Collaborative Research: The Norrona Project: An International Collaboration for Sustained Studies of the Meridional Overturning Circulation between Denmark, the Faroes and Iceland

横跨北大西洋北部的温暖咸水的存在和流动对形成中欧和北欧的温和气候起着关键作用。这种流动在很大程度上是由北欧海的大量热量损失控制的，这些热量损失将这些水转化为非常稠密的水，最终溢出到北大西洋深处。自2008年以来，北大西洋流入北欧海的水流已经被测量过了它经过的天然阻塞点：法罗-设得兰海峡（FSC）和冰岛-法罗海脊（IFR）。测量结果来自船上的声学多普勒电流剖面仪（ADCP），该仪器沿公海渡轮M/F Norröna的轨道以高水平分辨率扫描电流。虽然这已经取得了巨大的成功，但在冬季恶劣的天气中，气泡被扫下来并干扰仪器。为了缓解这个问题，该仪器最近被移到了更靠后的skeg位置，那里的气泡预计会更少。该项目将使研究人员能够评估数据质量的改进，并在未来两年参与仪器的操作和科学分析，在此期间，该操作将移交给挪威卑尔根海洋研究所（IMR）和法罗海洋研究所的科学家。冰岛-法罗-苏格兰海岭分隔了两个巨大而截然不同的水团系统（北大西洋和北极地中海），它们通过温暖、含盐的流入和稠密的水通过海岭的深隙流出进行交流。通过这些ADCP电流曲线，再加上同一艘船上自动部署在选定地点的xbt的温度曲线，可以量化流入量。在较短的时间尺度上，交换可能是由风驱动的，而在较长的时间尺度上（季节性和较长的）浮力损失必须是最重要的。通过持续和改进Norröna对流入和通过深隙监测流出的系泊adcp（法罗-挪威计划）的监测，人们可以相当详细地检查这些通量对时变大气强迫的时空响应，包括众所周知的北大西洋涛动。

The presence of and flow of warm salty water across the northern North Atlantic plays a key role in shaping the mild climate of central and northern Europe. This flow is in large measure controlled by enormous heat losses in the Nordic Seas that transform this water into very dense water that eventually spill back out into the deep North Atlantic. Since 2008, the flow of North Atlantic Water into the Nordic Seas has been measured where it passes through natural choke points: the Faroe-Shetland Channel (FSC) and the Iceland-Faroe Ridge (IFR). The measurements come from a shipboard acoustic Doppler current profiler (ADCP) that scans currents at high horizontal resolution along the track of the high-seas ferry M/F Norröna. While this has been a tremendous success, during rough weather in the winter bubbles are swept down and interfere with the instrument. To mitigate this problem, the instrument was recently moved further aft to the skeg, where fewer bubbles are expected. This project will allow the researchers to assess the improvement in data quality, and participate in the operation of the instrument and scientific analyses for another two years over which the operation will be handed over to scientists at the Institute of Marine Research (IMR) in Bergen, Norway and at Faroes Marine Research Institute. The Iceland-Faroe-Scotland ridge separates two large and distinctly different water mass systems (the North Atlantic and the Arctic Mediterranean) that communicate through warm, salty inflow and dense water outflow through the deep gaps in the ridge. The inflow is quantified with these ADCP current profiles, coupled with temperature profiles from XBTs deployed automatically at selected sites from the Automated eXpendable Instrument System (AXIS) on the same vessel. On shorter time scales exchange is likely wind-driven, while on longer time scales (seasonal and longer) buoyancy loss must be of paramount importance. With sustained and improved Norröna monitoring of the inflows and moored ADCPs monitoring the outflow through the deep gaps (a Faroes-Norway program), one can examine in considerable detail the space-time response of these fluxes to time-varying atmospheric forcing including the well-known North-Atlantic Oscillation.