Water budget variation of the South China Sea in relation to ENSO as determined from space altimetric and gravimetric observations / 以測高衛星與重力衛星觀測南海水量的年際變化

碩士 / 國立中央大學 / 地球科學學系 / 104 / The South China Sea (SCS) is a semi-enclosed marginal sea surrounded by continents and islands, thus, water can only exchange through the straits. In this study, we analyze the water budget variations of SCS during 1993-2014, using (i) the AVISO-released surface geostrophic current (SGC) daily data computed by combining the satellite altimeter data in reference to the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) geoid; (ii) the Gravity Recovery and Climate Experiment (GRACE) monthly time-variable gravity signifying the water mass variation; and (iii) daily sea level variation (SLV) from AVISO satellite altimeter data. We find from (i) that SGC water intrusion into SCS through the Luzon Strait, normally stronger in winter and weaker in summer, is correlated at the coefficient of 0.28 with the Multivariate El Niño Southern Oscillation (ENSO) Index (MEI) apparently under the influence of the variation of monsoon and the strength of Kuroshio in response to the ENSO. As the water mass budget will also be reflected in the gravity and SLV, we use the GRACE data (ii) to find the water mass redistributions and the satellite altimeter data (iii) for the SLV in SCS, both showing similar annual variation patterns. We also conduct the Empirical Orthogonal Function (EOF) analysis on the non-seasonal datasets. We find both leading modes showing unison water rise-and-fall behavior in the whole SCS. Their time series have correlation coefficients up to 0.44 and 0.30, respectively, with the MI. This means SCS water budget is under ENSO influence, not only in the intrusion but also reflected in the mass and sea level height. The SCS water budget variation is larger in normal winters and smaller during El Niño years.

Identiferoai:union.ndltd.org:TW/104NCU05134018
Date January 2016
CreatorsWan-Hsin Yang, 楊婉歆
ContributorsBenjamin Fong Chao, 趙丰
Source SetsNational Digital Library of Theses and Dissertations in Taiwan
Languagezh-TW
Detected LanguageEnglish
Type學位論文 ; thesis
Format72

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