Tropical
Highlights � February 2014
�During February 2014, sea surface temperatures (SSTs) were below-average across the eastern equatorial Pacific (Fig. T18, Table
T2). The latest monthly
Ni�o indices were -0.6�C for the Ni�o 3.4 region
and -0.8�C
for the Ni�o 1+2 region (Table T2,
Fig. T5). Consistent
with these conditions, the depth of the oceanic thermocline (measured
by the depth of the 20�C isotherm) remained slightly
below-average across the eastern equatorial Pacific (Figs. T15, T16).
Also
during February, the low-level easterly trade winds remained near-average across
the central and eastern equatorial Pacific and below-average over the western
Pacific (Table T1,
Fig. T20). Meanwhile, tropical convection remained
enhanced over western Pacific and suppressed over the central equatorial
Pacific and western Indonesia (Figs. T25, E3).
Collectively, these oceanic and atmospheric anomalies reflect a continuation of
ENSO-neutral conditions.
Since
August 2013, the equatorial Pacific Ocean has featured considerable
intra-seasonal variability in response to a series of equatorial oceanic Kelvin
waves. Upwelling Kelvin waves produce a cooling of the surface and sub-surface
temperatures, while downwelling Kelvin waves produce
a warming. During early February, an upwelling Kelvin wave had reached the west
coast of South America, producing cooling in that region. By late February, a downwelling Kelvin wave had emerged and reached the central
equatorial Pacific, resulting in a significant sub-surface warming in that
region (Fig. T17).
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