Laboratory Measurements of Heat and Salt Fluxes in Double-Diffusive Interleaving

摘要：本文将在实验室进行两类双扩散入侵实验。第一种是在典型的物性不连续排列中，当关闭将盐层水与糖层水分离的水闸时，会产生侵入性交错。（在实验室实验中，盐被用来代表海洋中的寒冷，缓慢扩散的糖被用来代表海洋中的盐。）第二种是一种新的排列，在这种排列中，连续的盐度水平梯度被相反的连续的糖水平梯度密度补偿，并且交错的侵入体同时在各处生长。这些实验将进行双重稳定，盐指法和扩散分层。对于这两类流动，将使用现代定量测量技术，如用于水平和垂直分量的粒子图像测速法，用于糖浓度和密度场的颜色偏振法和合成纹影法来确定温度(T)和盐(S)的水平和垂直通量，因为它们随施加的梯度而变化。本研究的预期结果是：(1)确定T和S的通量与施加的梯度有关的通量规律；(2)确定水平通量与垂直通量的关系；(3)诊断失稳机制和检验线性稳定性理论。预计将发现通量定律，这些定律可以按比例扩大，以确定海洋锋中水平混合的强度。由于改变后的海水参与了全球温盐环流，混合程度改变了热量向极地的输送，而热量向极地输送是全球变暖后果的一个关键组成部分。教学和培训将通过研究成果的整合和实验室设施在多个教学层面的使用来促进，包括研究生和本科生荣誉科学研讨会学生的项目以及与热那亚大学环境工程系的国际合作伙伴关系。

ABSTRACTOCE-0242535Two classes of experiments on doubly diffusive intrusions will be conducted in the laboratory. The first is the intrusive interleaving produced in the classical arrangement of property discontinuity when a sluice-gate is withdrawn which had separated salt-stratified water from sugar-stratified water. (Salt in the laboratory experiment is used as a proxy for cold in the ocean, slow-diffusing sugar as a proxy for ocean salt.). The second is a new arrangement in which a continuous horizontal gradient of salinity is density-compensated by an opposing continuous horizontal gradient of sugar, and interleaving intrusions grow everywhere simultaneously. These experiments will be performed for doudbly-stable, for salt-fingering, and for diffusive stratification. For both classes of flows modern quantitative measurements techniques such as particle-Image Velocimetry for horizontal and vertical components, color polarimetry and synthetic Schlieren for sugar concentration and density field will be used to determine the horizontal and vertical fluxes of temperature (T) and salt (S), as they vary with imposed gradients. The anticipated results of this study are (1) a determination of flux laws relating fluxes of T and S to imposed gradients; (2) a determination of relationship of horizontal to vertical fluxes and (3) a diagnosis of instability mechanisms and test of linear stability theories.The discovery of flux laws which can be scaled up to determine the magnitude of horizontal mixing in oceanic fronts is anticipated. Since the resulting modified waters participate in the global thermohaline circulation, the degree of mixing modifies the poleward transport of heat which is a crucial component of the consequences of global warming. Teaching and training will be promoted through the integration of research results and use of the laboratory facilities in many layers of teaching, including graduate students and undergraduate Honors Science Seminar students projects and an international partnership with the Dept. of Environmental Engineering, University of Genoa.