Summary Report Lecturer: Chia-Ping Chiang Date: 2009/Jun/25
Model Validation~ The System Settings • The whole model domain covers entire North Pacific Ocean ranging from 100°E to 80°W and from 30°S to 60°N. A 1/4° horizontal resolution is used east of 150°E, while a finer horizontal resolution of 1/8° is used west of 150°E. The vertical resolution is linear-exponential stretched grid of 26 layers with a thickness of 6 meter in the top layer. Both domains use the same vertical grids. • Model bathymetry: Interpolated from unfiltered ETOPO-5depth data. Supplemented with the Taiwan’s National Center for Ocean Research’s (NCOR)1-minute high accuracy depth archive in the Asian Seas. • The surface wind forcing: Interpolated monthly Hellerman and Rosenstein winds stress. • Surface sources of heat and fresh water: The Levitus94 seasonal climatology is used to initialize the model. • The eddy viscosity (Ah, Av) and diffusivity (Kh, Kv) used in both domains are 20 m2/sec.
Model Validation~ The Governing Equations • Conservation of Mass • Momentum equations (Horizontal) • Hydrostatic equation (Vertical) • Equation of conservation of salt or energy (potential temperature) • Equation of State (EOS):
Model Description~ The TAI Domain • PCM-1 ~ East of Taiwan • PN ~ East China Sea • TK ~ Tokara Strait south of Kyushu • PCM-5 (ASUKA) ~ South of Japan • 34°N & 38°N ~ Southeast and East of Japan
Near PCM1 ~ East of Taiwan Year 37-39, 5-day running mean WOCE: Mean volume transports during 1994/9-1996/5 were estimated to be 23.3 Sv with a standard error of 2.0 Sv. Max in July-August and Min in October. Liu et al’s (1998): Mean transport estimate of 22.6 Sv from repeat CTD/ADCP sections. Johns et al, (2001): 21.5 Sv with an uncertainty of 2.5 Sv.
Near PCM1 ~ East of Taiwan W. E. Johns et al., (2001) Position & Magnitude Depth & Magnitude Mean downstream velocity structure during Sep 1994–May 1995. Temporal Mean during Year 37-39.
Near PN ~ East China Sea Year 37-39, 5-day running mean Oceanographic Division, Nagasaki Marine Observatory, JMA • The long-term mean relative transport from 1973 to 2000 is 25.8 Sv with a mean seasonal maximum of 27 Sv in summer and minimum of 23.9 Sv in autumn.
Near PN ~ East China Sea M. Andres et al. (2008) CPIES+ADCP observation during October 2003 until November 2004 . E. Oka et al. (2003) Temporal Mean during Year 37-39. Quarterly data of CTD and shipboard ADCP from 1987 to 1997.
Near TK ~ Tokara Strait South of Kyushu Year 37-39, 5-day running mean • Observation from spring 1987 to spring 2005 and many estimates of the Kuroshio volume transport through Tokara Strait ranges from 18 Sv to 32 Sv (Bingham and Talley 1991; Yamamoto et al., 1993; Nakano et al., 1994; Yamamoto et al., 1998; Feng et al., 2000; Zhu et al., 2006).
Near TK ~ Tokara Strait South of Kyushu E. Oka et al. (2003) Year 37 Sep. Year 38 Jun. 40 observations during 1987–97: • 35/40 double current cores 25 Stronger northern core (Type 1) 10 Stronger southern core (Type 2) • 5/40 single southern core (Type 3). There is no case of a single northern core. Year 39 Sep.
Volume Transport TK PN PCM-1
Three Typical Path of the Kuroshio Non-large meander near-shore path Non-large meander off-shore path Large meander path M. Kawabe (2005)
Kuroshio Path Non-Large Near-shore Meander Year 37 Sep. Non-Large Meander Transition (Off to Near) Year 38 Jun. Year 39 Sep. Non-Large Off-shore Meander