Weak La Niņa conditions
continued during March 2009, as negative sea surface temperature (SST) anomalies
persisted the central and east-central equatorial
The latest monthly SST index was -0.5°C in the Niņo-3.4 region,
and -0.3°C in the Niņo-4 region (Table T2).
The oceanic thermocline along
the equator, measured by the depth of the 20°C
isotherm, remained shallower than average in the far eastern Pacific and deeper
than average across the western Pacific during March (Figs. T15,
T16). Consistent with these conditions,
temperatures were 1-5oC below average at thermocline depth in the far
eastern Pacific (Fig. T17).
Convection remained suppressed
over the central equatorial
and enhanced across
during March 2009 (Figs. T25,
T26 and E3).
Collectively, this combination of oceanic and atmospheric conditions reflects a
weakening of La Niņa.
the latest status of the ENSO cycle see the ENSO Diagnostic Discussion at: