Deep near-inertial waves Samoan Passage
Kelly PearsonMatthew Alford James Girton Glenn Carter Gunnar Voet
44'
40'
36'
32'
54' 50' 46'0 5 10
km
Western SillNorthern three (red): T9, T10, T11
(3590-4768/4804/4768 m)
Southern (red): T12 (3390-4976m)
Sill (orange): M5 (3700-4700)
T9 T10 T11
T12
M5
02/07 02/08 02/09 02/10 02/11 02/12 02/13Date (2014)
3600
3800
4000
4200
4400
4600
Dep
th (m
)
0.5 1 1.5Ave. Temp
-0.2 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 0.2
Meridional Shear (T9)40 m vertical average
0.7, 0.8, 0.9, 1, 1.1, and 1.2 isotherms
100 101
Frequency (cpd)
10-3
10-2
10-1
100
101
102
103
Rot
ary
Spec
tra ((
cm/s
)2 /cph
)Rotary Spectra - 4100 m
record length = 6.8432(days)Sample Rate = 17.3895(samples/day)
WidthRate = 0.2Window:10% Cosine Taper50% overlap (every other pt. is indep.)Detide: No
CKE = Cyclonic kinetic energyACKE = Anti-cyclonic kinetic energy
T9 - ACKET10 - ACKET11 - ACKET12 - ACKET9 - CKET10 - CKET11 - CKET12 - CKE
10-2
10-1
100
101
102
103
104
105
106
107
M2f
Meridional Shear * 100 - Zoomed4000
4050
4100
4150
T9
4000
4050
4100
4150
T10
4000
4050
4100
4150
T11
02/07 02/08 02/09 02/10 02/11 02/12 02/13 02/14
4000
4050
4100
4150
T12
-0.2
-0.15
-0.1
-0.05
0
0.05
0.1
0.15
0.2
Strain - Zoomed4000
4050
4100
4150
T9
4000
4050
4100
4150
T10
4000
4050
4100
4150
T11
00:00 06:00 12:00 18:00 00:00 06:00 12:00 18:00 00:00 06:00 12:00 18:00 00:00 06:00 12:00 18:00 00:00 06:00 12:00 18:00 00:00 06:00 12:00 18:00
4000
4050
4100
4150
T12
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Richardson Number
02/09 02/10 02/11 02/12 02/13 02/14
4000
4050
4100
4150
T9
02/09 02/10 02/11 02/12 02/13 02/14
4000
4050
4100
4150
T10
02/09 02/10 02/11 02/12 02/13 02/14
4000
4050
4100
4150
T11
02/09 02/10 02/11 02/12 02/13 02/14
4000
4050
4100
4150
T12
0
1
2
3
4
5
6
7
8
9
10
44'
40'
36'
32'
54' 50' 46'0 5 10
km
Western SillNorthern three (red): T9, T10, T11
(3590-4768/4804/4768 m)
Southern (red): T12 (3390-4976m)
Sill (orange): M5 (3700-4700)
T9 T10 T11
T12
M5
Normalized KE
T12
T9 T10 T11
M5
Conclusions:
• Near-inertial waves observed in the deep thermocline of the Samoan Passage
• Richardson number varies on similar timescales as near-inertial waves
• Near-inertial events are episodic with no observed seasonal pattern
Top Related