Observations of strong near-bottom current after the passage of Typhoon Pabuk in the South China Sea

The vertical structure of current field in the northern South China Sea affected by the passage of Typhoon Pabuk is investigated using the observational data. The strong near-bottom current which has a duration of less than 1 day is observed twice whereas such a current is almost missing at some intermediate layers. It is suggested by the power spectral density that the typhoon strengthens the near-inertial current which is the most significant in the upper layer and the weakest in the middle layer after the passage of Pabuk. The wave-number rotary spectrum is calculated to study the characteristics of the energy which the typhoon injects into the ocean, and it is suggested that the strong near-bottom current may be supported by the transport of energy by the near-inertial waves induced by typhoon, thus the pressure gradients might be established through the continental slope and induce the strong near-bottom current. (C) 2011 Elsevier B.V. All rights reserved.