T. Delcroix et al., SEA-SURFACE SALINITY CHANGES ALONG THE FIJI-JAPAN SHIPPING TRACK DURING THE 1996 LA-NINA AND 1997 EL-NINO PERIOD, Geophysical research letters, 25(16), 1998, pp. 3169-3172
Sea-surface salinity (SSS) changes during the 1996 La Nina and 1997 El
Nino events are analysed along the Fiji-Japan shipping track, based o
n 20 thermosalinograph sections. In the equatorial band, above-average
SSS (35.2 to 35.4 instead of 35) were observed in 1996, consistent wi
th a well-marked south equatorial current, an unusually-strong equator
ial upwelling, and below-average precipitation (P). From January to Au
gust 1997, the SSS decreased sharply from 35.2 to 33.8 (lowest recorde
d monthly value over the last 20 years), compatible with a reversal of
zonal current, the occurrence of equatorial downwelling, and above-av
erage P. From September to November 1997, the SSS remained almost cons
tant (34.2), consistent with the opposite effects of eastward current,
likely bringing low saline water from the Pacific warm pool, and of e
vaporative cooling, vertical mixing and below-average P which all tend
to increase SSS. The potential impacts of the observed SSS changes on
sea level are discussed.