Tropical
Highlights – January 2012
Mature La
Niña conditions continued during January 2012 as negative sea surface
temperature anomalies persisted across the eastern and central equatorial
Pacific Ocean (Fig. T18, Table T2). The latest monthly Niño indices were -1.1°C for
the Niño 3.4 region and -0.8°C for the Niño 1+2 region (Table T2,
Fig. T5). Consistent
with these conditions, the oceanic thermocline (measured by the
depth of the 20°C isotherm) remained shallower
than average in the east-central equatorial Pacific (Figs. T15, T16), where corresponding
sub-surface temperatures were 1-4°C below average (Fig. T17).
Also during
January, the equatorial low-level easterly trade winds and upper-level westerly
winds were stronger than average over the central and west-central equatorial Pacific
(Table T1,
Figs. T20, T21). Convection
remained suppressed in the western and central equatorial Pacific and enhanced over
Indonesia (Figs. T25,
E3). Collectively, these oceanic
and atmospheric anomalies reflect a continuation of La Niña conditions.
For the
latest status of the ENSO cycle see the ENSO Diagnostic Discussion at:
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/index.html