Solar Seminar (Zasshikai) Home Page (FY2019)


Solar Seminar (13:30-15:00 Monday, Room 504 5th floor building 4) Access

Next presenters

Date Time Section Speaker File
11-18 13:00-14:00
main
D. Yamasaki upload or download
14:00-14:30
short
K. Otsuji upload or download
11-25 13:00-14:00
D2 interim report
K. Namekata upload or download
12-02 13:00-14:00
main
Y. Kotani upload or download
14:00-14:30
short
K. Nishida upload or download

Please upload your presentation file!!

Date Section Speaker File
10-07
main
Y.W. Huang upload or download
10-07
short
S. Nagata upload or download
10-21
short
S. Ueno upload or download
10-28
main
A. Tei upload or download
11-18
main
D. Yamasaki upload or download

For Speakers
Presentation time for speaker is
main : 40 minutes as a guide, and 20 minutes discussion.
short : 20 minutes as a guide, and 10 minutes discussion.
Contents of talk are
main : about your study
short : review of recent interesting paper and share information of recent study of the Sun.
Language of slide and talks
Master cource students : Language of slide and talk could be Japanese
Doctor cource students and over : Slide must be English, and talking language could be Japanese
(If those who could not understand Japanese attend the seminar, it is preferable that you talk in English)
Title and Abstract
Please send the title and abstract of your presentation by the day before.
Presentation files
Please upload your presentation files by the start of the seminar.
If the presentation file is very big, please zip the file before uploading.
For Audiences
Honoring speakers
Plase clap your hands as a closure of a presentation to express your respection to a speaker.
For everyone
Publication sharing
Please send a copy of the submitted version of any paper on which they are working to the zasshikai mailing list just after submission
  • Useful webpage list for solar observers.
  • See also Ishii-san's Webpage and Webpage of Kwasan and Hida Observatories.

  • main speaker
    Shibata, Ichimoto, Nagata, Ueno, Asai, Ishii, Nishida, Otsuji, Isobe,
    Kawamura, Denis, Kou, Sakaue, Tei, Namekata,
    Kihara, Kotani, Yamasaki, Tanaka, Tomino, Kimura,

    Short speaker
    Shibata, Ichimoto, Nagata, Ueno, Asai, Ishii, Nishida, Otsuji, Isobe,
    Kawamura, Denis, Kou, Sakaue, Tei, Namekata,
    Kihara, Kotani, Yamasaki, Tanaka, Tomino, Kimura,

    Presentations in 2019-2nd semester (13:00-14:30)

    Date Name Title Abstract File
    10-01
    D3 presentation
    H. Hayakawa
    10-07
    main
    Y.W. Huang

    MB
    short
    S. Nagata

    MB
    10-21
    main
    T. Sakaue Disappearance of taller spicules and drastic decrease in wind's mass loss rate in the weak magnetic field Solar spicule and wind are the manifestations of solar magnetic activity. Their kinetic and thermal features are deeply involved with the magnetic field configuration in the solar atmosphere. Alfvén wave is responsible for the energy transportation in the magnetized atmosphere, and its propagation is affected by some non-linear processes which is crucially important to launch the spicule or drive and heat the solar wind.
    To understand the causal relationship between the magnetic field configuration and the resultant features of solar spicule or wind through investigating the non-linear processes of Alfvén wave, we performed the one-dimensional Magneto-Hydrodynamics numerical simulation. In this study, we consider the several magnetic flux tubes with the different field strengths, and investigate the dependence of typical spicule height and solar wind’s mass loss rate on the magnetic field configuration.
    The simulation results show the disappearance of taller spicules than 10 Mm and drastic decrease in solar wind's mass loss rate (down to ~ a few x10^{-15} M_\odot yr^{-1}) in the case of weak magnetic field. We will discuss these phenomena is caused by the highly non-linear Alfvén wave in the chromosphere.
    pdf

    40MB
    short
    S. Ueno Which wavelength of solar UV has the strongest influence on the ionosphere? As one of subjects of the PSTEP project, we are trying to reproduce long-term solar UV variation that has influence on the ionosphere by using full-disk solar chromospheric images. However, we don't know which wavelength of solar UV has the strongest influence on the ionosphere. For this question, different geophysicists give different answers... Therefore, at present, I am investigating actual long-term relationship between one of physical parameter of the ionosphere and solar UV irradiance at various wavelengths. The ionospheric physical parameter that I use is "geomagnetic solar quiet daily variation (Sq)" 1). On the other hand, solar UV irradiance is obtained from several database, such as FISM, DeLand Composite SSI, Ly-alpha Model SSI, and so on 2). I will report present results in this seminar.

    References:
    1) https://ui.adsabs.harvard.edu/abs/2017SSRv..206..299Y/abstract
    2) http://lasp.colorado.edu/lisird/

    MB
    10-28
    main
    A. Tei IRIS Mg II Observations and Non-LTE Modeling of Off-limb Spicules in a Solar Polar Coronal Hole The solar chromosphere is dynamic and full of fine structures. Among them, spicules are long, thin, dynamic features which jet out ubiquitously from the solar surface, and connect the photosphere to the corona. However, the physical mechanism of spicules and their essential roles related to energy and mass transport is unclear.
    We investigated the off-limb spicules observed in the Mg II h and k lines by IRIS in a solar polar coronal hole. We analyzed the large dataset of obtained spectra to extract quantitative information about the line intensities, shifts, and widths. The observed Mg II line profiles are broad and double-peaked at lower altitudes, broad but flat-topped at middle altitudes, and narrow and single-peaked with the largest Doppler shifts at higher altitudes. We use 1D non-LTE (i.e. departures from Local Thermodynamical Equilibrium) vertical slab models in single-slab and multi-slab configurations to interpret the observations and to investigate how a superposition of spicules along the line of sight (LOS) affects the synthetic Mg II line profiles. The used multi-slab models are either static, i. e. without any LOS velocities, or assume randomly assigned LOS velocities of individual slabs, representing the spicule dynamics. We conducted such single-slab and multi-slab modeling for a broad set of model input parameters and showed the dependence of the Mg II line profiles on these parameters. We demonstrated that the observed line widths of the h and k line profiles are strongly affected by the presence of multiple spicules along the LOS. We later showed that the profiles obtained at higher altitudes can be reproduced by single-slab models representing individual spicules. We found that the multi-slab model with a random distribution of the LOS velocities ranging from -25 to 25 km/s can well reproduce the width and the shape of Mg II profiles observed at middle altitudes.

    MB
    short
    A. Asai •Travel Report : Visit the MUSER site (2019-July-21~24)
    •Paper Introduction: Chen, Xingyao, Yan, Yihua; Tan, Baolin; Huang, Jing; Wang, Wei; Chen, Linjie; Zhang, Yin; Tan, Chengming; Liu, Donghao; Masuda, Satoshi, “Quasi-periodic Pulsations before and during a Solar Flare in AR 12242”, 2019, ApJ, 878, id.78
    pdf

    18MB
    11-11
    main
    K. Kihara Solar Flare Prediction with Image Recognition, Classification of Sunspot Complexity A solar flare is an explosive process that releases magnetic energy on the Sun. Solar flares and their accompanied phenomena are crucial problem for space weather, so it is necessary to predict solar flares before their occurrences. Recently, machine learning techniques have been applied to the problem of solar flare prediction. Our group has been studying this using machine learning and image recognition. In order to construct a reliable flare prediction model, we are now carrying out the classification of sunspot complexity. By using the sunspot classification model, it is possible to improve the accuracy of solar flare prediction. In tomorrow's main talk, I will talk about the current status of our work.
    pdf

    11MB
    short
    T.T. Ishii B1.3 flare observed with Sartorius & SMART, on 2019-Nov-05, in NOAA 12750, belongs to Solar Cycle 25. B1.3 flare observed with Sartorius & SMART,
    on 2019-Nov-05, in NOAA 12750,
    belongs to Solar Cycle 25.
    Report at Zasshikai short, T. T. Ishii
    Sartorius at Kwasan, Observer: M. Kamobe
    SMART at Hida, Observer: K. Otsuji
    Sunspot Sketch 2019/11/01 and report, by A. D. Kawamura
    pptx

    9.3MB
    11-18
    main
    D. Yamasaki Polarization Calibration of the Solar Magnetic Activity Research Telescope (SMART)-T4 The Tandem Etalon Magnetograph (TEM) is one of the 4 telescopes of the Solar Magnetic Activity Research Telescope (SMART). TEM is a filter magnetograph, which scans 4 wavelength points around 630.25 nm. TEM aims to obtain vector magnetic fields on the solar photosphere with a spatial resolution of 0.5-1.0 arcsec. A polarimetric sesitivity of 5*10^-4 is achieved for each wavelength point with integrating 675 images in 20 sec (Nagata et al. 2014). In this study, we performed the end-to-end polarization calibration test and evaluated the polarimeter response matrix of TEM in order to suppress any artificial polarization from crosstalk among Stokes vectors under the statistical noise over TEM's field of view(FOV). As a result, we found a significant spatial distribution through TEM's FOV in some components of TEM's response matrix. Then, we investigated a polarizing beam splitter's polarization property and found a circular diattenuation, which may caused by the stress on PBS, with spatial distribution through TEM's FOV. In today's talk, I am going to introduce TEM's polarization observation and the experiments of the calibration.
    pdf

    17MB
    short
    K. Otsuji The Reversal of a Solar Prominence Rotation about Its Ascending Direction during a Failed Eruption I will briefly introduce the following paper: "The Reversal of a Solar Prominence Rotation about Its Ascending Direction during a Failed Eruption" (https://ui.adsabs.harvard.edu/abs/2018ApJ...864L..37S/abstract), in which a failed filament eruption occurred on 2010 December 10, showing counter-clockwise rotation in the eruptive phase, followed by clockwise motion in the falling phase.
    pptx

    40MB
    11-25
    D2 interim report
    K. Namekata

    MB
    12-02
    main
    Y. Kotani

    MB
    short
    K. Nishida

    MB
    12-09
    main
    N.Kimura

    MB
    short
    H. Isobe

    MB
    12-16
    main
    H. Tanaka
    short
    TBD
    12-23
    main
    Y. Tomino

    MB
    short
    TBD
    01-06
    D3 presentation
    C. Denis
    D3 presentation
    Y.W. Huang
    D3 presentation
    T. Sakaue
    D3 presentation
    A. Tei
    D3 presentation
    A.D. Kawamura
    01-20
    M2 presentation
    K. Kihara
    M2 presentation
    Y. Kotani
    M2 presentation
    D. Yamasaki

    Presentations in 2019-1st semester (13:30-15:00)

    Date Name Title Abstract File
    04-08
    Long
    K. Shibata Solar Physics in future 2019
    pdf

    35MB
    04-15
    Long
    K. Ichimoto Solar Projects in 2019
    pdf

    13MB
    04-22
    short
    K. Namekata Stellar activity and rotation of the planet host Kepler-17 from long-term space-borne photometory I'll introduce the following paper "Stellar activity and rotation of the planet host Kepler-17 from long-term space-borne photometory". A. F. Lanza, Y. Netto, A. S. Bonomo, H. Parviainen, A. Valio, S. Aigrain https://arxiv.org/abs/1904.04489
    pptx

    43MB
    main
    A. Asai DKIST
    pdf

    26MB
    05-13
    short
    A.D. Kawamura
    pdf

    2.9MB
    main
    S. Nagata
    pdf

    6MB
    05-20
    short
    C. Denis Mapping the magnetic field of flare coronal loops in the short talk I am going to introduce the following paper: "Mapping the magnetic field of flare coronal loops", by Kuridze et al. 2019. https://iopscience.iop.org/article/10.3847/1538-4357/ab08e9/meta I will also briefly discuss on the possibility to derive some physical parameters (e.g. temperature, electron density) of the post-flare loop observed by SDDI on 2017 Sep. 10. This based on the theoretical correlations found by Heinzel, Gouttebroze, Vial (1994).
    pdf

    9.1MB
    main
    T.T. Ishii Introduction of SMART (mainly SDDI) at Hida Observatory, and Recent Solar Activities Observed with SDDI I would like to talk about introduction of SMART (mainly SDDI) at Hida Obs., and recent solar activities observed with SDDI.
    pptx

    4.5MB
    06-03
    short
    Y.W. Huang
    main
    S. Ueno 40 Years History of Spectroscopic Researches using Domeless Solar Telescope of Hida Observatory (1979 – 2018) In this year, just 40 years passed after the Domeless Solar Telescope (DST) was built at Hida Observatory in 1979. In this talk, I would like to look back on spectroscopic researches that have been performed in the past 40 years with classifying them by each observation object, as follows.

    Photosphere (Quiet Region)
    - Convection
    - Differential Rotation
    - Gravitational Redshift
    - Line Formation
    Chromospheric Small Activities
    - Ellerman Bomb & Jet
    - Grains, Oscillation
    - Spicule
    Prominence & Dark Filament
    - Quiescent Prominence & Filament
    - Active Prominence & Filament
    Flare
    - Kernel (Asymmetry)
    - Micro-flare
    - Surge
    Sunspot & Active Region
    - Evershed Effect
    - Emerging Flux
    pdf

    19MB
    06-10
    short
    K. Kihara Solar farside magnetograms from deep learning analysis of STEREO/EUVI data In my short talk, I will introduce the following paper:
    "Solar farside magnetograms from deep learning analysis of STEREO/EUVI data" Kim, T., Park, E., Lee, H., et al. 2019, Nature Astronomy
    https://www.nature.com/articles/s41550-019-0711-5
    pdf

    4.3MB
    main
    K. Nishida The Direct Relation between the Duration of Magnetic Reconnection and the Evolution of GOES Light Curves in Solar Flares In today's solar seminar, I will talk about following papers:
    "The Direct Relation between the Duration of Magnetic Reconnection and the Evolution of GOES Light Curves in Solar Flares" Jeffrey W. Reep and Shin Toriumi, 2018, ApJ, 851:4

    "Dependence of Durations of Solar Flares on the Size of Inflow Regions", Keisuke Nishida, Naoto Nishizuka, and Shibata Kazunari, in prep
    pdf

    2.3MB
    06-17
    M2 interim report
    K. Kihara 深層学習による画像認識を用いた太陽フレア予報システムの開発
    pdf

    3.1MB
    M2 interim report
    Y. Kotani 太陽光球で起こるアネモネジェットの数値的研究
    pptx

    25MB
    M2 interim report
    D. Yamasaki 飛騨天文台SMART望遠鏡偏光キャリブレーション
    pdf

    3.5MB
    06-24
    short
    T. Sakaue In the tomorrow's seminar, I will shortly introduce the discussion in the following conference:
    1. PIPA 2019 6/3 - 6/7 @ Palma de Mallorca (Spain) (http://solar1.uib.es/pipa2019/)
    2. TRAPPIST-1 Conference 6/11 - 6/14 @ Liege (Belgium) (https://events.uliege.be/trappist-1/)
    pdf

    7.0MB
    main
    K. Otsuji Preparing for DKIST: An Introduction to ground based data In the next solar seminar, I will report the summery of the workshop held at Boulder in three weeks ago.
    Title: "Preparing for DKIST: An Introduction to ground based data".
    pptx

    101MB
    07-01
    short
    Y. Kotani Chromospheric Cannonballs on the Sun In my short talk, I will introduce the following paper.
    "Chromospheric Cannonballs on the Sun"
    Shuhong Yang, Jun Zhang, Xiaohong Li, Zhong Liu, Yongyuan Xiang
    https://arxiv.org/abs/1906.10850
    (ApJL, accepted 2019 June 25)
    pdf

    4.8MB
    main
    H. Isobe IRIS/SDDI observation of an emerging flux region I will be talking about
    “IRIS/SDDI observation of an emerging flux region”
    on which I have been working with Durgesh Tripathi and his student, also with a help from Otsuji-san about the SDDI data.
    pptx

    34MB
    07-08
    short
    A. Tei Spectral Diagnosis of Mg II and Hα Lines during the Initial Stage of an M6.5 Solar Flare In the tomorrow's short talk, I will introduce Huang et al. 2019, ApJL, 878, 15.The title is "Spectral Diagnosis of Mg II and Hα Lines during the Initial Stage of an M6.5 Solar Flare".
    https://ui.adsabs.harvard.edu/abs/2019ApJ...878L..15H/abstract

    MB
    main
    A.D. Kawamura

    MB
    07-22
    short
    D. Yamasaki Very Fast Helicity Injection Leading to Critically Stable State and Large Eruptive Activity in Solar Active Region NOAA 12673 In my tomorrow’s solar seminar short talk, I will introduce “Very Fast Helicity Injection Leading to Critically Stable State and Large Eruptive Activity in Solar Active Region NOAA 12673” (Vemareddy 2019):https://ui.adsabs.harvard.edu/abs/2019ApJ...872..182V/abstract
    pdf

    17MB
    main
    C. Denis Fast-filament eruption detected by SMART/SDDI on 2017 April 23 Tomorrow in main talk of the solar seminar, I will present progress about my analysis of the "fast-filament eruption detected by SMART/SDDI on 2017 April 23".
    In the first part of my presentation I am going to discuss the kinematics, while in the second part I will show a very rough estimation of the kinetic and potential energies of the filament eruption.
    pdf

    8.8MB
    07-29
    No seminar



    Previous presentations

    2018 Zasshikai Website
    Go to Zasshikai 2018
    2017-2nd Zasshikai Website
    Go to Zasshikai 2017-2nd
    2017-1st Zasshikai Website
    Go to Zasshikai 2017-1st
    2016 Zasshikai Website
    Go to Zasshikai 2016
    2015 Zasshikai Website
    Go to Zasshikai 2015
    All of 2014
    2014 Archive (tar.gz file, 1.9Gbyte)
    All of 2013
    2013 Archive (tar.gz file, 2.4Gbyte)
    All of 2012
    2012 Archive (tar.gz file, 780Mbyte)
    All of 2011
    2011 Archive (tar.gz file, 780Mbyte)
    All of 2010
    2010 Archive (tar.gz file, 625Mbyte)



    If there are any mistakes or errors in this webpage,
    please send e-mails to the organizer, Kihara (kihara_at_kwasan.kyoto-u.ac.jp).