and oceanic conditions during March 2008 reflected a moderate La Niña.
Equatorial sea surface temperatures (SSTs) in the
remained below average from west of the Date Line eastward to 120°W. However,
these departures weakened during the month (Fig.
and the latest Niño-3.4 and Niño-4 index values were only
slightly cooler than -1°C (Table
T2). Meanwhile, the SST anomalies near the west
have been positive since February 2008 (Table
T2, Figs. T9,
oceanic thermocline remained shallower than normal east of 140°W and continued
to deepen in the region west of the Date Line (Fig. T16). Consistent with this
structure, sub-surface temperature at thermocline depth remained below average
(-1°C to -4°C) across the eastern equatorial Pacific, and above average west
of 170°W (Fig. T17).
low-level easterly anomalies persisted across the western and central equatorial
Pacific during the month (Fig. T20,
which is consistent with the shallower-than-average thermocline in the central
and eastern equatorial Pacific (Figs. T15,
T16). These conditions were associated with
enhanced convection (above-average rainfall amounts) across the
and the far western
tropical Pacific, and a continuation of suppressed convection (below-average
rainfall amounts) across the central equatorial Pacific (Figs.
Consistent with these anomalies, the
– Darwin SOI remained
positive (+1.1) (Table T1,
Fig. T1), and the equatorial SOI was +2.4 (Fig.
the latest status of the ENSO cycle see the ENSO Diagnostic Discussion at: