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

在过去的几十年里，随着地球气候的变暖，我们的星球经历了许多深刻的变化。没有哪个地方的变化比北冰洋更明显，发生得也更快。浮冰正在融化，海水正在变暖，风暴变得更强更频繁，基本的循环模式正在改变。我们的项目关注通过白令海峡进入北冰洋的太平洋水的命运。太平洋的水在北极西部生态系统中起着至关重要的作用。在冬季，流入的冷水提供了营养物质，刺激了食物链底部浮游植物的生长。夏季，温暖的海水融化了浮冰，为北冰洋提供了淡水。当水穿过白令海峡以北的楚科奇海后，其中一些在陆架边缘形成狭窄的水流向东流动。作为我们项目的一部分，我们将继续在洋流中心维持一个系泊点，以测量其物理和生物特性。自2002年以来，该系泊已经部署（有一些空白），在此期间，它已经测量了需要在不断发展的北极系统背景下放置的惊人变化。此外，我们在服务系泊时，亦会对现时及邻近水域进行船载调查，以更大规模地观察太平洋水域的命运。监测系泊位于152oW，靠近波弗特海大陆架断裂，位于巴罗岛下游约150公里处。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。系泊系统使用两个ADCPs记录水柱和浮冰的速度，并使用沿电缆间隔的一系列microcat测量温度、盐度和压力。叶绿素荧光和硝酸盐将在35米（系泊的顶部浮子）处测量，而位于系泊底部附近的被动声波记录仪将记录海洋哺乳动物的叫声。浮游动物浓度将使用ADCP反向散射数据进行估计。除其他事项外，这将使我们能够确定有多少水、热量、营养物质、叶绿素和淡水被洋流输送，重要的是，评估北冰洋内部和边界水域之间发生了多少交换。上升流在波弗特斜坡的所有季节都有发生，而且随着气候变暖，上升流似乎在增加。系泊非常适合量化上升流，以及任何发生的下升流。船上采样将包括一些分布式生物观测站样带的采样，这将有助于那些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.