Weather-Driven Coastal Dynamics in a Tide-Dominated Area: Cases from Spring 2016 along the West Coast of Korea.

Kim, Baek-Jin; Lee, Dong Eun; Ro, Young-Jae; Jeong, Kwang-Young

Kim, B.-J.; Lee, D.E.; Ro, Y.-J., and Jeong, K.-Y., 2021. Weather-driven coastal dynamics in a tide-dominated area: Cases from Spring 2016 along the west coast of Korea. Journal of Coastal Research, 37(3), 494–505. Coconut Creek (Florida), ISSN 0749-0208. Analyses of current dynamics recorded using multilayer current meters in Spring 2016 (15 April–17 May, 32 d) at two stations near Kkotji Beach in Anmyeon-do, Yellow Sea, Korea, are presented. Harmonic analysis is applied to identify tidal characteristics in the study area. A slightly rotational current pattern is detected at ST01, while oscillations predominantly in north–south orientation are detected at ST02. Nontidal residual currents and the concurrent surface atmosphere data are analyzed together. Residual currents converge (diverge) between ST01 and ST02 following the increase (decrease) in thickness between two stations. Using advanced statistical methods, the spatial patterns of such dynamic events are shown with their association with surface atmosphere. Complex correlation analysis reveals that residual currents are significantly correlated with abrupt surface wind fluctuations associated with extratropical cyclones. The characteristics of residual currents and surface wind vectors are further analyzed, using complex empirical orthogonal functions (CEOF). The first residual current mode (R1) accounts for 46.8% of the total variation, while the second mode (R2) accounts for 24.9%. R1 represents a wind-induced component in the longshore direction, while R2 represents a bottom-driven component in the opposite direction. Both the modes correlate significantly with the first wind mode (W1, longshore wind), which leads the associated residual current modes by a few hours. Spectral analysis indicates that the two significant periods of surface wind and residual current modes are well matched to each other, exhibiting cycles of 1.6 and 4 days.

SOUTH Korea; CYCLONES; ORTHOGONAL functions; HARMONIC analysis (Mathematics); STATISTICAL correlation; TIDAL currents

Journal of Coastal Research, 2021, Vol 37, Issue 3, p494

0749-0208

Academic Journal

10.2112/JCOASTRES-D-20-00087.1