Title :
Analysis of Decomposed Surface Currents in a Limited Area
Author :
Hisaki, Yukiharu
Author_Institution :
Dept. of Phys. & Earth Sci., Ryukyus Univ., Okinawa
Abstract :
A method of the Helmholtz decomposition for mapped surface currents on grid points is developed. This method is simple, and decomposed currents are not dependent on the distance from the open boundary. This decomposition is applied to surface currents observed by high-frequency (HF) radars. The observation was conducted from April to May 1998 east of Okinawa Island, Japan. The spectral analysis of decomposed currents reveals that the M2 tidal peak for rotational components is much smaller than that for divergent components, which suggests that the barotropic tidal components are mainly included in divergent currents. The real-vector empirical orthogonal function (EOF) analysis of decomposed currents reveals an embedded eddy, which is related with the convergence of currents
Keywords :
Helmholtz equations; ocean waves; oceanographic techniques; remote sensing by radar; HF radars; Helmholtz decomposition; M2 tidal peak; barotropic tidal components; empirical orthogonal function analysis; high-frequency radars; rotational components; spectral analysis; surface current analysis; Boundary conditions; Fluctuations; Frequency; Hafnium; Oceans; Poisson equations; Radar; Sea surface; Spatial resolution; Spectral analysis; Helmholtz decomposition; high-frequency (HF) radar; surface currents;
Journal_Title :
Oceanic Engineering, IEEE Journal of
DOI :
10.1109/JOE.2006.886082
