Tropical Pacific Drifting Buoys
Rick Lumpkin / Mayra Pazos, AOML, Miami
During July 2012, 311 satellite-tracked surface drifting buoys, 66% with
subsurface drogues attached for measuring mixed layer currents, were reporting
from the tropical Pacific. Strong eastward anomalies of order 40 cm/s were
observed by a small number of drifters at both ~100W and ~150W, on and north
of the equator. As seen since May, warm anomalies of +0.5 to +3.0C were
measured by many drifters east of 140W in the latitude band 10N-30S, with the
warmest anomalies measured by drifters off the Peruvian coast.
Top:Movements of drifting buoys in the tropical Pacific Ocean during jul12.
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 black.
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.
Bottom: Anomalies from the climatological monthly mean currents for this month.