Low-frequency sea-level variability in the South China Sea and its relationship to ENSO

• Published in: Theoretical and applied climatology Vol. 97; no. 1-2; pp. 41 - 52
• Main Authors: Han, Guoqi, Huang, Weigen
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Vienna Springer Vienna 01.06.2009; Springer; Springer Nature B.V
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Sciences; Climate; Climatology; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; El Nino; Exact sciences and technology; External geophysics; Marine; Ocean temperature; Ocean-atmosphere interaction; Physics of the oceans; Salinity; Satellite altimetry; Sea level; Southern Oscillation; Special Issue; Surface waves, tides and sea level. Seiches; Waste Water Technology; Water Management; Water Pollution Control; South China Sea; Pacific Ocean; West Pacific; Equatorial Pacific; ISEW, South China Sea; Empirical Orthogonal Function Mode; Steric Height; Salinity Climatology; Decadal Variability; time series analysis; Teleconnection; Tide gauge; Space remote sensing; Regional scope; Satellite observation; ocean-atmosphere interaction; Interannual variation; annual variations; El Nino; Southern oscillation; Decadal variation; Radar altimetry; Observation data; sea level
• ISSN: 0177-798X; 1434-4483
• DOI: 10.1007/s00704-008-0070-0

Sea-level variability in the South China Sea was investigated based on satellite altimetry, tide-gauge data, and temperature and salinity climatology. The altimetric sea-level results clearly reveal three distinct amphidromes associated with the annual cycle. The annual sea level is higher in fall/winter in the coast and shelf region and lower in summer/fall in the central sea, agreeing well with independent tide-gauge data. Averaged over the deep basin (bottom depth > 2,000 m), the annual cycle can be approximately accounted for by the steric height relative to 700 db. Significant interannual sea-level change is observed from altimetry and tide-gauge data. The interannual and longer-term sea-level variability in the altimetric data is negatively correlated (significant at the 95% confidence level) with the El Niño - Southern Oscillation (ENSO), attributed in part to the steric height change. The altimetric sea-level rise rate is 1.0 cm/year for the period from 1993 to 2001, which is consistent with the rate derived from coastal tide-gauge data and approximately accountable for by the steric height calculated relative to 700 db. The tide-gauge sea-level (steric height) rise rate of 1.05 (0.9) cm/year from 1993 to 2001 is much larger than that of 0.22 (0.12) cm/year for the period from 1979 to 2001, implying the sensitivity to the length of data as a result of the decadal variability. Potential roles of the ENSO in the interannual and longer-term sea-level variability are discussed in terms of regional manifestations such as the ocean temperature and salinity.