Principal Component Analysis on Horizontal Acoustic Doppler Current Profilers measurement

Principal Component Analysis (PCA) is proposed on long-beam velocities of Horizontal Acoustic Doppler Current Profiler (HADCP) to reveal flow dynamics in near-bank regions and check simulation results, particularly Regional Ocean Modeling System (ROMS) performed for the Hudson River estuary (New York, USA). We here analyzed data measured by Horizontal Acoustic Doppler Current Profiler (HADCP) at West Point, on the inner bank, downstream of a bend. Results show an agreement between HADCP and ROMS in the first mode. Low-order PCA temporal coefficients have fluctuation in ebb tide which may be associated with topographically-generated eddies. In addition, it appears an asymmetry between ebb and flood in the second temporal coefficient. Tidal effect is found in lower order temporal coefficients and their spectra.