floor and adsorb to bottom sediments. More radionuclides will then quickly disperse to the open ocean. © Author(s) 2013.

DOI： 10.5194/bg-10-4911-2013

Language：English   Publishing type：Research paper (other academic)  

Language：English   Publishing type：Research paper (scientific journal)  

A numerical model is used to investigate how the Indonesian Throughflow and tidal mixing are affecting the seasonal cycle of the sea surface temperature (SST) in the Indonesian Seas. The SST in these seas is considered to play a major role on the development of the Australian Summer Monsoon. Based on a quantitative assessment of the heat budget, the Indonesian Throughflow is found to affect the SST in the western Indonesian Seas primarily during Austral summer. The Throughflow advects the warm water from the Pacific and maintains the warm SST when the Northwestern Monsoonal wind induces coastal upwelling along the northern side of the Nusa Tenggara and cools the SST. Such balance is supported by observations. The hydrographic sections show the isotherms tilting upward toward the northern coast of the Nusa Tenggara when satellite observations show slight decrease of the SST in the region. Tidal mixing is found to cool the SST during summer the most. This is because the Northwest Monsoonal wind induces coastal upwelling near where strong tidal mixing above seamount occurs and brings the tidally well-mixed upper thermocline water to the surface. The surface Ekman flow also spreads this cool water around the Banda Sea where tidal mixing does not occur. The impact of tidal mixing on the SST is also found to come largely from that occurring above seamounts. The impact of tidal mixing on the continental shelves is limited to shelf-breaks because cold subsurface water is necessary for enhanced vertical mixing to cool the SST.

DOI： 10.1029/2012JC008162

Language：English   Publishing type：Research paper (other academic)  

Ocean currents and vortices play an important role in transferring heat, salt or carbon as well as atmospheric circulation. With advances in supercomputing technology, high-resolution large-scale simulation study has been focused in the field of ocean science. However, it is difficult to intuitively understand characteristic features defined as multivariable hiding in the high-resolution dataset. In order to obtain scientific knowledge from large-scale simulation data, it is important to effectively extract and to efficiently express the characteristic feature. The aim of this study is how to efficiently extract and how to effectively visualize ocean currents which affect the heat transportation. In this research, new multi-dimensional transfer function to emphasis the ocean currents and vortices is proposed. Furthermore, multivariate analyses to extract such features are developed. This presentation describes the methodologies and experimental results of these methods. Evaluation of visualization results and feedback to the parameter optimization will be also reported.

DOI： 10.1109/SC.Companion.2012.263

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1175/2011JPO4571.1

Language：English   Publishing type：Research paper (scientific journal)  

The impact of open oceanic processes on the Antarctic Bottom Water (AABW) outflows is investigated using a numerical model with a focus on outflows that occur through deep channels. A major branch of the AABW outflow is known to occur as an overflow from the Filchner Depression to the Weddell Sea through a deep channel a few hundred kilometers wide and a sill roughly 500 m deep. When this overflow enters the Weddell Sea, it encounters the Antarctic Slope Front (ASF) at the shelf break, a density front commonly found along the Antarctic continental shelf break. The presence of an AABW outflow and the ASF create a v-shaped isopycnal structure across the shelf break, indicating an interaction between the overflow and oceanic processes. Model experiments show the overflow transport to increase significantly when an oceanic wind stress increases the depth of the ASF. This enhancement of overflow transport occurs because the channel walls allow a pressure gradient in the along-slope direction to exist and the overflow transport is geostrophically controlled with its ambient oceanic water at the shelf break. Because the ASF is associated with a lighter water mass that reaches the depth close to that of the channel, an increase in its depth increases the density gradient across the shelf break and therefore the geostrophic overflow transport. The enhancement of overflow transport is also likely to result in a lighter overflow water mass, although such an adjustment of density likely occurs on a much longer time scale than the adjustment of transport.

DOI： 10.1175/2011JPO4571.1

Language：English   Publishing type：Research paper (scientific journal)  

We examine the seasonal mixed-layer temperature (MLT) and salinity (MLS) budgets in the Banda-Arafura Seas region (120-138A degrees E, 8-3A degrees S) using an ECCO ocean-state estimation product. MLT in these seas is relatively high during November-May (austral spring through fall) and relatively low during June-September (austral winter and the period associated with the Asian summer monsoon). Surface heat flux makes the largest contribution to the seasonal MLT tendency, with significant reinforcement by subsurface processes, especially turbulent vertical mixing. Temperature declines (the MLT tendency is negative) in May-August when seasonal insolation is smallest and local winds are strong due to the southeast monsoon, which causes surface heat loss and cooling by vertical processes. In particular, Ekman suction induced by local wind stress curl raises the thermocline in the Arafura Sea, bringing cooler subsurface water closer to the base of the mixed layer where it is subsequently incorporated into the mixed layer through turbulent vertical mixing; this has a cooling effect. The MLT budget also has a small, but non-negligible, semi-annual component since insolation increases and winds weaken during the spring and fall monsoon transitions near the equator. This causes warming via solar heating, reduced surface heat loss, and weakened turbulent mixing compared to austral winter and, to a lesser extent, compared to austral summer. Seasonal MLS is dominated by ocean processes rather than by local freshwater flux. The contributions by horizontal advection and subsurface processes have comparable magnitudes. The results suggest that ocean dynamics play a significant part in determining both seasonal MLT and MLS in the region, such that coupled model studies of the region should use a full ocean model rather than a slab ocean mixed-layer model.

DOI： 10.1007/s10236-010-0374-3

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10236-010-0374-3

Language：English   Publishing type：Research paper (scientific journal)  

Diagnostics performed with twentieth-century (1861-2000) ensemble integrations of the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.1 (CM2.1) suggest that, during the developing phase, El Niño events that co-occur with the Indian Ocean Dipole Zonal Mode (IODZM; class 1) are stronger than those without (class 2). Also, during class 1 events coherent sea surface temperature (SST) anomalies develop in the Indonesian seas that closely follow the life cycle of IODZM. This study investigates the effect of these regional SST anomalies (equatorial Indian Ocean and Indonesian seas) on the amplitude of the developing El Niño. An examination of class 1 minus class 2 composites suggests two conditions that could lead to a strong El Niño in class 1 events: (i) during January, ocean-atmosphere conditions internal to the equatorial Pacific are favorable for the development of a stronger El Niño and (ii) during May-June, coinciding with the development of regional SST anomalies, an abrupt increase in westerly wind anomalies is noticeable over the equatorial western Pacific with a subsequent increase in thermocline and SST anomalies over the eastern equatorial Pacific. This paper posits the hypothesis that, under favorable conditions in the equatorial Pacific, regional SST anomalies may enable the development of a stronger El Niño. Owing to a wealth of feedbacks in CM2.1, solutions from a linear atmosphere model forced with May-June anomalous precipitation and anomalous SST from selected areas over the equatorial Indo-Pacific are examined. Consistent with our earlier study, the net Kelvin wave response to contrasting tropical Indian Ocean heating anomalies cancels over the equatorial western Pacific. In contrast, Indonesian seas SST anomalies account for about 60%-80% of the westerly wind anomalies over the equatorial western Pacific and also induce anomalous precipitation over the equatorial central Pacific. It is argued that the feedback between the precipitation and circulation anomalies results in an abrupt increase in zonal wind anomalies over the equatorial western Pacific. Encouraged by these results, the authors further examined the processes that cause cold SST anomalies over the Indonesian seas using an ocean model. Sensitivity experiments suggest that local wind anomalies, through stronger surface heat loss and evaporation, and subsurface upwelling are the primary causes. The present results imply that in coupled models, a proper representation of regional air-sea interactions over the equatorial Indo-Pacific warm pool may be important to understand and predict the amplitude of El Niño.

DOI： 10.1175/2010JCLI3396.1

Language：English   Publishing type：Research paper (scientific journal)  

Diagnostics performed with twentieth-century (1861-2000) ensemble integrations of the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.1 (CM2.1) suggest that, during the developing phase, El Nino events that co-occur with the Indian Ocean Dipole Zonal Mode (IODZM; class 1) are stronger than those without (class 2). Also, during class 1 events coherent sea surface temperature (SST) anomalies develop in the Indonesian seas that closely follow the life cycle of IODZM. This study investigates the effect of these regional SST anomalies (equatorial Indian Ocean and Indonesian seas) on the amplitude of the developing El Nino.
An examination of class 1 minus class 2 composites suggests two conditions that could lead to a strong El Nino in class 1 events: (i) during January, ocean-atmosphere conditions internal to the equatorial Pacific are favorable for the development of a stronger El Nino and (ii) during May-June, coinciding with the development of regional SST anomalies, an abrupt increase in westerly wind anomalies is noticeable over the equatorial western Pacific with a subsequent increase in thermocline and SST anomalies over the eastern equatorial Pacific. This paper posits the hypothesis that, under favorable conditions in the equatorial Pacific, regional SST anomalies may enable the development of a stronger El Nino.
Owing to a wealth of feedbacks in CM2.1, solutions from a linear atmosphere model forced with May-June anomalous precipitation and anomalous SST from selected areas over the equatorial Indo-Pacific are examined. Consistent with our earlier study, the net Kelvin wave response to contrasting tropical Indian Ocean heating anomalies cancels over the equatorial western Pacific. In contrast, Indonesian seas SST anomalies account for about 60%-80% of the westerly wind anomalies over the equatorial western Pacific and also induce anomalous precipitation over the equatorial central Pacific. It is argued that the feedback between the precipitation and circulation anomalies results in an abrupt increase in zonal wind anomalies over the equatorial western Pacific.
Encouraged by these results, the authors further examined the processes that cause cold SST anomalies over the Indonesian seas using an ocean model. Sensitivity experiments suggest that local wind anomalies, through stronger surface heat loss and evaporation, and subsurface upwelling are the primary causes. The present results imply that in coupled models, a proper representation of regional air-sea interactions over the equatorial Indo-Pacific warm pool may be important to understand and predict the amplitude of El Nino.

DOI： 10.1175/2010JCLI3396.1

Language：English   Publishing type：Research paper (scientific journal)  

The response of the Indonesian Seas to the monsoonal winds is investigated using a regional ocean model with an emphasis on understanding the mechanisms behind the observed seasonal sea surface temperature (SST) variability. Understanding the seasonal SST variability in the Indonesian Seas is crucial for understanding tropical climate variability since atmospheric deep convection is located directly above these seas. Our model results suggest that the monsoonal winds play a dominant role in creating the spatial SST variability and are responsible for inducing about half of the basin-averaged SST variability. The remaining half is found to be caused by conditions in surface heating, which is brought about by radiation and atmospheric temperature and humidity. The northwesterly wind during Austral summer is roughly uniform over the basin so wind mixing occurs roughly uniformly and no significant spatial SST variability is forced. The southeasterly wind during Austral winter, on the other hand, has a significant spatial variation with a maximum wind speed located in the middle of the basin. This spatial variability causes Ekman upwelling and downwelling in the north and south of the Indonesian Seas, respectively, and establishes a cold SST region in the northeast. The presence of the shallow shelf region in the east is also found critical to the formation of this cold SST event. Without the shelf, lateral advection of warm water from the west will trap the cold SST region to the eastern boundary. Copyright 2009 by the American Geophysical Union.

DOI： 10.1029/2008JC005150

Language：English   Publishing type：Research paper (scientific journal)  

The response of the Indonesian Seas to the monsoonal winds is investigated using a regional ocean model with an emphasis on understanding the mechanisms behind the observed seasonal sea surface temperature (SST) variability. Understanding the seasonal SST variability in the Indonesian Seas is crucial for understanding tropical climate variability since atmospheric deep convection is located directly above these seas. Our model results suggest that the monsoonal winds play a dominant role in creating the spatial SST variability and are responsible for inducing about half of the basin-averaged SST variability. The remaining half is found to be caused by conditions in surface heating, which is brought about by radiation and atmospheric temperature and humidity. The northwesterly wind during Austral summer is roughly uniform over the basin so wind mixing occurs roughly uniformly and no significant spatial SST variability is forced. The southeasterly wind during Austral winter, on the other hand, has a significant spatial variation with a maximum wind speed located in the middle of the basin. This spatial variability causes Ekman upwelling and downwelling in the north and south of the Indonesian Seas, respectively, and establishes a cold SST region in the northeast. The presence of the shallow shelf region in the east is also found critical to the formation of this cold SST event. Without the shelf, lateral advection of warm water from the west will trap the cold SST region to the eastern boundary.

DOI： 10.1029/2008JC005150

Language：English   Publishing type：Research paper (scientific journal)  

Marginal sea overflows and the overlying upper ocean are coupled in the vertical by two distinct mechanisms by an interfacial mass flux from the upper ocean to the overflow layer that accompanies entrainment and by a divergent eddy flux associated with baroclinic instability. Because both mechanisms tend to be localized in space, the resulting upper ocean circulation can be characterized as a beta plume for which the relevant background potential vorticity is set by the slope of the topography, that is, a topographic beta plume.
The entrainment-driven topographic beta plume consists of a single gyre that is aligned along isobaths. The circulation is cyclonic within the upper ocean (water columns are stretched). The transport within one branch of the topographic beta plume may exceed the entrainment flux by a factor of 2 or more.
Overflows are likely to be baroclinically unstable, especially near the strait. This creates eddy variability in both the upper ocean and overflow layers and a flux of momentum and energy in the vertical. In the time mean, the eddies accompanying baroclinic instability set up a double-gyre circulation in the upper ocean, an eddy-driven topographic beta plume. In regions where baroclinic instability is growing, the momentum flux from the overflow into the upper ocean acts as a drag on the overflow and causes the overflow to descend the slope at a steeper angle than what would arise from bottom friction alone.
Numerical model experiments suggest that the Faroe Bank Channel overflow should be the most prominent example of an eddy-driven topographic beta plume and that the resulting upper-layer transport should be comparable to that of the overflow. The overflow-layer eddies that accompany baroclinic instability are analogous to those observed in moored array data. In contrast, the upper layer of the Mediterranean overflow is likely to be dominated more by an entrainment-driven topographic beta plume. The difference arises because entrainment occurs at a much shallower location for the Mediterranean case and the background potential vorticity gradient of the upper ocean is much larger.

DOI： 10.1175/2008JPO3934.1

Language：English   Publishing type：Research paper (scientific journal)  

Marginal sea overflows and the overlying upper ocean are coupled in the vertical by two distinct mechanisms by an interfacial mass flux from the upper ocean to the overflow layer that accompanies entrainment and by a divergent eddy flux associated with baroclinic instability. Because both mechanisms tend to be localized in space, the resulting upper ocean circulation can be characterized as a b plume for which the relevant background potential vorticity is set by the slope of the topography, that is, a topographic b plume. The entrainment-driven topographic b plume consists of a single gyre that is aligned along isobaths. The circulation is cyclonic within the upper ocean (water columns are stretched). The transport within one branch of the topographic b plume may exceed the entrainment flux by a factor of 2 or more. Overflows are likely to be baroclinically unstable, especially near the strait. This creates eddy variability in both the upper ocean and overflow layers and a flux of momentum and energy in the vertical. In the time mean, the eddies accompanying baroclinic instability set up a double-gyre circulation in the upper ocean, an eddy-driven topographic b plume. In regions where baroclinic instability is growing, the momentumflux from the overflow into the upper ocean acts as a drag on the overflow and causes the overflow to descend the slope at a steeper angle than what would arise from bottom friction alone. Numerical model experiments suggest that the Faroe Bank Channel overflow should be the most prominent example of an eddy-driven topographic b plume and that the resulting upper-layer transport should be comparable to that of the overflow. The overflow-layer eddies that accompany baroclinic instability are analogous to those observed in moored array data. In contrast, the upper layer of the Mediterranean overflow is likely to be dominated more by an entrainment-driven topographic b plume. The difference arises because entrainment occurs at a much shallower location for the Mediterranean case and the background potential vorticity gradient of the upper ocean is much larger.

DOI： 10.1175/2008JPO3934.1

Language：English   Publishing type：Research paper (scientific journal)  

The oceanic response to overflows is explored using a two-layer isopycnal model. Overflows enter the open ocean as dense gravity currents that flow along and down the continental slope. While descending the slope, overflows typically double their volume transport by entraining upper oceanic water. The upper oceanic layer must balance this loss of mass, and the resulting convergent flow produces significant vortex stretching. Overflows thus represent an intense and localized mass and vorticity forcing for the upper ocean. In this study, simulations show that the upper ocean responds to the overflow-induced forcing by establishing topographic beta plumes that are aligned more or less along isobaths and that have a transport that is typically a few times larger than that of the overflows. For the topographic beta plume driven by the Mediterranean overflow, the occurrence of eddies near Cape St. Vincent, Portugal, allows the topographic beta plume to flow across isobaths. The modeled topographic beta-plume circulation forms two transatlantic zonal jets that are analogous to the Azores Current and the Azores Countercurrent. In other cases ( e. g., the Denmark Strait overflow), the same kind of circulation remains trapped along the western boundary and hence would not be readily detected.

DOI： 10.1175/2007JPO3750.1

Event date： 2018.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Honolulu, HI   Country：United States  

Event date： 2018.5

Language：Japanese  

Venue：幕張メッセ   Country：Japan  

Event date： 2018.5

Language：Japanese  

Venue：幕張メッセ   Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学   Country：Japan  

Event date： 2018.5

Language：English  

Venue：Portland   Country：United States  

Event date： 2018.5

Language：English   Presentation type：Oral presentation (general)  

Venue：La Paz   Country：Mexico  

Event date： 2024.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：北海道大学   Country：Japan  

Event date： 2024.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：横浜国立大学   Country：Japan  

Event date： 2024.2

Language：English   Presentation type：Oral presentation (general)  

Venue：New Orleans   Country：United States  

Event date： 2024.2

Language：English   Presentation type：Oral presentation (general)  

Venue：New Orleans   Country：United States  

Event date： 2023.11

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：Online   Country：India  

Event date： 2023.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台国際センター   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学   Country：Japan  

Event date： 2023.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Singapore   Country：Singapore  

Event date： 2023.5 - 2024.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2023.5 - 2024.5

Language：Japanese  

Venue：幕張メッセ   Country：Japan  

Event date： 2023.5 - 2024.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2023.5 - 2024.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2023.5 - 2024.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2023.5 - 2024.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋大学   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋大学   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2022.5

Language：English   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2022.2

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：United States  

Event date： 2022.2

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：United States  

Event date： 2022.2

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：United States  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋大学   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.12

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：United States  

Event date： 2020.12

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：United States  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.11

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2020.7

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2020.7

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2020.7

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2020.7

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2020.2

Language：English  

Venue：San Diego   Country：United States  

Event date： 2020.2

Language：English  

Venue：San Diego   Country：United States  

Event date： 2020.2

Language：English  

Venue：San Diego   Country：United States  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2019.12

Language：Japanese  

Venue：幕張   Country：Japan  

Event date： 2019.12

Language：Japanese  

Venue：幕張   Country：Japan  

Event date： 2019.12

Language：Japanese  

Venue：富山   Country：Japan  

Event date： 2019.12

Language：Japanese  

Venue：富山   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2019.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学大気海洋研究所・国際沿岸海洋研究センター   Country：Japan  

Event date： 2019.3

Language：English   Presentation type：Oral presentation (general)  

Venue：高雄、台湾   Country：Japan  

Event date： 2019.2 - 2019.3

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2018.9

Language：English   Presentation type：Oral presentation (general)  

Venue：名古屋大学   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京海洋大学   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京海洋大学   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京海洋大学   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京海洋大学   Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2018.5

Language：English   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：Univeristy of Tasmania   Country：Australia  

Event date： 2018.5

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：名古屋大学   Country：Japan  

Event date： 2018.5

Language：English  

Venue：幕張メッセ   Country：Japan  

Event date： 2018.5

Language：English  

Venue：幕張メッセ   Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2018.5

Language：Japanese  

Venue：仙台国際センター   Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台国際センター   Country：Japan  

Event date： 2018.5

Language：English  

Venue：Portland   Country：United States  

Event date： 2018.5

Language：English   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2016.6

Language：English  

Venue：幕張メッセ   Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Venue：Yonsei University   Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Venue：Yonsei University   Country：Japan  

Type：Competition, symposium, etc. 

Type：Scientific advice/Review 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：4

Type：Competition, symposium, etc. 

Type：Scientific advice/Review 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：4

Type：Competition, symposium, etc. 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：4

Type：Competition, symposium, etc. 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：6

Type：Competition, symposium, etc. 

Number of participants：50

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：50

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：4

Number of peer-reviewed articles in Japanese journals：1

Type：Academic society, research group, etc. 

Type：Competition, symposium, etc. 

Number of participants：50

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：4

Number of peer-reviewed articles in Japanese journals：2

Type：Competition, symposium, etc. 

Number of participants：50

Type：Competition, symposium, etc. 

Number of participants：50

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：5

Number of peer-reviewed articles in Japanese journals：1

Proceedings of International Conference Number of peer-reviewed papers：0

Proceedings of domestic conference Number of peer-reviewed papers：0

Type：Competition, symposium, etc.