Long-term observations on the Bering Sea shelf: biophysical mooring data from mooring site 5

This project is a continuation of a long-term partnership between National Oceanic and Atmospheric Administration (NOAA) and North Pacific Research Board (NPRB). Moorings have been maintained on the southeastern Bering Sea shelf at four sites: M2 (56.9 N, 164.1 W) since 1995, M4 (57.9 N, 168.9 W) since 1996, M5 (59.9 N, 171.7 W) and M8 (62.2 N 174.7 W) since 2004. This project together with research by the NOAA program North Pacific Climate Research and Ecosystem Productivity (NPCREP) continued these measurements for the next three years (2008-2010). These moorings, together with observations along the 70 m isobath, are core to the long-term observations on the Bering Sea shelf. All four moorings are deployed on the 70m isobath. Key findings including the Oscillating Control Hypothesis (OCH), timing of spring bloom, the magnitude of increased temperature (>2 deg. C) and stability in the nutrient supply have all been a result of the data collected on these moorings. Data from M2 has quantified the warming that occurred over the southern shelf during 2001-2005. This project (O1.1) will continue the time series of temperature, salinity, fluorescence, currents, zooplankton abundance (Tracor Acoustic Profiling System (TAPS-8) at M2 and possibly M4), nitrate, and oxygen (at M2 and possibly M5) at four mooring sites on the Bering Sea shelf. In addition during the late spring and summer a surface mooring (two if ice permits) will be deployed that will measure meteorological variables (air temperature, humidity, barometric pressure, wind velocity and solar photosynthetically active radiation (PAR)). The surface moorings permit real time reporting of selected data. Data from these moorings are also critical to model verification. Products include mixed layer depth, heat content, temperature, position of the transition between southern pelagic-dominated shelf and northern benthic-dominated shelf, advection, nutrient supply and timing of the spring phytoplankton bloom.

本项目是美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）与北太平洋研究委员会（North Pacific Research Board, NPRB）长期合作的延续。团队在白令海东南部陆架的4个站点布设了长期锚系观测站：M2（56.9°N，164.1°W）自1995年起正式运行，M4（57.9°N，168.9°W）自1996年起正式运行，M5（59.9°N，171.7°W）与M8（62.2°N，174.7°W）自2004年起正式运行。本项目与NOAA下属的北太平洋气候研究与生态系统生产力（North Pacific Climate Research and Ecosystem Productivity, NPCREP）项目协同开展研究，将上述观测序列延续至2008-2010年的三年周期。这些锚系观测站连同沿70米等深线获取的观测数据，共同构成了白令海陆架长期观测的核心数据集，且4个锚系站点均布设于70米等深线处。基于这些锚系观测采集的原始数据，已衍生出多项核心研究成果，包括振荡控制假说（Oscillating Control Hypothesis, OCH）、春季浮游植物水华发生时间、升温幅度（超过2℃）以及营养盐供给稳定性等相关结论。其中，M2站点的观测数据量化了2001-2005年间白令海南部陆架的变暖过程。本项目（编号O1.1）将继续维持白令海陆架4个锚系站点的时间序列观测，观测要素包括温度、盐度、荧光值、海流、浮游动物丰度（M2站点将采用Tracor声学剖面系统（Tracor Acoustic Profiling System, TAPS-8）开展观测，M4站点视条件开展），以及硝酸盐与溶解氧（M2站点开展观测，M5站点视条件开展）。此外，在晚春与夏季时段，团队将布设水面锚系观测系统（若海冰条件允许则布设2套），用于观测气象变量：气温、湿度、气压、风速以及光合有效辐射（Photosynthetically Active Radiation, PAR）。该水面锚系系统可实现选定观测数据的实时上报。上述锚系观测采集的数据同样对海洋模型验证工作具有关键支撑价值。本项目的衍生产品包括混合层深度、热含量、温度场分布、南部浮游生物占优陆架与北部底栖生物占优陆架之间的过渡带位置、平流输送过程、营养盐供给以及春季浮游植物水华的发生时间等。