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

AON：在气候变暖的情况下监测北极西部边界流

• 批准号: 1504333
• 负责人: Robert Pickart
• 金额: $ 97万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1504333&HistoricalAwards=false
• 关键词: AON; Monitoring; Western; Arctic; Boundary

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.

在过去的几十年中，地球气候变暖，我们的星球经历了许多深刻的变化。在北极海洋中，这些变化的变化都没有更明显，也不是如此迅速。包装冰正在融化，水变暖，风暴变得更强大，越来越频繁，并且基本的循环模式正在改变。我们的项目着重于通过白令海峡进入北极海的太平洋水的命运。太平洋水在西方北极生态系统中起着至关重要的作用。在冬季，冷流水提供的营养素刺激了食物链底部的浮游植物的生长。在夏季，温水融化了冰块，并为北极海提供了淡水。水横穿白令海峡以北的丘奇海之后，其中一些在架子边缘形成狭窄的电流，并向东流动。作为我们项目的一部分，我们将继续保持在电流中心的系泊，以衡量其物理和生物学特性。自2002年以来，系泊设备已被部署（存在一些空白），在此期间，它测量了需要将其放置在不断发展的北极系统背景下的惊人变化。此外，我们将在服务系泊服务时对当前和相邻水域进行船舶调查，以提供对太平洋水的命运的更大范围。 监测系泊设备位于Beaufort Sea Break Break附近的152OW，在PT下游约150公里。巴罗。它将从2016年秋季到2018年秋季部署两年。这将在此地点将时间序列延长至13年。系泊记录了使用两个ADCP的水柱和冰的速度，并使用一系列沿着电线间隔的微胶囊来测量温度，盐度和压力。叶绿素荧光和硝酸盐将在35 m处测量（处于系泊的顶部浮子），并且位于系泊底部附近的被动声音记录器将记录海洋哺乳动物的呼叫。浮游动物浓度将使用ADCP反向散射数据估算。除其他事项外，这将使我们能够确定水，热，养分，叶绿素和淡水是由电流运输的，并且重要的是，北极海洋内部和边界水域之间发生了多少交换。上升的沿Beaufort斜坡的所有季节都发生，随着气候温暖，它似乎正在增加。系泊设备非常适合量化上升流以及发生的任何下降。船上的采样将包括对一些分布式生物观测口的采样，这将有助于那些持续的时间序列。