FORCING EVALUATION FOR OFFSHORE PLATFORMS IN THE SOUTH CHINA SEA USING A HYCOM-ROMS DOWNSCALING OCEAN MODEL

Abstract

 Oceanic forcing on offshore oil platforms deployed ubiquitously in the South China Sea (SCS) was evaluated from the medium-term reanalyses based on the in-house regional HYCOM-ROMS oceanic model and the JMA’s GPV-GSM global atmospheric analysis. An extreme value statistical analysis was conducted for determining the maximum surface currents and winds that may occur with multi-decadal exceedance probability. Wind stresses were most energetic off the eastern shore of the Malay Peninsula due to southwestward winter monsoons, while surface currents were intensified off the northern shore of Borneo Island. We assessed the mechanism behind the latter using a volume flux analysis at several cross-sections around the SCS. It was demonstrated that the remote forcing associated with the Kuroshio and Mindanao Currents triggered changes in the fluxes at the Luzon and Celebes Straits that are indirectly but pronouncedly influential to the coastal currents near the Borneo Strait.