日本地球惑星科学連合2022年大会

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[E] ポスター発表

セッション記号 A (大気水圏科学) » A-OS 海洋科学・海洋環境

[A-OS16] Frontiers of Ocean Mixing Research

2022年6月1日(水) 09:00 〜 11:00 オンラインポスターZoom会場 (8) (Ch.08)

コンビーナ:日比谷 紀之(東京大学大学院理学系研究科地球惑星科学専攻)、コンビーナ:Lamb Kevin G(University of Waterloo)、伊地知 敬(The University of Tokyo)、座長:伊地知 敬(The University of Tokyo)

09:00 〜 11:00

[AOS16-P03] Enhanced internal tidal mixing in the Philippine Sea mesoscale environment

*Jia You1、Zhenhua Xu1、Qun Li2、Robin Robertson3、Peiwen Zhang1 (1.Institute of oceanology Chinese academy of sciences、2.Polar Research Institute of China、3.China-ASEAN College of Marine Science, Xiamen University Malaysia)

キーワード:Internal tide, turbulent mixing, wave-driven mixing

Turbulent mixing in the ocean interior is mainly attributed to internal wave breaking; however, the mixing properties and the modulation effects of mesoscale environmental factors are not well known. Here, the spatially inhomogeneous and seasonally variable diapycnal diffusivities in the upper Philippine Sea were estimated from Argo float data using a strain-based, fine-scale parameterization. Based on a coordinated analysis of multi-source data, we found that the driving processes for diapycnal diffusivities mainly included the near-inertial waves and internal tides. Mesoscale features were important in intensifying the mixing and modulating of its spatial pattern. An interesting finding was that, besides near-inertial waves, internal tides also contributed significant diapycnal mixing in the upper Philippine Sea. The seasonal cycles of diapycnal diffusivities and their contributors differed zonally. In the midlatitudes, wind mixing dominated and was strongest in winter and weakest in summer. In contrast, tidal mixing was more predominant in the lower latitudes and had no apparent seasonal variability. Furthermore, we provide evidence that the mesoscale environment in the Philippine Sea played a significant role in regulating the intensity and shaping the spatial inhomogeneity of the internal tidal mixing. The magnitudes of internal tidal mixing were greatly elevated in regions of energetic mesoscale processes. Anticyclonic mesoscale features were found to enhance diapycnal mixing more significantly than cyclonic ones