Tropical Pacific Drifting Buoys
Rick Lumpkin / Mayra Pazos, AOML, Miami
FEBRUARY 2009
During February 2009, 362 satellite-tracked surface drifting buoys,
82% with subsurface drogues attached for measuring mixed layer currents,
were reporting from the tropical Pacific. Across the basin, the westward
SEC and NEC were both stronger by 10 cm/s than their climatological February
strengths. Strong eastward anomalies in the eastern NECC may have been
associated with instability waves. East of 140W, SSTs were close to
climatological February values. Between 140W and the dateline, many cold
(-0.5 to -1.5C) anomalies were measured by drifters between 25N and 10S.
West of the dateline, SSTs were close to or slightly warmer (+0.5 to +1.5C)
than climatology.

FIGURE A1.1
a) Top: Movements of drifting buoys in the tropical Pacific Ocean.
The linear segments of each trajectory represent a one week displacement.
Trajectories of buoys which have lost their subsurface drogues are gray; those with
drogues are blue.
b) Middle: Monthly mean currents calculated from all buoys 1993-2002 (gray),
and currents measured by the drogued buoys this month (black) smoothed by an
optimal filter.
c) Bottom: Anomalies from the climatological monthly mean currents for this month.
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