AON: Monitoring the Western Arctic Boundary Current in a Warming Climate

随着地球气候在过去几十年里变暖，我们的星球经历了许多深刻的变化。没有任何地方的变化比北冰洋更显著，也发生得更快。冰盖正在融化，水正在变暖，风暴变得更加强烈和频繁，基本的环流模式正在改变。我们的项目关注的是通过白令海峡进入北冰洋的太平洋水的命运。太平洋水在北极西部生态系统中起着至关重要的作用。在冬季，冷水会提供营养物质，刺激食物链底部的浮游植物生长。在夏季，温暖的海水融化冰盖，为北冰洋提供淡水。在水穿过白令海峡以北的楚科奇海后，其中一些水在大陆架边缘形成一股狭窄的水流，向东流动。作为我们项目的一部分，我们将继续保持位于水流中心的系泊设备，以测量其物理和生物特性。自2002年以来，该系泊设备一直在部署(有一些空白)，在此期间，它测量了需要放在不断演变的北极系统背景下的显著变化。此外，我们将在服务系泊时对当前和邻近水域进行船上调查，以提供对太平洋水域命运的更大范围的看法。监测系泊地点位于152oW处，靠近波弗特海陆架断裂，位于铂下游约150公里处。巴罗。它将从2016年秋季到2018年秋季部署两年。这将把这个地点的时间序列延长到13年。系泊设备使用两个ADCP记录水柱和浮冰的速度，并使用沿钢丝分布的一系列MicroCats测量温度、盐度和压力。叶绿素荧光和硝酸盐将在35米处(在系泊设备的顶部漂浮处)进行测量，而位于系泊设备底部附近的被动声记录器将记录海洋哺乳动物的叫声。浮游动物密度将使用ADCP后向散射数据进行估计。在其他方面，这将使我们能够确定有多少水、热量、营养物质、叶绿素和淡水被海流输送，更重要的是，我们可以评估北冰洋内部和边界水域之间发生了多少交换。沿波弗特斜坡的上升流在所有季节都会发生，而且随着气候变暖，上升流似乎还会增加。系泊非常适合于量化上升流以及发生的任何下流。船上的抽样将包括对一些分布的生物观测站横断面的抽样，这将有助于正在进行的时间序列。

As Earth's climate has warmed over the past few decades, our planet has experienced a multitude of profound changes. Nowhere have the changes been more pronounced, nor happened as quickly, as in the Arctic Ocean. Pack-ice is melting, water is warming, storms are becoming stronger and more frequent, and basic circulation patterns are being altered. Our project focuses on the fate of the Pacific water that enters the Arctic Ocean through the Bering Strait. Pacific water plays a critical role in the western Arctic ecosystem. In wintertime the cold inflowing water provides nutrients that spur the growth of phytoplankton at the base of the food chain. In summertime, the warm water melts pack ice and provides freshwater to the Arctic Ocean. After the water crosses the Chukchi Sea, north of Bering Strait, some of it forms a narrow current at the edge of the shelf and flows eastward. As part of our project we will continue to maintain a mooring positioned in the center of the current to measure its physical and biological properties. The mooring has been deployed (with a few gaps) since 2002, and during this time it has measured striking changes that need to be placed in the context of the evolving Arctic system. In addition, we will carry out shipboard surveys of the current and adjacent waters when we service the mooring, to provide a larger-scale view of the fate of the Pacific water. The monitoring mooring is situated at 152oW near the Beaufort Sea shelf break, roughly 150 km downstream of Pt. Barrow. It will be deployed for two years from fall 2016 to fall 2018. This will extend the time series at this location to 13 years. The mooring records the velocity of the water column and pack ice using two ADCPs, and measures temperature, salinity, and pressure using a series of MicroCats spaced along the wire. Chlorophyll fluorescence and nitrate will be measured at 35 m (at the top float of the mooring), and a passive acoustic recorder situated near the base of the mooring will record marine mammal calls. Zooplankton concentration will be estimated using the ADCP backscatter data. Among other things, this will allow us to determine how much water, heat, nutrients, chlorophyll, and freshwater are transported by the current, and, importantly, assess how much exchange occurs between the interior of the Arctic Ocean and the boundary waters. Upwelling occurs during all seasons along the Beaufort slope, and it appears to be increasing as the climate warms. The mooring is ideally suited to quantify the upwelling, as well any downwelling that occurs. The shipboard sampling will include sampling of some of the Distributed Biological Observatory transects, which will contribute to those ongoing time series.