Southern Ocean JGOFS: Mesoscale Physical and Biological Processes at the Polar Front

南大洋 JGOFS：极地锋面的中尺度物理和生物过程

• 批准号: 9530758
• 负责人: Timothy Cowles
• 金额: $ 62.9万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-15 至 2000-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9530758&HistoricalAwards=false
• 关键词: Southern; Ocean; JGOFS; Mesoscale; Physical

95-30758 COWLES This research project is part of the US Joint Global Ocean Flux study (JGOFS) Southern Ocean Program aimed at (1) a better understanding of the fluxes of carbon, both organic and inorganic, in the Southern Ocean, (2) identifying the physical, ecological and biogeochemical factors and processes which regulate the magnitude and variability of these fluxes, and (3) placing these fluxes into the context of the contemporary global carbon cycle. The Southern Ocean is recognized as an important , yet poorly resolved, region of the world ocean. It is thought that this region plays a critical role in global carbon dynamics, as well as strongly influencing the flux of heat and salt between the Atlantic, Pacific, and Indian Oceans. Attempts to improve our understanding of this region and its role in the global carbon budget depend on our ability to adequately assess those processes which control or constrain the rates of carbon fixation and air- sea exchange of CO2. Recent observations in the Southern Ocean suggest that mesoscale variability in physical, chemical and biological properties limits our ability to provide accurate large-scale estimates of important rate processes. Our understanding of carbon flux in the Southern Ocean thus depends upon resolution of connections between mesoscale and large-scale processes. The mesoscale dynamics of the Polar Front region of the Antarctic Circumpolar Current will be investigated using an instrumented towed vehicle (SeaSoar) to resolve the physical and biological fields over horizontal spatial scales of 1-150 km, with 2m vertical resolution within the upper 400m. High resolution surveys of physical and biological properties will be made during three cruises in the Polar Front (Oct `97, Dec-Jan `97/'98, Mar `98). Towed instrumentation will document the physical and biological structure associated with mixing and interleaving of mesoscale features. The high resolution surveys of physical properties will allow the determination of the relationship between lateral processes and local vertical mixing. Resolution of these mesoscale circulation features will be critical for the evaluation of the properties measured at discrete sampling stations, and will provide the regional context for evaluation of carbon flux at given locations. Objectives are: 1) determine the characteristics and spatial scales of the physical and biological fields in the Polar Frontal region of the Antarctic Circumpolar Current system; 2) evaluate the role of mesoscale circulation in mixing heat, salt, and biogeochemical properties into and out of the euphotic zone; 3) determine, using bio-optical indices, the spatial scales of photoadaptation of the autorophic assemblage in the Polar Front region; 4) incorporate mesoscale patterns of physical and biological property distribution into a high resolution regional ocean circulation model.

95-30758 COWLES 该研究项目是美国全球海洋通量联合研究 (JGOFS) 南大洋计划的一部分，旨在 (1) 更好地了解南大洋的有机碳和无机碳通量，(2) 确定调节这些通量的大小和变异性的物理、生态和生物地球化学因素和过程，以及 (3) 将这些通量置于当代背景下 全球碳循环。 南大洋被认为是世界海洋中一个重要但尚未得到解决的地区。 人们认为该地区在全球碳动态中发挥着关键作用，并强烈影响大西洋、太平洋和印度洋之间的热量和盐通量。 提高我们对该地区及其在全球碳预算中的作用的了解的尝试取决于我们是否有能力充分评估那些控制或限制碳固定速率和二氧化碳海气交换速率的过程。 最近在南大洋的观测表明，物理、化学和生物特性的中尺度变化限制了我们对重要速率过程提供准确的大规模估计的能力。 因此，我们对南大洋碳通量的理解取决于中尺度和大规模过程之间联系的解决。 将使用仪器化牵引车（SeaSoar）研究南极绕极流极锋区域的中尺度动力学，以解析 1-150 km 水平空间尺度上的物理和生物场，在上部 400 m 内具有 2 m 垂直分辨率。 物理和生物特性的高分辨率调查将在极地锋线的三次巡航期间进行（97年10月、97年12月至98年1月、98年3月）。拖曳仪器将记录与中尺度特征的混合和交错相关的物理和生物结构。 物理特性的高分辨率调查将允许确定横向过程和局部垂直混合之间的关系。 这些中尺度环流特征的解析对于评估离散采样站测量的特性至关重要，并将为评估特定地点的碳通量提供区域背景。 目标是：1）确定南极绕极流系统极锋区物理场和生物场的特征和空间尺度； 2）评估中尺度循环在混合热、盐和生物地球化学特性进出真光带方面的作用； 3）利用生物光学指数确定极锋区域自养组合光适应的空间尺度； 4）将物理和生物特性分布的中尺度模式纳入高分辨率区域海洋环流模型。