East Asia and Western Pacific METEOROLOGY AND CLIMATE

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current between 127° E—128° E became very slow
with the highest speed less than
20 on/sec although some data about the Kuroshio Current near the Philippine
coast was missed, while the southward flow was expanded and more obvious. The
deflection of the current directions (see Fig.6(b)) shows somethihg like an eddy
centered at 127° E. In April 1988, the northward flow (the Kuroshio current)
became stronger again, with a highest speed more than 80 cm/sec near the
Phillippine coast, and a much weaker southward current can be seen to the east of
124.5° E(see Fig. 6(c)). Therefore, the western boundary current at 18.3° N
section appears interannual variabilities related to the El Nino event.
Recently, Toole et.al have utilized the inverse method to work out the
variations of the transportation in a box of 8° N~18° 20'N, west of 130° E
between Cruise 3 and Cruise 4, based on the CTD data. Their result shows an
northward
transportation across the 18° 20*N section was 12.3xl0 9 kg/sec in the
top layer above a e -26.25 in the 3rd cruise and 30.6Xl0 9 kg/sec in the 4th
cruise
t61 *)
. Toole also estimates the annual mean transport of 15.7X10 kg/sec
crossing the section 18° 20*N for water warmer than 12° C potential temperature
(closely corresponding to the top layer in Reference 6) ''. Therefore, the result
estimated from the CTD data also show the interannual variabilities of the
northward transportation on the 18° 20*N section, similar to that proved by the
ADCP measurements.
We will assume, based on the analysis discussed above, that the northward
transportation of the heat energy from the area equatorward of 18° 20 *N and west
of 130° E significantly decreased in the period from the mature stage to about
the end of an El Nino event. The decrease of the heat transportation would result
in less heat content of the upper NWPO north of 18° "20% even further to the
middle latitudes where the kuroshio flows, with a certain time-lag or phase-lag.
Therefore, the upward heat flux from the NWPO to the atmosphere in the
subtropical High might ..be less than the normal conditions, in a period after an
El Nino event had started* It is the reason why the subtropical High over the
NWQ can be getting stronger and larger than normal after El Nino events have
started.
CONCLUSION
The above discussion based on the data related to the subtropical High over