Simulation of the cold dome and upwelling northeast of Taiwan in summer

doi:10.3969/j.issn.1001-909X.2017.02.001

Abstract

Abstract: The Kuroshio on-shelf intrusion northeast of Taiwan manifests as the subsurface Kuroshio water upwelling and a "cold dome" structure in summer. Using ROMS (Regional Ocean Modeling System) model, the three-dimensional structure of the cold dome and the circulation along with upwelling induced by Kuroshio intrusion were analyzed, and the mechanisms of the formation of upwelling were also discussed. Model results show that the center of the cold dome is located near 25.5°N, 122.5°E in the layers upper of 50 m with maximum 5 ℃ cooling, and close to the north end of Taiwan Island in the layers lower of 50 m. The result of current structures show that Kuroshio surface intrusion is not obvious at the north end of Taiwan Island. A cyclonic circulation exists near the region where the shelf break turns eastward. Upwelling mainly occurs near the large slope of shelf break, with two obvious routes of the subsurface water upwelled onto the shelf. One of the routes is north of the Taiwan Island and between the isobaths of 100 m and 200 m, while the other one is near the region where the shelf break turns eastward. In the upper layer, the advection term is the main dynamical factor of the upwelling. While in the near-bottom layer, both the advection and bottom friction terms contribute to the upwelling.

Key words: Kuroshio intrusion, cold dome, upwelling

CLC Number:

P731.2

LIU Xiao-hui, LIAN Tao. Simulation of the cold dome and upwelling northeast of Taiwan in summer[J]. Journal of Marine Sciences, 2017, 35(2): 1-10.

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