Curriculum Vitaes

Shin-ya MURAKAMI

  (村上 真也)

Profile Information

Affiliation
Associate Senior Researcher, Institute of Space and Astronautical Science, Lunar and Planetary Exploration Data Analysis Group, Japan Aerospace Exploration Agency
Degree
Doctor of Science(Mar, 2011, Kobe University)

Researcher number
40769783
ORCID ID
 https://orcid.org/0000-0002-7137-4849
J-GLOBAL ID
201501011383506237
researchmap Member ID
B000249646

I'm working on archiving data sets acquired by space and planetary exploration missions.


Papers

 40
  • Takeshi Horinouchi, Toru Kouyama, Masataka Imai, Shin‐ya Murakami, Yeon Joo Lee, Atsushi Yamazaki, Manabu Yamada, Shigeto Watanabe, Takeshi Imamura, Javier Peralta, Takehiko Satoh
    Journal of Geophysical Research: Planets, Mar, 2024  
  • Makoto Taguchi, Toru Kouyama, Temma Sugawa, Shin-ya Murakami, Masahiko Futaguchi
    Earth, Planets and Space, Apr 10, 2023  
  • Yukiko Fujisawa, Shin-ya Murakami, Norihiko Sugimoto, Masahiro Takagi, Takeshi Imamura, Takeshi Horinouchi, George L. Hashimoto, Masaki Ishiwatari, Takeshi Enomoto, Takemasa Miyoshi, Hiroki Kashimura, Yoshi-Yuki Hayashi
    Sep 23, 2022  
  • Yukiko Fujisawa, Shin-ya Murakami, Norihiko Sugimoto, Masahiro Takagi, Takeshi Imamura, Takeshi Horinouchi, George L. Hashimoto, Masaki Ishiwatari, Takeshi Enomoto, Takemasa Miyoshi, Hiroki Kashimura, Yoshi-Yuki Hayashi
    Scientific Reports, 12(1), Aug 26, 2022  Peer-reviewed
    Abstract The planetary missions including the Venus Climate Orbiter ‘Akatsuki’ provide new information on various atmospheric phenomena. Nevertheless, it is difficult to elucidate their three-dimensional structures globally and continuously only from observations because satellite observations are considerably limited in time and space. We constructed the first ‘objective analysis’ of Venus’ atmosphere by assimilating cloud-top horizontal winds on the dayside from the equator to mid-latitudes, which is frequently obtained from Akatsuki's Ultraviolet Imager (UVI). The three-dimensional structures of thermal tides, found recently to play a crucial role in maintaining the super rotation, are greatly improved by the data assimilation. This result is confirmed by comparison with Akatsuki's temperature observations. The momentum transport caused by the thermal tides and other disturbances are also modified by the wind assimilation and agrees well with those estimated from the UVI observations. The assimilated dataset is reliable and will be open to the public along with the Akatsuki observations for further investigation of Venus’ atmospheric phenomena.
  • Norihiko Sugimoto, Yukiko Fujisawa, Mimo Shirasaka, Mirai Abe, Shin-ya Murakami, Toru Kouyama, Hiroki Ando, Masahiro Takagi, Masaru Yamamoto
    Atmosphere, 13(2) 182-182, Jan 24, 2022  
    <jats:p>At the cloud top of the Venus atmosphere, equatorial Kelvin waves have been observed and are considered to play an important role in the super-rotation. We were able to reproduce the wave in a general circulation model (GCM) by conducting an observing system simulation experiment (OSSE) with the help of a data assimilation system. The synthetic horizontal winds of the Kelvin wave produced by the linear wave propagating model are assimilated at the cloud top (~70 km) in realistic conditions, assuming they are obtained from cloud tracking of ultra-violet images (UVI) taken by the Venus orbiters. It is demonstrated using Eliassen–Palm (EP) fluxes that the reproduced Kelvin wave transports angular momentum and plays an important role in the magnitude and structure of the super-rotation, causing the acceleration and deceleration of zonal wind of ~0.1 m/s day−1. The conditions required in order to reproduce the Kelvin wave have also been investigated. It is desirable to have 24 hourly dayside satellite observations in an equatorial orbit, such as the Akatsuki Venus climate orbiter. The results of this type of data assimilation study will be useful in the planning of future observation missions to the atmospheres of planets.</jats:p>

Misc.

 18
  • 杉山耕一朗, 村社光誠, 村社光誠, 村上真也, 村上真也
    宇宙航空研究開発機構研究開発報告 JAXA-RR-(Web), (20-010), 2021  
  • 平田成, 平田直之, 野口里奈, 嶌生有理, 杉田精司, 松本晃治, 千秋博紀, 山本幸生, 村上真也, 村上真也, 石原吉明, 津田雄一, 渡邊誠一郎, GASKELL Robert, PALMER Eric
    日本惑星科学会秋季講演会予稿集(Web), 2020, 2020  
  • Imamura, T., Ando, H., Tellmann, S., P{\"a}tzold, M., H{\"a}usler, B., Yamazaki, A., Sato, T.M., Noguchi, K., Futaana, Y., Oschlisniok, J., Limaye, S., Choudhary, R.K., Murata, Y., Takeuchi, H., Hirose, C., Ichikawa, T., Toda, T., Tomiki, A., Abe, T., Yamamoto, Z.-I., Noda, H., Iwata, T., Murakami, S.-Y., Satoh, T., Fukuhara, T., Ogohara, K., Sugiyama, K.-I., Kashimura, H., Ohtsuki, S., Takagi, S., Yamamoto, Y., Hirata, N., Hashimoto, G.L., Yamada, M., Suzuki, M., Ishii, N., Hayashiyama, T., Lee, Y.J., Nakamura, M.
    Earth, Planets and Space, 69(1), Dec 1, 2017  
    © 2017 The Author(s). After the arrival of Akatsuki spacecraft of Japan Aerospace Exploration Agency at Venus in December 2015, the radio occultation experiment, termed RS (Radio Science), obtained 19 vertical profiles of the Venusian atmosphere by April 2017. An onboard ultra-stable oscillator is used to generate stable X-band downlink signals needed for the experiment. The quantities to be retrieved are the atmospheric pressure, the temperature, the sulfuric acid vapor mixing ratio, and the electron density. Temperature profiles were successfully obtained down to ~ 38 km altitude and show distinct atmospheric structures depending on the altitude. The overall structure is close to the previous observations, suggesting a remarkable stability of the thermal structure. Local time-dependent features are seen within and above the clouds, which is located around 48-70 km altitude. The H2SO4vapor density roughly follows the saturation curve at cloud heights, suggesting equilibrium with cloud particles. The ionospheric electron density profiles are also successfully retrieved, showing distinct local time dependence. Akatsuki RS mainly probes the low and middle latitude regions thanks to the near-equatorial orbit in contrast to the previous radio occultation experiments using polar orbiters. Studies based on combined analyses of RS and optical imaging data are ongoing.[Figure not available: see fulltext.]
  • Murakami Shin-ya, Yamamoto Yukio, Hashimoto George L., Yamada Manabu, Yamazaki Atsushi, Sato Takao M., Ogohara Kazunori, Takagi Masahiro, McGouldrick Kevin, Hirata Naru
    Planetary People - The Japanese Society for Planetary Sciences, 26(3) 92-96, 2017  Lead authorCorresponding author
  • 福原哲哉, はしもと じょーじ, 堀之内武, 今村剛, 岩上直幹, 神山徹, 村上真也, 中村正人, 小郷原一智, 佐藤光輝, 佐藤隆雄, 鈴木睦, 田口真, 高木聖子, 上野宗孝, 渡部重十, 山田学
    日本気象学会大会講演予稿集, (110), 2016  
  • 田口真, 神山徹, 今村剛, 堀之内武, 福原哲哉, 二口将彦, はしもと じょーじ, 岩上直幹, 村上真也, 小郷原一智, 佐藤光輝, 佐藤隆雄, 鈴木睦, 高木聖子, 上野宗孝, 渡部重十, 山田学, 山崎敦, 中村正人
    地球電磁気・地球惑星圏学会総会及び講演会(Web), 140th, 2016  
  • 佐藤毅彦, 中村正人, 今村剛, 山崎敦, 鈴木睦, 上野宗孝, 山田学, 福原哲哉, 小郷原一智, 大月祥子, 村上真也, 佐藤隆雄, 渡部重十, 岩上直幹, 田口真, 高橋幸弘, はしもと じょーじ, 堀之内武, 高木征弘, 神山徹
    地球電磁気・地球惑星圏学会総会及び講演会(Web), 140th, 2016  
  • 佐藤毅彦, 中村正人, 今村剛, 山崎敦, 鈴木睦, 上野宗孝, 山田学, 福原哲哉, 小郷原一智, 大月祥子, 村上真也, 佐藤隆雄, 渡部重十, 岩上直幹, 田口真, 高橋幸弘, はしもと じょーじ, 山本幸生, 堀之内武, 高木征弘, 神山徹
    日本惑星科学会秋季講演会予稿集(Web), 2016, 2016  
  • Masato Nakamura, Nobuaki Ishii, Takeshi Imamura, Takehiko Satoh, Takumi Abe, Chikako Hirose, Atsushi Yamazaki, Junichi Nakatsuka, Tsutomu Ichikawa, Tomoaki Toda, Hiroyuki Toyoda, Sumitaka Tachikawa, Yukio Kamata, Makoto Suzuki, Takao M. Sato, Shin Ya Murakami, Yukio Yamamoto, Naomoto Iwagami, Makoto Taguchi, Tesuya Fukuhara, Shigeto Watanabe, Yukihiro Takahashi, Munetaka Ueno, Manabu Yamada, George L. Hashimoto, Naru Hirata, Toru Kouyama, Kazunori Ogohara, Hiroki Ando, Koichiro Sugiyama, Hiroki Kashimura, Shoko Ohtsuki
    Proceedings of the International Astronautical Congress, IAC, Jan 1, 2016  
    Copyright © 2016 by the International Astronautical Federation (IAF). All rights reserved. Japan&#039;s Venus Climate Orbiter Akatsuki was proposed to ISAS (Institute of Space and Astronautical Science) in 2001 as an interplanetary mission. We made 5 cameras with narrow-band filters to image Venus at different wavelengths to track the cloud and minor components distribution at different heights to study the Venusian atmospheric dynamics in 3 dimension. It was launched on May 21st, 2010 and reached Venus on December 7th, 2010. With the thrust by the orbital maneuver engine, Akatsuki tried to go into the westward equatorial orbit around Venus with the 30 hours&#039; orbital period, however it failed by the malfunction of the propulsion system. Later the spacecraft has been orbiting the sun for 5 years. On December 7th, 2015 Akatsuki met Venus again after the orbit control and Akatsuki was put into the westward equatorial orbit whose apoapsis is about 0.44 million km and orbital period of 14 days. Its main target is to shed light on the mechanism of the fast atmospheric circulation of Venus. The systematic imaging sequence by Akatsuki is advantageous for detecting meteorological phenomena with various temporal and spatial scales. We have five photometric sensors as mission instruments for imaging, which are 1 m-infrared camera (IR1), 2 m-infrared camera (IR2), ultra-violet imager (UVI), long-wave infrared camera (LIR), and lightning and airglow camera (LAC). These photometers except LIR have changeable filters in the optics to image in certain wavelengths. Akatsuki&#039;s long elliptical orbit around Venus is suitable for obtaining cloud-tracked wind vectors over a wide area continuously from high altitudes. With the observation, the characterizations of the meridional circulation, mid-latitude jets, and various wave activities are anticipated. The technical issues of Venus orbit insertion in 2015 and the scientific new results will be given in this paper.
  • 岩山 隆寛, 村上 真也, 渡邊 威
    数理解析研究所講究録, (1944) 1-14, Apr, 2015  
  • 岩山 隆寛, 村上 真也, 渡邊 威
    数理解析研究所講究録, 1944 1-14, Apr, 2015  
  • 岩山 隆寛, 村上 真也, 渡邊 威
    大会講演予講集, 106 420-420, Sep 30, 2014  
  • 村上 真也, 水島 二郎
    数理解析研究所講究録, 1800 184-194, Jul, 2012  
  • Shin-ya Murakami
    Theoretical and Applied Mechanics Japan, 59 206-206, 2011  
    tudy on dynamics of single vortex would be helpful for farther understanding of two-dimensional turbulence, since two-dimensional turbulence can be considered as collective motion of vortices.Melander, et al.(1987) studied an axisymmetrization process of an elliptic vortex with non-uniform vorticity distribution.They discussed qualitatively the effect of the filamentson the axisymmetrization process of the elliptic vortex.However, quantitative studies on such effect have not been performed yet.Thus, we investigate the effect of the filaments on the axisymmetrization of the elliptic vortex through numerical simulations.We find that the filaments play a significant role on the axisymmetrizationof the elliptic vortex only at the early stage of evolution.In contrast, the velocity induced by the vortex core contributes to both the axisymmetrization and the anti-axisymmetrization.
  • 村上 真也, 岩山 陵寛
    大会講演予講集, 98 313-313, Sep 30, 2010  
  • Murakami Shin-ya, Iwayama Takahiro
    Proceedings, ... meeting of Japan Society of Fluid Mechanics, 2010 139-139, Sep 9, 2010  
    We examine the role of the filaments on the axisymmetrization of an isolated elliptic vortex with non-uniform vorticity distribution for a two-dimensional incompressible barotropic fluid, numerically. In order to perform quantitative examination of the role of filaments on the axisymmetrization, firstly, we divide the vorticity field into the elliptic region and the hyperbolic region. The former corresponds to the core of the vortex and the latter the filaments and a weak vorticity region just outside the vortex core. Secondly, we analyse the radial displacement of the maximum and minimum curvature points on a vorticity contour advected by velocities induced by the vorticity of those regions. These investigations result that the vorticity of the hyperbolic region largely contributes to the axisymmetrization at the both points, especially at the time when the filaments are forming.
  • Murakami Shin-ya, Iwayama Takahiro
    Proceedings, ... meeting of Japan Society of Fluid Mechanics, 2009 140-140, Sep 2, 2009  
    Evolution of an isolated 2-D elliptic vortex with non-uniform vorticity distribution is investigated from the viewpoint of the palinstrophy generation. As pointed out in a previous study, the palinstrophy generation rate has a quadrapole structure over the core of the vortex. The palinstrophy generation rate depends on the positive eigenvalue of the rate of strain tensor, the palinstrophy and the alignment angle between the vorticity gradient vector and the eigenvector of the rate of strain tensor associated with the negative eigenvalue. We show that the quadrapole structure over the vortex core, which is pointed out in a previous study, is caused by the alignment angle. We also show that the magnitude of the palinstrophy generation rate is mainly determined by the palinstrophy.
  • 村上 真也, 岩山 隆寛
    大会講演予講集, 89 266-266, Apr 30, 2006  

Presentations

 39

Research Projects

 3