Search Results 1-20 of 1364

  • Ensemble flood simulation for a small dam catchment in Japan using nonhydrostatic model rainfalls - Part 2: Flood forecasting using 1600-member 4D-EnVar-predicted rainfalls

    Kobayashi Kenichiro , Duc Le , Apip , Oizumi Tsutao , Saito Kazuo

    … approx. 70 km(2)) in Niigata, Japan, using a distributed rainfall-runoff model and rainfall ensemble forecasts. … The ensemble forecasts were given by an advanced four-dimensional, variational-ensemble assimilation system using the Japan Meteorological Agency nonhydrostatic model (4D-EnVar-NHM). …

    Natural Hazards and Earth System Sciences 20(3), 755-770, 2020-03-23

    IR 

  • Anatomical traits of Cryptomeria japonica tree rings studied by wavelet convolutional neural network

    Nakajima T , Kobayashi K , Sugiyama J

    … Tree ring analysis is an important field of science, and is vital in modeling the environmental response system of tree growth. … Therefore, to elucidate the sub-seasonal climatic response of softwood (Cryptomeria japonica), we investigate the use of a wavelet–convolutional neural network (CNN) model, which incorporates spectral information that is normally lost in conventional CNN models. …

    IOP Conference Series: Earth and Environmental Science (415), 2020-02

    IR 

  • Impact of latent heat flux modifications on the reproduction of a Madden–Julian oscillation event during the 2015 Pre-YMC campaign using a global cloud-system-resolving model

    Matsugishi Shuhei , Miura Hiroaki , Nasuno Tomoe , Satoh Masaki

    … <p>We show that a modification to the latent heat flux (LHF) formulation in Non-hydrostatic Icosahedral Atmospheric Model (NICAM) impacts the representation of a Madden–Julian oscillation (MJO) event during the Pre-Years of the Maritime Continent (Pre-YMC) field campaign in 2015. … This result indicates that increasing the LHF in the low wind speed region likely contributes to a more effective accumulation of moisture over the eastern MC region and consequently allows the MJO to pass over the MC in the model.</p> …

    SOLA, 2020

    J-STAGE 

  • Genesis and Maintenance Processes of a Quasi-Stationary Convective Band that Produced Record-Breaking Precipitation in Northern Kyushu, Japan on 5 July 2017

    KAWANO Tetsuya , KAWAMURA Ryuichi

    … The Weather and Research and Forecasting (WRF) model was used to perform numerical simulations and to clarify the genesis and maintenance processes of the convective band. … Trajectory and frontogenesis analyses showed that low-level confluent flows due to the blocking effects of a high pressure system located over the Sea of Japan were responsible for the formation, intensification, and sustenance of the convergence zone. …

    Journal of the Meteorological Society of Japan. Ser. II, 2020

    J-STAGE 

  • A Study of Environmental Geochemical Cycle between Atmosphere and Ocean : Potentials of Deposition of Atmospheric species to the Surface Marine Ecosystem  [in Japanese]

    TAKETANI Fumikazu

    … To better understand this process, we developed improved numerical models by combining an atmospheric regional chemical transport model (WRF-CMAQ) and a 3-D lower trophic-marine ecosystem model (NEMURO). …

    Vacuum and Surface Science 63(4), 165-170, 2020

    J-STAGE 

  • Location of the Preferred Region for Tropical Cyclogenesis in Strong Monsoon Trough Pattern over the Western North Pacific

    CAO Xi , WU Renguang , WEI Na , DAI Yifeng

    <p> We examined the processes of tropical cyclogenesis in strong monsoon trough pattern over the western North Pacific (WNP) using reanalysis data and numerical experiments. Composite analysis s …

    Journal of the Meteorological Society of Japan. Ser. II, 2020

    J-STAGE 

  • Projecting the Impact of Climate Change on Temperature, Precipitation, and Discharge in the Bago River Basin

    Myo Hnin Thiri , Zin Win Win , Shwe Kyi Pyar , San Zin Mar Lar Tin , Kawasaki Akiyuki , Acierto Ralph Allen

    … Linear scaling was used as the bias-correction method for ten general circulation models (GCMs) participating in the fifth phase of the Coupled Model Intercomparison Project. … The Hydrologic Engineering Center-Hydrologic Modeling System model is used to predict future discharge changes for the Bago River considering future average precipitation for all three future periods. …

    Journal of Disaster Research 15(3), 324-334, 2020

    J-STAGE 

  • Geoscientific model of a seafloor hydrothermal system associated with the formation of massive sulfide deposits  [in Japanese]

    Ishibashi Jun-ichiro , Urabe Tetsuro

    <p>金属資源の消費量が増加の一途をたどる中,将来の資源を海洋底に求めようとする動きが高まっている。海底熱水鉱床は,熱水が海底下を循環するシステムの作用で,亜鉛,鉛,銅などの硫化鉱物が沈殿して形成されるもので,鉱石中の金属濃集度が高いことから注目されている。我が国の大陸棚海域には,海底熱水系を伴う海底火山がこれまでにも数多く確認されており,金属資源のポテンシャルが高いことが期待できる。 …

    BUTSURI-TANSA(Geophysical Exploration) 73(0), 74-82, 2020

    J-STAGE 

  • Detection of small crustal deformation caused by slow slip events in southwest Japan using GNSS and tremor data

    Fujita Megumi , Nishimura Takuya , Miyazaki Shin'ichi

    … We stacked daily Global Navigation Satellite System (GNSS) displacement increments in southwest Japan to detect the cumulative crustal deformation accompanying non-volcanic low-frequency tremors from April 1, 2004 to December 31, 2009, which are difficult to identify for individual slow slip events (SSEs). … To investigate the characteristics of the detected crustal deformation, we estimated the parameters of a rectangular fault model in segments along the Nankai Trough using a non-linear inversion method. …

    Earth, Planets and Space (71), 2019-09-06

    IR 

  • Forecasting Climatic Trends Using Neural Networks: An Experimental Study Using Global Historical Data

    Ise Takeshi , Oba Yurika

    ディープラーニングにより精度97%で気温の上下を推定する手法を開発 --疑似カラー画像による効率的な自動識別--. 京都大学プレスリリース. 2019-04-26.

    Frontiers in Robotics and AI (6), 2019-04-26

    IR 

  • Benchmark Analyses of Elastic-Plastic Seismic Response Evaluation of Piping Systems  [in Japanese]

    中村 いずみ , 渡壁 智祥 , 大谷 章仁 , 澁谷 忠広 , 森下 正樹 , 白鳥 正樹

    … Based on the BA_#01 results, the setting of the yield stress has a significant effect on the analytical results, whereas the setting of the second inclination of the bi-linear model and the approximation method of the stress-strain curve are not so significant. …

    防災科学技術研究所研究資料 = Technical Note of the National Research Institute for Earth Science and Disaster Resilience (429), 1-72, 2019-03-28

    IR  DOI 

  • Seismotectonics of the 2018 northern Osaka M6.1 earthquake and its aftershocks: joint movements on strike-slip and reverse faults in inland Japan

    Hallo Miroslav , Opršal Ivo , Asano Kimiyuki , Gallovič František

    … The earthquakes were located near the Arima-Takatsuki Tectonic Line (ENE-WSW dextral strike-slip faults) and the Uemachi fault system (N-S reverse faults), hence the seismotectonic interpretations we assumed to be rather complex. … Here we propose a seismotectonic model of this sequence based on seismological data and stress field considerations. … The activated N-S reverse fault is dipping to east by 50° similarly as the Uemachi fault system. …

    Earth, Planets and Space (71), 2019-03-27

    IR 

  • Coseismic and Postseismic Deformation of the 2016 Central Tottori Earthquake and its Slip Model

    Meneses-Gutierrez Angela , Nishimura Takuya , Hashimoto Manabu

    … We analyze Global Navigation Satellite System (GNSS), Interferometric Synthetic Aperture Radar, and accelerometer data within the San‐in Shear Zone in order to clarify the coseismic and postseismic slip distributions associated with the Mw6.2 2016 Central Tottori earthquake. …

    Journal of Geophysical Research: Solid Earth 124(2), 2202-2217, 2019-02

    IR 

  • An Experimental Study on Collapse Behavior of a Piping System Model under Excessive Input Motion  [in Japanese]

    NAKAMURA Izumi , KASAHARA Naoto

    … In this study, lead-antimony (Pb-Sb) alloy was adopted as the simulation material, and shaking table tests on piping system models were conducted. … The piping system model were composed by two elbows made of Pb-Sb alloy, one additional mass, and steel bars. …

    The Proceedings of the Dynamics & Design Conference 2019(0), 229, 2019

    J-STAGE 

  • Observing system simulation experiment for radio occultation measurements of the Venus atmosphere among small satellites

    SUGIMOTO Norihiko , ABE Mirai , KIKUCHI Yukako , HOSONO Asako , ANDO Hiroki , TAKAGI Masahiro , GARATE LOPEZ Itziar , LEBONNOIS Sebastien , AO Chi

    … <p>We have developed the Venus AFES (atmospheric GCM (general circulation model) for the Earth Simulator) LETKF (local ensemble transform Kalman filter) data assimilation system (VALEDAS) to make full use of observations. … In this study, radio occultation measurements among small satellites are evaluated by the observing system simulation experiment (OSSE) of VALEDAS. …

    Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM)) 75(2), I_477-I_486, 2019

    J-STAGE 

  • In-orbit straylight characterization and correction of optical radiometer using the moon image

    ANDO Shigemasa , TANAKA Kazuhiro

    … The irradiance obtained by the integration of the radiance of moon pixels is compared to the referential irradiance that derives from the astrophysical model, and the comparison result includes the gain characteristics of radiometer. … It is shown that LSF (line spread function) measured in the moon limb is effective trend monitor of radiometer's geometric property in orbit and is also a key to verify the validity of straylight correction model implemented in the ground data processing system. …

    Mechanical Engineering Journal 6(6), 19-00098-19-00098, 2019

    J-STAGE 

  • GSMaP RIKEN Nowcast: Global Precipitation Nowcasting with Data Assimilation

    OTSUKA Shigenori , KOTSUKI Shunji , OHHIGASHI Marimo , MIYOSHI Takemasa

    … <p> Since January 2016, RIKEN has run an extrapolation-based nowcasting system of global precipitation in real time. … Therefore, this paper aims to examine how motion vectors can be derived more accurately, and how data assimilation can stably constrain an advection-diffusion model for extrapolation for the long-term operation. … The Japan Aerospace Exploration Agency's Global Satellite Mapping of Precipitation (GSMaP) near-real-time product is the only input to the nowcasting system. …

    Journal of the Meteorological Society of Japan. Ser. II 97(6), 1099-1117, 2019

    J-STAGE 

  • Cutterhead mud-caking detection method and application based on cutter wear and temperature measurement

    JI Zhiyong , XIA Yimin , LAN Hao , YANG Mei , LIN Laikuang

    … To predict the mud-caking status in real time, a prediction model was established based on cutter temperature characteristics, and a bus-based detection system was designed to monitor cutter wear and temperature in tunneling. … Such prediction model and detection system were verified on an earth pressure balance (EPB) TBM at a Shenzhen metro project. …

    Journal of Advanced Mechanical Design, Systems, and Manufacturing 13(4), JAMDSM0088-JAMDSM0088, 2019

    J-STAGE 

  • Implementation and Demonstration of a System for the Forecasting of Surface Avalanche Potential Caused by Snowfall from a Cyclone

    Nakamura Kazuki

    … Accordingly, a system has been designed and implemented to show, in a two-dimensional model, the surface avalanche potential caused by snowfall from cyclones in a 5 km square mesh across Japan. … A demonstration experiment was conducted to provide the information and verify the system. …

    Journal of Disaster Research 14(9), 1201-1226, 2019

    J-STAGE 

  • Mars and Earth - distinct inner solar system products  [in Japanese]

    Yoshizaki Takashi , F. McDonough William

    <p>地球型惑星の化学組成は,その形成進化過程を理解する上で重要な指標となる。我々は,火星隕石や探査機の物理・化学データを元に,火星の化学組成モデルを新たに構築した。火星や地球は,太陽系内側由来のコンドライト母天体に比べ,より難揮発性の物質から集積したことが明らかになった。火星においても,地球に比べ程度は小さいものの,揮発性が高い中揮発性元素ほど枯渇している傾向が認められ,火星の金属核 …

    Abstracts of Annual Meeting of the Geochemical Society of Japan 66(0), 176, 2019

    J-STAGE 

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