of global tropical sea surface temperature (SST) anomalies during March
featured negative anomalies in the east-central equatorial Pacific, with SST
anomalies of -0.6 in the Niņo 3.4 and Niņo 3 regions (Fig. T18,
Table T2). Meanwhile, the SST anomalies in the
Niņo 1+2 region remained slightly positive (Fig. T18,
Table T2). The
- Darwin SOI (latest value 1.4, Table T1, Fig. T1)
was positive, in response to higher-than-average pressure over
and lower-than-average pressure over
The latter is consistent with enhanced convection over the western tropical
Pacific, including northern
during March (Fig. T25).
thermocline, measured by the depth of the 20°C
isotherm along the equator, featured deeper-than-average depth in the
western-central Pacific and shallower-than-average depth in the eastern
Pacific during March (Figs. T15, T16).
Consistent with these conditions, equatorial oceanic temperatures at
thermocline depth were 1-2oC above average across the
western-central equatorial Pacific and 2-5oC below average across
the eastern equatorial Pacific (Fig. T17).
March, low-level easterly anomalies (more than 3.0 m s-1) were
observed over the central equatorial Pacific, just south of the Equator, and
westerly anomalies were observed over
(Fig. T20). Enhanced convection
(above-average rainfall amounts) was observed over
, while suppressed convection occurred over the central and east-central
equatorial Pacific (Figs. T25,
T26 and E3).
These features are consistent with cold (La Niņa) conditions.