T. Delcroix et al., PRECIPITATION AND SEA-SURFACE SALINITY IN THE TROPICAL PACIFIC-OCEAN, Deep-sea research. Part 1. Oceanographic research papers, 43(7), 1996, pp. 1123-1141
Monthly sea-surface salinity (SSS) and precipitation (P) in the tropic
al Pacific region are examined for the 1974-1989 period. The SSS data
are derived mainly from water sample measurements obtained from a ship
-of-opportunity program, and the rainfall data are derived from satell
ite observations of outgoing longwave radiation. The mean and standard
deviation patterns of SSS and P exhibit good correspondence in the he
avy-rainfall regions characterising the Intertropical Convergence Zone
-(ITCZ), the South Pacific Convergence Zone (SPCZ) and part of the wes
tern Pacific warm pool. An Empirical Orthogonal Function (EOF) analysi
s indicates two dominant modes of variation linking P and SSS changes,
one mode at the seasonal timescale in both convergence zones, and the
other at the ENSO timescale in the central-western equatorial Pacific
(165 degrees E-160 degrees W) and in the SPCZ. The inferences derived
from the EOF analysis are used in a simple linear regression model in
order to try to specify P changes from known SSS changes. A compariso
n between hindcast and observed P changes suggests that, at seasonal a
nd ENSO timescales, SSS changes could be used to infer the timing, but
not the magnitude, of P in the central-western equatorial Pacific (16
5 degrees E-160 degrees W) and in the SPCZ mean area. The effects of e
vaporation, salt advection and mixed-layer depth on the results are di
scussed. Copyright (C) 1996 Elsevier Science Ltd.