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COAWST in Kyoto. Nobuhito Mori and Junichi Ninomiya Disaster Prevention Research Institute Kyoto University, Japan Collaborators John C. Warner (USGS) Eric D’Asaro (U Washington) C.T Chen (NCDR, Taiwan) Metrological Research Institute, Japan + Central Weather Bureau, Taiwan.
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COAWST in Kyoto Nobuhito Mori and Junichi Ninomiya Disaster Prevention Research Institute Kyoto University, Japan Collaborators John C. Warner (USGS) Eric D’Asaro (U Washington) C.T Chen (NCDR, Taiwan) Metrological Research Institute, Japan + Central Weather Bureau, Taiwan August 25-28, WHOI
On Going Studies • Typhoon modeling: WRF-ROMS-SWAN • Target • Sensitivity of wave effects via z0air, z0water and TKE • Current status • Typhoon Mellor (2010), Fanapi (2010) plus 4-6 events • Resolution • ROMS: 1-5 km • Wave effects on current: ROMS-SWAN • Target • Directional wave effects for vortex force • Current status • Theory and preliminary test • Resolution • ROMS: about 50-100 m
Momentum roughness length at ASI Drag coefficient Momentum flux Thermal roughness length Surface exchange coefficient Sensible heat Latent heat, etc. Momentum roughness length Charnock: Viscous term Wave term Atmosphere Choppy wind sea Long swell Calm sea ... Ocean By ElodieCHARLES 3 |
Impact of wave coupling: Charnock vs TY Mean(10/6 21:00 - 10/7 3:00)
Friction Velocity, Sensible/Latent heat fluxRear Side 2009/10/6 18:00 – 10/7 00:00 UTC U10 [m/s] U10 [m/s] Z0 by Charnock Taylor-Yelland Oost Drennan u* [m/s] u* [m/s] Oost results have peak value at closer to center of typhoon. The larger friction velocity and heat flux are estimated by with wave model Sensible heat [W/m2] Sensible heat [W/m2] Latent heat [W/m2] Latent heat [W/m2]
Application to climate change study Present 2100 Case study of TC Haiyan SST Case study of Seto-Inland Sea in Japan
Random wave effects on current COAWST only uses Hs and Tm01 from SWAN to ROMS Kumer et al. (2012)
Stokes driftTheory kh=2.0 JONSWAP g=2.0 MitsuyasuN=10 kh=0.50 JONSWAP g=2.0 MitsuyasuN=10
Implementation of random wave effects to COAWST • Unidirectional regular wave stokes drift • Multidirectional irregular wave stokes drift • Methodology • Assuming directional spectra shape and communicate frequency and directional bandwidth by coupler • Communicate directional spectra directly
Inlet Test: Snapshot of ubar and vbar 2D Irregular 1D Regular