A Salt Finger Tracer Release Experiment

0081502施密特将在热带大西洋西部广泛的温盐阶梯区域进行广泛的野外试验，以研究双扩散在次表层水团转化中的作用。一种有目的的示踪剂(六氟化硫SF6)将被释放到楼梯中间附近的一层中，以获得对垂直混合和横向扩散的9个月的可靠测量。用剖面仪测量细微结构将确定湍流动能和热方差的耗散率。这些耗散率与垂直扩散系数的关系公式在很大程度上取决于混合的能量来源是盐指运动还是湍流。这项实验将确定这两个源对示踪剂、盐和热的垂直混合的相对贡献。系泊的CTD/Current剖面仪将用于将精细和微结构调查与长期示踪剂分散联系起来。希望这项工作将有助于改进大气环流和气候预报模式的昼夜混合参数。

0081502 SchmittAn extensive field experiment will be conducted in the area of the extensive thermohaline staircase in the western tropical Atlantic to investigate the role of double diffusion in subsurface water mass transformation. A purposeful tracer (Sulfur hexafluoride SF6) will be released into a layer near the middle of the staircase to obtain a robust 9-month measurement of vertical mixing and lateral dispersion. Surveys of fine- and microstructure with a profiling instrument will determine the dissipation rates of turbulent kinetic energy and thermal variance. Formulae for the relationship of these dissipation rates to vertical diffusivity depend dramatically on whether the source of energy for mixing is salt fingering or turbulence. This experiment will determine the relative contribution of these two sources to the vertical mixing of tracer, salt and heat. A moored CTD/Current profiler will be used to relate fine- and microstructure surveys to the long term tracer dispersion. The hope is that the work will lead to improved parameterizations of diapycnal mixing for general circulation and climate prediction models.