Storm-induced circulation in the Pearl River Estuary of China during super Typhoon Koryn

Abstract

This study presents a numerical investigation of storm-induced circulation and hydrographic distributions over the Pearl River Estuary (PRE) in South China's Guangdong Province during super Typhoon Koryn in June 1993. The nested-grid modelling system used in this study has three downscaling subcomponents: an outer-most sub-model with a coarse horizontal resolution of ~7 km for simulating surface elevations and depth-mean currents forced by wind and tides over China Seas from Bohai Sea to the northern South China Sea; and an inner-most sub-model with a fine resolution of ~1.2 km for simulating the three-dimensional estuarine circulation and hydrographic distributions in the PRE and adjacent waters. A parametric vortex is inserted into the coarse-resolution (0.5°) numerical weather forecast products to better represent the atmospheric pressure and wind stress associated with Koryn. Model results demonstrate that large surface elevations and intense surface currents are generated over the area of influence of the storm. Lagrange velocities of near-surface particles are also used to examine the effect of the storm on the movements and dispersion of near-surface particles over the study region. © IWA Publishing 2012.