Research Topics in Typhoon Research Department

Study of processes of structual change of typhoons made landfall and its occurence of high wind, heavy rains, storm surge and high wave.

In 2004, ten typhoons, which was over the average 2.6, made landfall on Japan. It brought disasters by high wind around the wide area including North Japan in the case of Typhoon No.18, by gust in the case of Typhoon No.22, and by heavy rain and storm surge in the case of Typhoon No.23. Such disasters to Japan by typhoons was caused by upward flow with large amount of moisture over the wide area along the frontgenesis and inflow with cold surge at the lower troposphere and dry air at the mid troposphere when typhoons moved to mid-latitude. In the plan, the purpose of this study is to investigate structual changes of notable typhoons in 2004 and relationship between their processes and occurreance of high wind, heavy rain, and storm surge. This study will lead to the improvement of imformation for such disasters.

  •  Study of translation, intensity, and structual change of immediate and landfall typhoon. 

    The purpose is to clarify the role of atmospheric and oceanic environment to typhoon translation, intensification, and structual change. Effects of sea surface temperature on intensification of typhoons and the processes of structual changes from typhoons and extratropical cyclones are investigated.

     2004 wind velocity and typhoons

    (Figure) Relationship between surface wind and genesis position of typhoons in 2004 typhoon season.

     2004 sea surface temperature and typhoons

    (Figure) Relationship between SST and trackof typhoons in 2004 typhoon season. Numbers show typhoon number in 2004 season. Red numbers shows the typhoons making landfall on Japan.

  •  Study of relationship between occurence of notable phenomena and structual change of typhoons. 

    Analysing features of high wind, heavy rain, and storm surge by approaching and landing typhoons, numerical simulations are carried out. The purpose is to clarify the effect of atmoshere near typhoon and its environment on occurrence of high wind and heavy rain, and storm surge.


    (Figure) (left panel) Time series of eyewall rotations for Typhoon Songda (T0418) on 5 September 2004, derived from the radar reflectivity from Naha DRAW (The Doppler radar for Airport Weather ). The horizontal axis indicates azimuth angle from eye center. Bold lines are associated with Okinawa Island and the terrain contours at 100-m intervals. (upper-right panel) The outline of pentagonal eye at 1400JST. (lower-right panel) The outline of elliptical eye at 1612JST.


    (Figure) Torrential rainfall in Kii peninsula by T0421.(left panel)rainfall distribution observed by AMeDAS.(right panel)rainfall distribution simulated by NHM.

 Typhoon Department