동해에서의 최근 해수면 상승 패턴 및 이들 현상의 울릉분지에서의 생태학적 암시

Abstract

Patterns of recent sea level rise in the East/Japan Sea (EJS) are investigated through the analyses of TOPEX/ Poseidon (T/P) sea level anomalies, thermosteric sea level (TSL) and tide gauge data. The 9-year long T/P analyses reveal average trends of 5.4 ± 0.3 mm yr–1 for all of EJS, which is much larger than the global rates of 3.1 ± 0.4 mm yr–1 found by Cabanes et al. [2001]. This T/P rate compares relatively well with those from TSL data and tidal sea level gauges, indicating that sea level rise in the EJS is mainly due to thermal expansion. The southern EJS shows a non-uniform sea level trend pattern, with larger rates in the Ulleung and Yamato basins. This non-uniform pattern is discussed in terms of variable thermal expansions arising from a recent decadal trend in the temperature anomaly in the upper layer of the two basins. The 40-year-long TSL time series also reveals a decadal oscillation in the Ulleung and Yamato basins. It is hypothesized that the long-term oscillation in the southern EJS may be related to decadal variability of the heat content anomaly in the upper 300 m of the Pacific Ocean, as reported by Levitus et al. [2000], and to eddy fluctuations in the southern EJS. Whether or not the ecosystem in the EJS is responding to these changing physical signals is discussed by comparing surface chlorophyll-a and temperature structure in the Ulleung Basin.