Kessler and McPhaden, 1995b Abstract
The 1991-93 El Niño in the central Pacific
Kessler, W.S. and M.J. McPhaden, 1995
Deep-Sea Research II, 42, 295-333.
The 1991-93 El Niño event is described using data from the TOGA-TAO
buoy network, concentrating on variability at 140W where a full
suite of temperature, current, and surface meteorological observations
were made. The daily time series furnished by the buoy array brings out
the conspicuous importance of remotely forced intraseasonal variability
in the form of equatorial baroclinic Kelvin waves during the evolution
of the 1991-93 El Niño. Notable variations along 140W included
a major weakening of the Equatorial Undercurrent in late 1991-early 1992,
and a reduction in intensity of monthly period tropical instability waves
during the latter part of 1991 compared to previous non-El Niño years.
The North Equatorial Countercurrent showed no major signal due to this
El Niño, in contrast to earlier warm events. Although anomalies of the
South Equatorial Current spanning the equator were in an eastward sense
during the height of the event, the result of these changes was that near-
surface flow across 140W between 5S and 5N was
close to zero, so there was apparently no large eastward transport of
surface water past 140W into the eastern equatorial Pacific. The
relative phasing of anomalies of thermocline depth, equatorial undercurrent
speed and SST during the warm event of 1991-92 was somewhat similar to that
seen during the 1986-87 El Niño, although the earlier event was
followed by a strong cold (La Nina) event whereas the recent one was not. Uniquely among modern El Niño events, after the 1991-92 episode
appeared to end with a reappearance of the equatorial cold tongue in mid-1992,
a second SST warming in the eastern Pacific occurred in early 1993.
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Download the paper as it appeared in Deep-Sea Research (pdf, 2.4 Mb) (a scan that ruins the color figures)
