Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Shinichiro Kida Last modified date:2020.01.04

Associate Professor / Center for Oceanic and Atmospheric Research / Research Institute for Applied Mechanics

1. Shinichiro Kida, Kelvin J. Richards, Hideharu Sasaki, The Fate of Surface Freshwater Entering the Indonesian Seas, Journal of Geophysical Research: Oceans, 10.1029/2018JC014707, 2019.04, 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..
2. Naokazu Taniguchi, Shinichiro Kida, Yuji Sakuno, Hidemi Mutsuda, Fadli Syamsudin, Short-term variation of the surface flow pattern south of Lombok Strait observed from the Himawari-8 sea surface temperature, Remote Sensing, 10.3390/rs11121491, 11, 12, 2019.06, 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..
3. H. Sasaki, Shinichiro Kida, R. Furue, M. Nonaka, Y. Masumoto, An Increase of the Indonesian Throughflow by Internal Tidal Mixing in a High-Resolution Quasi-Global Ocean Simulation, Geophysical Research Letters, 10.1029/2018GL078040, 45, 16, 8416-8424, 2018.08, 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..
4. Sooyeon Han, Naoki Hirose, Shinichiro Kida, The Role of Topographically Induced Form Drag on the Channel Flows Through the East/Japan Sea, Journal of Geophysical Research, 10.1029/2018JC013903, 2018.08, 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..
5. Shinichiro Kida, Takamitsu Ito, A Lagrangian View of Phytoplankton blooms, Journal of Geophysical Research Oceans, 10.1002/2017JC013383, 2017.11.
6. Shinichiro Kida, The Annual Cycle of the Japan Sea Throughflow, JOURNAL OF PHYSICAL OCEANOGRAPHY, 10.1175/JPO-D-15-0075.1, 46, 1, 23-39, 2016.01.
7. Tangdong Qu, Tomoki Tozuka, Shinichiro Kida, Xinyu Guo, Yasumasa Miyazawa, Qinyu Liu, Western pacific and marginal sea processes, World Scientific Series on Asia-Pacific Weather and Climate, 10.1142/9789814696623_0006, 7, 151-186, 2016.01, 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..
8. Shinichiro Kida, Humio Mitsudera, Shigeru Aoki, Xinyu Guo, Shin Ichi Ito, Fumiaki Kobashi, Nobumasa Komori, Atsushi Kubokawa, Toru Miyama, Ryosuke Morie, Hisashi Nakamura, Tomohiro Nakamura, Hideyuki Nakano, Hajime Nishigaki, Masami Nonaka, Hideharu Sasaki, Yoshi N. Sasaki, Toshio Suga, Shusaku Sugimoto, Bunmei Taguchi, Koutarou Takaya, Tomoki Tozuka, Hiroyuki Tsujino, Norihisa Usui, Oceanic fronts and jets around Japan
A review, Hot Spots in the Climate System New Developments in the Extratropical Ocean-Atmosphere Interaction Research, 10.1007/978-4-431-56053-1_1, 1-30, 2016.01, 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..
9. Shinichiro Kida, H. Mitsudera, S. Aoki, X. Gu, S. Ito, F. Kobashi, N. Komori, A. Kubokawa, T. Miyama, R. Morie, H. Nakamura,, T. Nakamura, H. Nakano, H. Nishigaki, M. Nonaka,, H. Sasaki, Y.N. Sasaki, T. Suga, S. Sugimoto, B. Taguchi, K. Takaya, T. Tozuka, H. Tsujino, N. Usui, Oceanic fronts and jets around Japan: a review, JOURNAL OF OCEANOGRAPHY, 10.1007/s10872-015-0283-7, 71, 5, 469-497, 2015.10.
10. Bo Qiu, Shuming Chen, Lixin Wu, Shinichiro Kida, Wind- versus Eddy-Forced Regional Sea Level Trends and Variability in the North Pacific Ocean, JOURNAL OF CLIMATE, 10.1175/JCLI-D-14-00479.1, 28, 4, 1561-1577, 2015.02.
11. Shinichiro Kida, Yosuke Yamashiki, A layered model approach for simulating high river discharge events from land to the ocean, Journal of Oceanography, 10.1007/s10872-014-0254-4, 71, 1, 125-132, 2015.02.
12. Shinichiro Kida, Bo Qiu, An exchange flow between the Okhotsk Sea and the North Pacific driven by the East Kamchatka Current, Journal of Geophysical Research, Ocean, 10.1002/2013JC009464, 118, 2013.11.
13. Shinichiro Kida, Choi, Takahashi, The impact of oceanic circulation and phase transfer on the dispersion of radionuclides released from the Fukushima Dai-ichi Nuclear Power Plant, BIOGEOSCIENCES, 10.5194/bg-10-4911-2013, 10, 7, 4911-4925, 2013.07.
14. Shinichiro Kida, Susan Wijffels, The impact of the Indonesian Throughflow and tidal mixing on the summertime sea surface temperature in the western Indonesian Seas, JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 10.1029/2012JC008162, 117, 2012.09.
15. Daisuke Matsuoka, Fumiaki Araki, Shinichiro Kida, Hideharu Sasaki, Bunmei Taguchi, Visualization for high-resolution ocean general circulation model via multi-dimensional transfer function and multivariate analysis, 2012 SC Companion: High Performance Computing, Networking Storage and Analysis, SCC 2012 Proceedings - 2012 SC Companion: High Performance Computing, Networking Storage and Analysis, SCC 2012, 10.1109/SC.Companion.2012.263, 1466, 2012, 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..
16. Shinichiro Kida, The Impact of Open Oceanic Processes on the Antarctic Bottom Water Outflows, JOURNAL OF PHYSICAL OCEANOGRAPHY, 10.1175/2011JPO4571.1, 41, 10, 1941-1957, 2011.10.
17. D.J. Halkides, T. Lee, Shinichiro Kida, The mechanism controlling seasonal mixed layer temperature of the Indonesian Seas in an ECCO assimilation product, Ocean Dynamics, 10.1007/s10236-010-0374-3, 61, 481, 2011.02.
18. H. Annamalai, Shinichiro Kida, Jan Hafner, Potential impact of the tropical Indian Ocean-Indonesian seas on El Niño characteristics, Journal of Climate, 10.1175/2010JCLI3396.1, 23, 14, 3933-3952, 2010.07, 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..
19. Shinichiro Kida, K. J. Richards, Seasonal sea surface temperature variability in the Indonesian Seas, Journal of Geophysical Research, 10.1029/2008JC005150, 114, 6, 2009.06.
20. Shinichiro Kida, Jiayan Yang, James F. Price, Marginal sea overflows and the upper ocean interaction, Journal of Physical Oceanography, 10.1175/2008JPO3934.1, 39, 2, 387-403, 2009, 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..
21. Shinichiro Kida, James F. Price, Jiayan Yang, The upper-oceanic response to overflows
A mechanism for the Azores current, Journal of Physical Oceanography, 10.1175/2007JPO3750.1, 38, 4, 880-895, 2008.04.