High Resolution Underway Observations in Drake Passage: Ocean Physics

南极绕极流（ACC）是世界上最强的洋流，其流速比地球上所有河流的总和还要大100倍。 该项目继续对大西洋中心的海洋特性和变化进行长期研究，方法是使用美国南极计划的RV/AS LMGould补给船，对从蓬塔阿雷纳斯到帕尔默站的德雷克海峡进行重复断面调查。 该项目将提供有关南大洋锋面、表层水质量特性、热量和盐度收支的长期趋势和变化的信息。 本研究将有助于了解ACC对大气强迫在气候相关时间尺度上的响应，以及它在驱动南大洋纬向翻转环流中的作用。该项目将继续在德雷克海峡进行高分辨率、近乎重复的XBT/XCTD/ADCP断面采样，以研究海洋温度、盐度、海流和南极绕极流后向散射的变化模式。 这些数据将捕捉从季节到年际的时间尺度上的变异性，以及从当前核心到涡旋的空间尺度上的变异性。利用现有近20年的数据，主要科学目标是分析德雷克海峡时间序列，并（1）描述季节性和长期海洋能量分布与风、浮力和地形强迫和下沉之间的关系，（2）描述ACC锋面、水团和上升流的季节性和长期变化与海洋地球化学变化之间的关系。继续收集数据、进行质量控制并向更广泛的海洋学界传播德雷克海峡数据集是该项目的关键组成部分。

The Antarctic Circumpolar Current (ACC) is the strongest ocean current in the world, with a flow rate more than 100 times greater than all the rivers on Earth combined. This project continues a long-term study of ocean properties and variability in the ACC by repeat transects across the Drake Passage from Punta Arenas to Palmer Station using the USAP supply ship RV/AS LMGould. This project will provide information about long term trends and variability in Southern Ocean fronts, surface water mass properties, heat, and salinity budgets. This study will contribute to understanding the response of the ACC to atmospheric forcing on climate relevant time scales, and its role in driving the meridional overturning circulation of the Southern Ocean. These data represent the only year-round shipboard measurements in the Southern Ocean.This project will continue high-resolution, near-repeat XBT/XCTD/ADCP transect sampling in Drake Passage in order to study modes of variability in ocean temperature, salinity, currents and backscatter in the Antarctic Circumpolar Current (ACC). The data will capture variability on time scales from seasonal to interannual and on spatial scales from current cores to eddies. With almost two decades of data now available, the primary science objectives are to analyze the Drake Passage time series and (1) describe and relate the seasonal and long-term ocean energy distribution to wind, buoyancy and topographic forcing and sinks, and (2) describe and relate seasonal and long-term changes in the ACC fronts, water masses and upwelling to biogeochemical variability. The continued data collection, quality control and dissemination of the Drake Passage data sets to the broader oceanographic community are critical components of the project.