Kyushu University Academic Staff Educational and Research Activities Database
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Toshihiko Hirooka Last modified date:2016.09.21

Professor / Earth Planetary Fluid and Space Sciences
Department of Earth and Planetary Sciences
Faculty of Sciences


Graduate School
Undergraduate School
Other Organization
Administration Post
Other


E-Mail
Academic Degree
Doctor of Science
Field of Specialization
Middle Atmosphere Sciences
Outline Activities
Recently following issues have been studied by the use of satellite data, simulation data based on general circulation models and numerical prediction data based on operational models of the Japan Meteorological Agency:
(1)Stratosphere-troposphere coupling
1. Predictability of sudden stratospheric warmings
2. Relationship between sudden stratospheric warmings and tropospheric circulations
3. Relationship between North Atlantic subtropical jet variations and stratospheric circulations
4. Analyses of the sudden stratospheric warming in the Southern Hemisphere during September 2002 and its predictability
5. Eastward traveling waves of zonal wavenumber 2 in the Southern Hemisphere stratosphere
(2) Relation of the stratospheric circulation to the MLT region
1. Circulation hanges in the MLT region during sudden stratospheric warming events
2. Interaction between stratospheric-tropospheric and mesospheric circulations
(3) Long-term changes of the stratospheric circulation
1. Relationship between interannual changes of stratospheric ozone and the general circulation
2. Quasi-stationary waves of the Southern Hemisphere and the ozone croissant
(4) Large-scale waves in the middle atmosphere
1. Analyses of thermal tides in the stratosphere and the comparison to general circulation model simulation
2. Rossby normal modes in the ozone field
3. Appearance characters of various modes

Japan Meteorological Society Award in 1991
Research
Research Interests
  • Predictability of stratospheric sudden warmings
    keyword : Stratospheric sudden warmings, Predictability, Ensemble forecast
    2003.04Predictability of stratospheric sudden warmings.
  • Circulation hanges in the MLT region during stratospheric sudden warming events

    keyword : Stratospheric sudden warming, Stratosphere, Upper mesosphere, Lower thermosphere
    2010.04Atmospheric tides in the upper stratosphere and lower mesosphere.
  • Long-term changes of stratospheric circulations
    keyword : Stratospheric circulations, Ozone hole, Planetary waves
    1993.04Long-term changes of the stratospheric circulation.
  • Stratosphere-troposphere dynamical coupling
    keyword : Stratospheric circulation, Tropospheric circulation, Stratospheric sudden warming
    2000.04Stratosphere-troposphere coupling.
  • Atmospheric tides in the upper stratosphere and lower mesosphere
    keyword : Atmospheric tides, Diurnal tides, Upper stratosphere, Lower mesosphere
    2003.04Atmospheric tides in the upper stratosphere and lower mesosphere.
Current and Past Project
  • Investigation of formation mechanisms of mesospheric-lower thermospheric circulations and related minor constituent changes by the use of various numerical models models along with observational data
  • Collaboration study on the disaster in Izu Oshima Iland on 16 October 2013 due to the typhoon 26.
  • Investigation of interaction mechanisms between stratospheric sudden warming events and the tropospheric circulation by the use of various numerical models models along with reanalysis data
  • Investigation of circulation changes of MLT region during stratospheric sudden warming events by the use of various numerical models models along with reanalysis data
  • In this research, we aim to understand the dynamical linkage among these internal and external variations of the S-T coupled system comprehensively, and to contribute for improving our ability of prediction of extreme weather events.
  • Investigation of interaction mechanisms between stratospheric sudden warming events and the tropospheric circulation by the use of various numerical models models along with reanalysis data
  • Investigation of effects of stratospheric ozone changes on the general circulation and climate by the use of coupled chemistry-climate models (CCMs) with sophisticated stratospheric chemistry
  • Stratospheric processes and thier dynamical roles in climate changes
  • Modeling and quantitation for solar influences on the atmosphere
  • Comprihensive studies of formation mechanisms and variations of tropospheric circulations by the use of recent global re-analysis data
  • Characteristics of atmospheric gravity wave activity in the polar regions revealed by GPS radio occultation data with CHAMP
Academic Activities
Reports
1. Middle Atmosphere.
2. Do medium-range forecasts become possible by the use of changes in the stratosphere?.
Papers
1. Tomoko Ichimaru, Shunsuke Noguchi, Toshihiko Hirooka, Hitoshi Mukougawa, Predictability changes of stratospheric circulations in Northern Hemisphere winter., Journal of the Meteorological Society of Japan, 94, 1, 2016.02, [URL].
2. Shunsuke Noguchi, Hitoshi Mukougawa, Toshihiko Hirooka, Masakazu Taguchi, Shigeo Yoden, Month-to-month predictability variations of the winter-time stratospheric polar vortex in an operational one-month
ensemble prediction system., Journal of the Meteorological Society of Japan, 92, 6, 2014.08.
3. Chihiro Iida, Toshihiko Hirooka, Nawo Eguchi, Circulation changes in the stratosphere and mesosphere during the stratospheric sudden warming event in January 2009., Journal of Geophysical Research, 119, 2014.04.
4. Y. Yamazaki, K. Yumoto, D. McNamara, T. Hirooka, T. Uozumi, K. Kitamura, S. Abe and A. Ikeda, Ionospheric current system during sudden stratospheric warming events., Journal of Geophysical Research, 117, 2012.03.
5. Y. Harada, A. Goto, H. Hasegawa, N. Fujikawa, H. Naoe and T. Hirooka, A major stratospheric sudden warming event in January 2009., Journal of the Atmospheric Sciences, 67, 2010.06.
6. H. Mukougawa, T. Hirooka and Y. Kuroda, Influence of stratospheric circulation on the predictability of the tropospheric Northern Annular Mode., Geophysical Research Letters, 36, 2009.04.
7. H. Hei, T. Tsuda and T. Hirooka, Characteristics of atmospheric gravity wave activity in the polar regions revealed by GPS radio occultation data with CHAMP., Journal of Geophysical Research, 113, D04107, doi:10.1029/2007JD008938, 2008.02.
8. T. Hirooka, T. Ichimaru, and H. Mukougawa, Predictability of stratospheric sudden warmings as inferred from ensemble forcast data: Intercomparison of 2001/02 and 2003/04 winters., Journal of the Meteorological Society of Japan, 85(6), 919-925, 2007.12.
9. H. Mukougawa, T. Hirooka, Y. Kuroda and T. Ichimaru, Hindcast AGCM experiments on the predictability of stratospheric sudden warming., Nonlinear Dynamics in Geosciences, Springer-Verlag, 221-233, 2007.06.
10. K. Iwao and T. Hirooka, Dynamical quantifications of ozone minihole formation in both hemispheres., Journal of Geophysical Research, 108, doi:10.1029/2005JD006333, 2006.01.
11. H. Mukougawa, H. Sakai and T. Hirooka, High sensitivity to the initial condition for the prediction of stratospheric sudden warming., Geophysical Research Letter, 32, 17, 32, doi:10.1029/2005GL022909, 2005.09.
12. H. Mukougawa and T. Hirooka, Predictability of stratospheric sudden warming: A case study of for 1998/99 winter., Monthly Weather Review, 132, 7, 132(7), 1764-1776, 2004.07.
13. Y. Miyoshi and T. Hirooka, Quasi-biennial variation of the 5-day wave in the stratosphere., Journal of Geophysical Research, 108, D19, 108(D19), doi:10.1029/2002JD003145, 2003.10.
14. Uniqueness of the stratospheric circulation in the Southern Hemisphere during 2002 winter and occurrence of the sudden warming.
Presentations
1. Toshihiko Hirooka, Tsuyoshi Ohata, Nawo Eguchi, Modulation of the semiannual oscillation induced by sudden stratospheric warming events, International Symposium on the Whole Atmosphere (ISWA), 2016.09.14, [URL].
2. Interannual changes of stratospheric ozone as revealed by satellite observations and their relation with dynamical fields (III).
3. Taro Handa, Guangyu Liu, Toshihiko Hirooka, Nawo Eguchi, Interannual changes of stratospheric ozone and their relationship to dynamical processes, SPARC Workshop SHARP2016, 2016.02.18, [URL].
4. Occurrence of stratospheric sudden warmings and its predictability during the Northern Hemisphere winter.
5. Toshihiko Hirooka, Tsuyoshi Ohata, Nawo Eguchi, Modulation of the semiannual oscillation associated with stratospheric sudden warming events, 15th European Meteorological Society Annual Meeting, 2015.09.07, [URL].
6. Taro Handa, Guangyu Liu, Toshihiko Hirooka, Nawo Eguchi, Interannual changes of stratospheric ozone as revealed by satellite observations and their relation with dynamical fields, AOGS 13th Annual Meeting, 2015.08.06, [URL].
7. Relationship between the equatorial semiannual oscillation and stratospheric sudden warming events.
8. Toshihiko Hirooka, Tsuyoshi Ohata, Nawo Eguchi, Equatorial circulation changes up to the mesosopause during stratospheric sudden warming events, 2014 AGU Fall Meeting, 2014.12.17, [URL].
9. Interannual changes of the equatorial semiannual oscillation and their longitudinal dependence.
10. Tropical semiannual oscillations as revealed by Aura EOS/MLS observations.
11. Toshihiko Hirooka, Tsuyoshi Ohata, Koki Iwao, Nawo Eguchi, Equatorial circulation changes in the mesosphere and lower thermosphere during stratospheric sudden warming events, 14th European Meteorological Society Annual Meeting, 2014.10.10, [URL].
12. Interannual changes of the semiannual oscillation induced by stratospheric sudden warming events.
13. Interannual changes of the semiannual oscillation induced by stratospheric sudden warming events.
14. Toshihiko Hirooka, Tsuyoshi Ohata, Chihiro Iida, Nawo Eguchi, Observed circulation changes associated with sudden warming events up to the mesopause level, SPARC General Assembly 2014, 2014.01.16, [URL].
15. Toshihiko Hirooka, Tsuyoshi Ohata, Chihiro Iida, Nawo Eguchi, Observed circulation changes up to the mesopause during sudden warming events, 2013 AGU Fall Meeting, 2013.12.11, [URL].
16. Toshihiko Hirooka, Chihiro Iida, Nawo Eguchi, Circulation changes in the mesosphere during sudden warming events, 11th Scientific Assembly of IAGA, 2013.08.26, [URL].
17. Toshihiko Hirooka, Tsuyoshi Ohata, Hiroaki Naoe, Hitoshi Mukougawa, Origin and behavior of wavenumber 2 during vortex-splitting stratospheric sudden warming events in the Northern and Southern Hemispheres, Davos Atmosphere and Cryosphere Assembly DACA-13, 2013.07.09, [URL].
18. Toshihiko Hirooka, Chihiro Iida, Nawo Eguchi, General circulation changes up to the mesopause during stratospheric sudden warming events, DynVar Workshop 3 and First SNAP Workshop, 2013.04.24, [URL].
19. Chihiro Iida, Nawo Eguchi, Toshihiko Hirooka, General circulation changes up to the mesopause region during stratospheric sudden warming events, WCRP Special Workshop on Ozone Depletion in the Southern Hemisphere, 2013.02.28, [URL].
20. General circulation changes of in the mesosphere during stratospheric sudden warming events.
21. General circulation changes of in the mesosphere during stratospheric sudden warming events.
22. General circulation changes of in the mesosphere during stratospheric sudden warming events.
23. General circulation changes up to the mesopause region during stratospheric sudden warming events..
24. A major stratospheric sudden warming of 2009 and dynamical linkage with troposphere..
25. Atmospheric dynamical coupling through activity changes of gravity waves during stratospheric sudden warming events..
26. Stratosphere-troposphere dynamical coupling during vortex-splitting major stratospheric sudden warming events in the Northern and Southern Hemispheres..
27. Stratosphere-troposphere dynamical coupling through blocking phenomena during recent major stratospheric sudden warmings..
28. A comparison of stratosphere-troposphere dynamical coupling during vortex-splitting major stratospheric sudden warmings in the Northern and Southern Hemispheres. .
29. Atmospheric coupling through wave activity changes associated with recent stratospheric sudden warming events..
30. Solar influence on tidal wave appearance in the middle atmosphere as inferred from CCM simulations..
31. Predictability of stratospheric sudden warmings as inferred from ensemble forecast data..
32. Solar influence on tidal wave appearance in the middle atmosphere..
33. Predictability of stratospheric sudden warmings in the Northern Hemisphere as inferred from ensemble forecast data..
Membership in Academic Society
  • Meteorological Society of Japan
  • American Meteorological Society
  • COSPAR(Committe on Space Research)
  • Japan Geoscience Union
  • American Geophysical Union
Educational
Other Educational Activities
  • 2014.04, In an education program of the Graduate School of Sciences of Kyushu University, I have been engaged in a responsibility of the education program and a pgogram manager of the Advanced Scientist Development Program since October 2007. .
  • 2013.04, In an education program of the Graduate School of Sciences of Kyushu University, I have been engaged in a responsibility of the education program and a pgogram manager of the Advanced Scientist Development Program since October 2007. .
  • 2012.04, In an education program of the Graduate School of Sciences of Kyushu University, I have been engaged in a responsibility of the education program and a pgogram manager of the Advanced Scientist Development Program since October 2007. .
  • 2011.04, In an education program of the Graduate School of Sciences of Kyushu University, I have been engaged in a responsibility of the education program and a pgogram manager of the Advanced Scientist Development Program since October 2007. .
  • 2010.04, In a new education program introduced by The Graduate School of Sciences of Kyushu University, I have been engaged in a program manager of the Advanced Scientist Development Program since October 2007. .
  • 2009.04, In a new education program introduced by The Graduate School of Sciences of Kyushu University, I have been engaged in a program manager of the Advanced Scientist Development Program since October 2007. .
  • 2008.04, In a new education program introduced by The Graduate School of Sciences of Kyushu University, I have been engaged in a program manager of the Advanced Scientist Development Program since October 2007. .
  • 2007.10, In a new education program introduced by The Graduate School of Sciences of Kyushu University, I have been engaged in a program manager of the Advanced Scientist Development Program since October 2007. .