북서태평양의 13일주기 순압 해양 반응

Abstract

Ocean bottom pressure measurements from an array of 43 pressure-recording inverted echo sounders, which were part of the Kuroshio Extension System Study (KESS), reveal fluctuations of about 13-day period in the Northwestern Pacific. The fluctuation is characterized by “common mode” which shows coherent in-phase oscillations with a relatively large amplitude in the northeastern part of the observational domain. It also shows energetic fluctuations in the winter season during the 2-year observational period. Regression analysis with wind stress curl field reveals a significant correlation between them, which suggests that the near 13-day barotropic ocean response observed from the bottom pressure array is driven by the large-scale atmospheric forcing in the Northwestern Pacific. This finding is confirmed by a daily-wind forced barotropic ocean model that produces similar near 13-day sea level fluctuations. fluctuation is characterized by “common mode” which shows coherent in-phase oscillations with a relatively large amplitude in the northeastern part of the observational domain. It also shows energetic fluctuations in the winter season during the 2-year observational period. Regression analysis with wind stress curl field reveals a significant correlation between them, which suggests that the near 13-day barotropic ocean response observed from the bottom pressure array is driven by the large-scale atmospheric forcing in the Northwestern Pacific. This finding is confirmed by a daily-wind forced barotropic ocean model that produces similar near 13-day sea level fluctuations.