RAMA: Present Status

1
RAMA Present Status

• M-TRITON (1.5S, 90E)
• Surface buoy was detached and floating to the
  west (Jul., 2008)
• and it was collected on Sep., 2008.
• Subsurface part was recovered and replaced to
  the new m-TRITON
• buoy with Argos III data transmission system
  (Mar., 2009)

m-TRITON Buoys
ADCP

• M-TRITON (5S, 95E)
• - Real-time data transmission stopped (Jul.,
  2008)
• Buoy system recovered and replaced to the new
  m-TRITON buoy (Mar., 2009)

2
New buoys deployed
Argos III antena on m-TRITON
m-TRITON buoy
Monitoring camera is installed on m-TRITON buoy
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RAMA JAMSTEC activities
Japan EOS Promotion Program (JEPP) Oct. 2005 -
Sep. 2010Indian Ocean Moored Buoy Network
Initiative for Climate Studies(IOMICS) 
FY2005
FY2006
FY2007
FY2008
FY2009
FY2010
TRITON
2 TRITON buoys
1.5S, 90E 5S, 95E
m-TRITON Development (small size TRITON buoy
system)
JEPP- IOMICS 
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2
2
2
1
MISMO
one month intensive observations at 0,80E
ADCP
Eq., 90E
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New JAMSTEC Buoy
m-TRITON Buoys
ADCP
New m-TRITON 8S, 95E Dec. 2009
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TRITON/m-TRITON at 5S, 95E
Positive T anomaly in the upper-layer, which is
similar to the condition in the previous three
years.
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Observed Zonal Current at 0N, 90E
Strong semiannual and intraseasonal variability
in the surface layer
Semiannual signal is dominant in the sub-surface
layer, with clear upward phase movement.
Sub-surface eastward zonal current Similar
to the EUC in the Pacific?
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Relation to the zonal pressure gradient
Zonal current at 90E (ADCP data) Climatology
Zonal pressure gradient at 90E (Argo data)
90m-170m average
?u ?t
?p ?x
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Set-up of Pressure Gradient by Equatorial Waves