A Salt Finger Tracer Release Experiment - Analysis

盐指示踪剂释放实验 - 分析

• 批准号: 0350743
• 负责人: James Ledwell
• 金额: $ 70.27万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-15 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0350743&HistoricalAwards=false
• 关键词: Salt; Finger; Tracer; Release; Experiment

ABSTRACTOCE-0350743This research team successfully completed a two-year tracer and turbulence field study in the Tropical North Atlantic Ocean and Caribbean Sea, in an area prone to salt-finger instability. Preliminary results from the experiment are that the vertical diffusivity of the passive tracer in the area showing signs of salt-fingering was 4-5 times greater than elsewhere. Diffusivity for heat was about half that of the tracer, and that the energy dissipation was much smaller than would be expected for shear-driven mixing, both of which are expected for mixing due to salt fingers. This project is for the extended analysis of the data from the field study with the following objectives: to accurately determine the vertical mixing of tracer and heat within the staircase region and outside of it; to evaluate the roles of shear and salt finger instability in the formation and maintenance of staircases and the enhancement of mixing; to develop a parameterization of diffusivities of heat and salt in regions of the ocean susceptible to salt fingering for use in numerical models; to evaluate the role of enhanced mixing in the staircase region in regional transport of heat and salt and in water mass modification; to analyze the efficient zonal dispersion of the tracer patch, and lateral mixing and stirring of the tracer patch with the help of numerical models; and to publish the results of the research. The project will have broader impacts through the training of a graduate student, international collaborations and contribution to parameterizations for modeling.

这个研究小组在热带北大西洋和加勒比海一个容易发生盐指不稳定的地区成功地完成了一项为期两年的示踪剂和湍流场研究。实验的初步结果是，在显示盐指迹象的区域，被动示踪剂的垂直扩散率比其他地方大4-5倍。 热扩散率约为示踪剂的一半，并且能量耗散远小于剪切驱动混合的预期值，这两者都是由于盐指而预期的混合。 该项目是为了对实地研究的数据进行扩展分析，其目标如下：准确确定阶梯区域内外示踪剂和热量的垂直混合;评估剪切和盐指不稳定性在阶梯形成和维持以及混合增强中的作用;在易受盐指进影响的海洋区域制定热量和盐的扩散系数参数，用于数值模型;评估阶梯区域内强化混合在区域热盐迁移和水质改变方面的作用;借助数值模型分析示踪剂斑的有效带状扩散以及示踪剂斑的横向混合和搅拌;并发表研究结果。 该项目将通过培训一名研究生、开展国际合作和促进建模参数化产生更广泛的影响。