Interannual sea surface salinity variations observed in the Tropical North Pacific Ocean
Li, Y.anlong; Wang, Fan; Han, Weiqing
Geophysical Research Letters 40(10): 2194-2199
2013
ISSN/ISBN: 0094-8276
DOI: 10.1002/grl.50429
Accession: 036834076
Analysis of observational datasets reveals pronounced interannual variations of sea surface salinity (SSS) in the tropical North Pacific (TNP; 7 15 N) during 2000 2012. SSS anomalies with maximum magnitudes>?0.2 occur in the central Pacific and translate westward at a speed of 15 20?cm?s-The signals are weakened during their westward movement but reinforced in the Philippine Sea. Budget analysis for the mixed layer salinity suggests that in the central Pacific, ENSO-related atmospheric freshwater forcing and ocean advection changes are both important in generating and maintaining these large SSS anomalies. In the advection term, the most contributing component is the meridional Ekman advection induced by trade winds. These SSS anomalies are subsequently carried westward by the North equatorial Current (NEC), which is the primary cause of SSS variations in the Philippine Sea. Freshwater forcing is also at work in the Philippine Sea, but its role is generally secondary.