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學生專區

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114/03/10 12:00 彭仁平博士(University of Western Australia, Australia)演講

演講公告
張貼人:網站管理員公告日期:2025-03-05
 
演 講 公 告
 

講題:Frontiers in Surface Mixed Layer Dynamics and Turbulence

 

主講人:彭仁平 博士

University of Western Australia, Australia


 
時間:03月10日(星期一)12:00
 

地點:中央大學科學一館S-325教室
 

摘要:
 
  The surface mixed layer (SML) has long been recognized as a key regulator of energy, momentum, and gas exchange between the atmosphere and the ocean, playing a fundamental role in large-scale upper-ocean dynamics. However, recent research has highlighted the importance of fine-scale dynamics, such as diurnal warm layers (DWLs) and surface-layer fronts, in modulating mixing, stratification, and vertical transport within the SML. While both processes have been studied individually, their interactions remain largely unexplored. This study investigates the coexistence and interplay of DWLs and surface-layer fronts using field observations and a turbulence closure model in an eddy-rich tropical ocean subjected to intense solar heating and weak winds. We found that the presence of a DWL isolates the deeper layers of the SML from diabatic and frictional surface forcing, causing these layers to quickly become non-turbulent while remaining in a state of marginal stability. This condition suggests that small perturbations from local processes, such as internal tides and waves, can easily trigger instability and turbulence. Additionally, frontal dynamics were observed to deepen the SML, allowing near-surface diurnal shear associated with DWL dynamics to penetrate to greater depths during nighttime, compared to conditions without a front, thereby facilitating the vertical transport of heat and tracers. Our findings underscore the necessity of accurately representing the interactions between DWLs and surface-layer fronts to enhance the precision of ocean circulation and climate models.
最後修改時間:2025-03-05 PM 2:57

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