Three Dimensional Dynamics of Freshwater Lenses in the Oceans Near Surface Layer
Three Dimensional Dynamics of Freshwater Lenses in the Oceans Near Surface Layer
复制标题
近表层海洋淡水透镜体的三维动力学
DOI：
10.5670/oceanog.2015.14
复制
发表时间：
2015
期刊：
影响因子：
2.8
通讯作者：
A. Fujimura
中科院分区：
文献类型：
--
作者：
A. Soloviev;S. Matt;A. Fujimura
摘要：热带辐合带的对流降雨在海洋表面产生淡水透镜。由于淡水和更咸的海水之间的密度差异很大，形成了强烈的压力梯度，导致淡水透镜以重力流的形式横向扩散。重力流本质上涉及三维动力学。作为一种有组织的结构，重力流也可能与周围的海洋和大气环境相互作用，并受到其影响。其中重要的环境因素包括背景层结和风应力。在某些条件下，传播的淡水透镜与盐跃层(障碍层)中的内波之间可能会产生共振相互作用，而与风应力的相互作用可能会在淡水透镜及相关混合中产生不对称。这两种类型的相互作用可以解释在热带海洋全球大气耦合海洋大气响应实验(TOGA COARE)期间观察到的与淡水透镜有关的一系列尖锐的锋面界面。我们使用计算流体力学工具进行了一系列数值模拟。这些数值试验旨在阐明不同环境条件下垂直和水平盐分通量之间的关系，以及这些盐分通量对障碍层和宝瓶座以及土壤水分和海洋盐度(SMOS)卫星图像形成的潜在影响。
Abstract : Convective rains in the Intertropical Convergence Zone produce lenses of freshened water on the ocean surface. Due to significant density differences between the freshened and saltier seawater, strong pressure gradients develop, resulting in lateral spreading of freshwater lenses in the form of gravity currents. Gravity currents inherently involve three-dimensional dynamics. As a type of organized structure, gravity currents may also interact with, and be shaped by, the ambient oceanic and atmospheric environment. Among the important environmental factors are background stratification and wind stress. Under certain conditions, a resonant interaction between a propagating freshwater lens and internal waves in the underlying halocline (the barrier layer) may develop, while interaction with the wind stress may produce an asymmetry in the freshwater lens and associated mixing. These two types of interactions working in concert may explain the series of sharp frontal interfaces observed in association with freshwater lenses during the Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment (TOGA COARE). We conducted a series of numerical simulations using computational fluid dynamics tools. These numerical experiments were designed to elucidate the relationship between vertical and horizontal fluxes of salinity under various environmental conditions and the potential impact of these fluxes on the barrier layer and Aquarius and Soil Moisture and Ocean Salinity (SMOS) satellite image formations.