North Equatorial Current (NEC) bifurcation

報告人：沈茂霖　　　　 (Mao-Lin Shen)

112/04/21

Seminar report

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 2

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 3

OFES and observation

Fig. EOF-1 and PC-1 of zonal (142-180oE) and monthly SSHa (Taguchi et al., 2007).

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 4

OFES results

Fig. EOF-2 and PC-2 of zonal (142-180oE) and monthly SSHa (Taguchi et al., 2007).

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 5

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 6

Fig. KOE mode and NPGO signal (Ceballos et al., 2009).

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 7

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 8

ADT and Geostrophic currents

Fig. The EOF-1 (var 59.9%) of the Absolute Dynamic Topography (ADT) and geostrophic currents estimated from the SSHa observation. Unit in colorbar is cm.

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 9

Temporal comparison

(a)

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010-3

-2

-1

0

1

2

3

Nino 3.4WP index-PC1Qiu & Chen (2010)

Fig. Comparison of the long term harmonics of the negative PC of the 1st EOF mode of the ADT and geostrophic current..

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 10

Modeled SSH

Fig. Modeled SSH (left panel) and climatology SSH (the MDT by Rio et al., 2009).

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 11

Seasonal effects

(a) (b)

Fig. The NEC bifurcated latitude and the background SSH distribution for (a) summer and (b) winter.

Strong Kuroshio Current

Strong Mindanao Current

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 12

Numerical experiments

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17Latitude

(o )

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

RBLS sill depth = 500 mNo LS

Fig. The temporal variation of the NEC bifurcated latitude of different numerical experiments.

112/04/21 Mao-Lin Shen, Dept. of Atmospheric Sciences, NTUMao-Lin Shen, Dept. of Atmospheric Sciences, NTU Page 13

Thank you for your attention.