Tropical Pacific Drifting Buoys
Rick Lumpkin / Mayra Pazos, AOML, Miami
During June 2008, 329 satellite-tracked surface drifting buoys, 84% with subsurface drogues
attached for measuring mixed layer currents, were reporting from the tropical Pacific.
A number of drifters in the eastern half of the basin measured very strong eastward anomalies
of 30-40 cm/s between 2S and 5N, an intensification of the pattern seen in April and May.
Weak westward anomalies were more commen farther off the equator, particularly in the western
half of the basin. Cold SST anomalies (-0.5 to -1.5C) were measured by most drifters in the
central Pacific (170E to the 130W) at 5N to 15N, while warm anomalies (+0.5 to +1.5C)
were measured in the southeastern and southern (below 10S) tropical Pacific basin.
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
c) Bottom: Anomalies from the climatological monthly mean currents for this month.