Submesoscale Ocean Fronts and Turbulence (SOFT) observatory

次尺度海洋锋和湍流 (SOFT) 天文台

• 批准号: 418247-2012
• 负责人: Chavanne, Cédric
• 金额: $ 2.04万
• 依托单位: Université du Québec à Rimouski
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=634203
• 关键词: Submesoscale; Ocean; Fronts; Turbulence; SOFT

Ocean fronts separate waters of different temperatures and salinities over distances ranging from a few tens of kilometers down to hundreds of meters, a range called submesoscale. The ocean surface is populated with a convoluted web of submesoscale fronts, featuring rapid subsurface vertical velocities of 10 to 100 meters per day, an order of magnitude stronger than in the rest of the ocean. They may therefore play an important part in the exchange of heat and gases between the atmosphere and the ocean interior, and in the supply of nutrients to the sun-lit zone where photosynthesis takes place. However, computing performances will not be sufficient for the foreseeable future to resolve submesoscales in global ocean models. We must therefore develop parameterizations that realistically reproduce the collective effect of submesoscale processes on the resolved larger scales. Submesoscale-resolving numerical simulations are now being run in idealized or regional settings, but observations of submesoscale processes have remained sparse. The most detailed observations have been obtained from short-term ship-borne campaigns, due to the necessity of sampling the vertical and horizontal structure of the upper ocean at high resolution over extended areas. There is a lack of long-term continuous observations to provide a statistical view of submesoscale dynamics in a wide range of environmental conditions. One of the goals of this proposal is to start filling this observational void. As a first step, in the next five years, the Lower St-Lawrence Estuary will provide a natural laboratory to acquire long-term continuous observations of submesoscale processes, using high-frequency radars and moored vertical profilers. These observations are intended to guide the development of parameterizations of the cumulative effects of submesoscale on larger-scale processes, based on the simplest dynamics able to reproduce the main observed features.

海洋锋面将不同温度和盐度的水域分开，距离从几十公里到几百米不等，这个范围被称为亚中尺度。海洋表面布满了一个错综复杂的亚中尺度锋面网，其地下垂直速度快，每天10到100米，比海洋其他地方强一个数量级。因此，它们可能在大气和海洋内部的热量和气体交换中发挥重要作用，并在向发生光合作用的阳光照射区提供营养物质方面发挥重要作用。然而，在可预见的未来，计算性能还不足以解决全球海洋模式中的亚中尺度问题。因此，我们必须发展参数化，以便在已解决的更大尺度上实际再现亚中尺度过程的集体效应。亚中尺度分辨率的数值模拟目前正在理想化或区域环境中运行，但对亚中尺度过程的观测仍然很少。由于需要在大范围内以高分辨率采样上层海洋的垂直和水平结构，因此从短期的船载运动中获得了最详细的观测结果。在广泛的环境条件下，缺乏长期的连续观测来提供亚中尺度动力学的统计观点。这项提议的目标之一就是开始填补这一观测空白。作为第一步，在未来五年内，下圣劳伦斯河口将提供一个天然实验室，利用高频雷达和系泊垂直剖面仪获得长期连续的亚中尺度过程观测。这些观测旨在指导基于能够重现观测到的主要特征的最简单动力学的亚中尺度对大尺度过程累积效应的参数化发展。