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1 657-8501 1-1 E-mail:[email protected]
2 657-8501 1-1 E-mail:[email protected]
( JCOPE2-ROMSGPV-MSM (
2014 18 19 ) (
3 (
(
Key Words : typhoon, Kuroshio, near-inertial oscillations, inertial resonance, eddy shedding
1.
( ) (
1)
2) SSH
3) )
)
) 1 m/s 4)
(
3
)
)
JCOPE2-ROMS( 2014
18 19) 1 ) 18 Phanfone
935 hPa 4
19 Vongfong900 hPa 5
(
18 19
18 19
)
)
I_457
土木学会論文集B2（海岸工学），Vol. 72, No. 2, I_457─I_462, 2016.
2.
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3 1) 1 (
GPV-MSM(
2 km( COAMPS
ROMS 5)
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ROMS 3JCOPE2 6)
10 kmMSM
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TS Nudging γ = 1/20 day -17, 8
8)
5) (
( (1) (
3.
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21-30
2 5, 30, 100 mEKE
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10/5 10/7 ( ( 100 m EKE( EKE
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EKE (
EKE 5 m, 30 m
100 m) )
0.4 2 (c), (d)
1(
baroclinic energy fluxes BEFNash 9 BEF
)
F = ʹu ʹp dz−h
η
∫ , ʹv ʹp dz−h
η
∫( ) (1)
ʹp z( ) = p0 + g ʹρ z,T,S( )z
η
∫ dz (2)
F BEF h η
u’, v’ p’p0 ρ’
T S z
4 BEF3 (a) 18 10/5
BEF 5(
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10/2 10/18 BEF 3 (b), (c)
-1 ROMS 3 (
2014 18192014 10
I_458
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4.
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( (1)
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5 (e)( 4. (2)
-2 18 2014 10 5 15:00 UTC 18 2 10 7
15:00 UTC a b c d 5 30 100 m18
-3 a baroclinic energy flux F
9/1 10/22 4b 9/1 9/30 c
18 19 10/2 10/18BEF
18 19
I_459
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4 xk < 50 km 3
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(
45 (f)
Q = ρCpuT dA∫ (3)
Q ρ Cp
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-4
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StBearman St
( Reynolds(
f = (St ⋅U) / h (4)
f U h St ≈
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3
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xt
9
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I_461
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B 15H0404926G-0518-5
1) )
B2 , Vol.7, No.2, pp.I_211-I_216 2015. 2) 6804
Vol.10 No.2 pp.137 to 145 2001. 3)
- Vol. 30 pp. 4–15 1992. 4) Church, J. A., T. M . Joyce, and J. F. Price : Current and
density observations across the wake of Hurricane Gay. J. Phys. Oceanogr., Vol. 19, pp. 259-265, 1989.
5) B3
, Vol. 71, No. 2, pp. I_383-I_388, 2015. 6) Miyazawa, Y. and Coauthors: Water mass variability in the
western North Pacific detected in a 15-year eddy resolving ocean reanalysis. J. Oceanogr., Vol. 65, pp. 737-756, 2009.
7) JCOPE2-ROMS����������������������
��� , B2 , Vol. 68, No. 2, pp. I_436-I_440, 2012.
8) Argo 3
(
B3 , Vol. 71, No. 2, pp. I_383-I_388, 2015. 9) Nash, J. D., M. H. Alford, and E. Kunze: Estimating inter-
nal wave energy fluxes in the ocean, J. Atmos. Oceanic Technol., Vol. 22, No. 10, pp. 1551–1570, 2005.
10) Bearman, P.W.: On vortex street wakes, J. Fluid Mech., Vol. 28, pp. 625-641,1967.
(2016. 3. 16 )
IMPACTS ON THE KUROSHIO DUE TO TYPHOONS OFF SHIKOKU ISLAND AND KII CHANNEL
Hiroaki TADA and Yusuke UCHIYAMA
A submesoscale eddy-permitting oceanic reanalysis is carried out with exploiting the JCOPE2-ROMS
downscaling system forced by the JMA GPV-MSM atmospheric reanalysis with a particular attention to the two consecutive super typhoons Phanfone and Vongfong in the fall 2014. On the Pacific side of Japan off Shikoku Island, the Kuroshio main body oscillates horizontally and vertically upon collisions with near-inertial internal gravity waves maintained by inertial resonance in the mixed layer, followed by sub-stantial alteration of the Kuroshio path in the downstream region. A velocity rotary spectrum extracts a distinct peak in the near-inertial frequency band on the offshore side of the Kuroshio with clockwise rota-tion due to near-inertial oscillations caused by the typhoons. On the coastal side, it peaks at around peri-ods of about 3 days with counter-clockwise rotation, which correspond to the shedding frequency of mesoscale eddies released from Cape Ashizuri. These eddies are enhanced by the typhoons to promote oscillations of the Kuroshio axis at around the 3-day period.
8 -4
20149 28 2014 10 22
-9 -4
xt
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