Research Interests（研究テーマ）

1. Coastal and Ocean Health Index (COHI)

• Pressure, Indicators and Resilience of coastal zone and cities
• Integrated coastal zone risk assessment and management

2. Storm surge and storm waves due to typhoons

• For natural hazards and disaster prevention/mitigation due to storm surge and storm waves

3. Wind and solar energy resource assessment by using a regional climate model

• Wind energy resource assessment in Asian regions by using a meteorological model, WRF.
• Future solar energy resource assessment in Asian regions by analysing the IPCC CMIP5 dataset.

4. Wave energy resource assessment by using a regional climate model and a wind-wave model

• Wave energy resource assessment in Asian regons by usng wind wave model, WaveWatch III

5. Tsunami and inundation modeling with adaptive mesh refinement (AMR)

• Adaptive mesh refinement (AMR):
  • Dynamically adapting the accuracy of solution within ceratin sensitive regions, such as high surface gradient, high vorticity, and high turblulent regions, of computational domain during simulation.
  • high accuracy
  • low computational load

6. Time-series analysis with ensemble empirical mode decomposition (EEMD) and its advancements

• empirical mode decomposition (EMD): Breaking down a signal into intrinsic modes in a time domain. It is useful and adaptive way for analyzing natural signals which are mostly non-linear and non-stationary.
• Recent advancements of EMD:
  • Ensemble empirical mode decomposition (EEMD)
  • Complete EEMD with Adaptive Noise (CEEMDAN)
  • Improved CEEMDAN
• Applications:
  • Non-linear trend estimation of sea-level records
  • Relative sea-level trend estimation for Asian regions

7. Integrated water environment management using Regional Environment Simulator (RES) in Asian regions

=> Applications to Jakarta flood and the Citarum River basin

In 2007, the city of Jakarta, Indonesia, faced one of the worst disastrous flooding in its history and had 68 casualties with Rp. 8 trillion (US $879.12 million) in losses. The causes of the 2007 Jakarta flood were a result of intensified heavy rain, deforestation in areas south of the city, waterways clogged with debris and dumped solid waste, land subsidence due to excessive uptaking of groundwater and the sea level rise. Therefore, the objective of this collaborative research is to improve the water environment for the city of Jakarta and the vicinity Citarum River basin through the followings.

8. Typhoon wind fields for storm surge modeling

• Improve the surface wind forcing for storm surge and storm wave modeling
  • Parametric wind model: ex. pressure gradient winds, Rankine vortex, etc.
  • Meteorological model: ex. WRF (+ Bogus scheme, +Dynamic initialization)
• Blending scheme: Parametric wind + Meteorological model

9. Air-sea interaction : Parameterization of the role of surface-wave breaking

• The role of surface-wave breaking in the air-sea interaction in terms of momentum and heat flux transfer processes.
• Development of bulk formula for momentum and heat flux transfer considering the surface-wave breaking phenomena –> for coupled models and/or earth system models

10. Tropical cyclones (in particular, Typhoons in the western North Pacific (WNP))

• Interests in the typhoon processes (the birth, growth, decay, and death), and the favorable atmospheric and oceanic conditions

11. Future changes in typhoon activities in the WNP

• The impacts of climate change on the typhoon activities in the WNP –> Is it possbile to predict a long-term change in the typhoon number, intensity, the landfall typhoons, and consequential coastal disasters in the East Asia region?

12. Upper ocean response to typhoons

• The ocean response in the ocean mixed layer during the passage of typhoons

13. Circulation in Hiroshima Bay and the Seto Inland Sea

• High-resolution non-hydrostatic simulation of the circulation in Hiroshima Bay
• High-resolution simulation of the circulation in the Seto Inland Sea enough to consider a number of narrow straits .