Seasonal Ice Cover and its Impact on the Epipelagic Community in the Northwestern Weddell Sea: Long Time-Series Monitoring

9315029史密斯：南大洋浮冰的年度膨胀和消退是世界海洋中最大的季节性过程。冰盖的这种季节性迁移对海洋水柱上100米处的远洋群落产生了深远的影响，在那里，冰盖与海鸟和哺乳动物等顶端捕食者之间的相互作用最为强烈。这一独特的远洋群落主要是通过船舶作业进行研究的。然而，在对浮冰下的上层群落进行船上采样方面存在着公认的问题，需要在足够长的时间尺度上监测这一群落，以检查这一环境的极端时间变异性。为了检查连续的时间变异性，该项目将开发一种垂直剖面泵采样器，用于在威德尔海浮冰下可编程的深度间隔内采集浮游动物和微型浮游动物。一旦开发和现场测试，该仪器将与先前开发的向上俯视、垂直剖面声阵列同时部署，为期一年。联合系泊项目将监测每年7-8个月冰盖地区水柱上部100米处可声探测到的浮游动物和微型浮游动物的垂直分布、丰度和大小频率。该项目还将包括在为期一年的实地研究过程中对三个航次进行的季节性船上采样。这些长期系泊装置的成功部署和实地数据的检索将有助于更好地了解南大洋上层群落如何在厚厚的冰层下发挥作用。这是极地方案办公室和海洋科学部共同发起的项目。***

9315029 Smith The annual expansion and retreat of pack ice in the Southern Ocean are the largest seasonal processes in the World Ocean. This seasonal migration of the ice cover has a profound impact on the pelagic community in the upper 100 m of the oceanic water column where the interactions between ice cover and apex predators, such as seabirds and mammals, are most intense. This unique pelagic community has been mainly studied with ship-based operations. However, there are well recognized problems associated with shipboard sampling of the epipelagic community under pack ice and the need to monitor this community on long-time scales sufficient to examine the extreme temporal variability of this environment. To examine continuous temporal variability, the project will develop a vertically-profiling pump sampler for the collections of zooplankton and micronekton over programmable depth intervals under pack ice in the Weddell Sea. Once developed and field tested, this instrument will be deployed concurrently with previously developed upward-looking, vertically-profiling acoustic arrays for a period of one year. The combined mooring project will monitor the vertical distribution, abundance and size frequency of acoustically detectable zooplankton and micronekton in the upper 100 m of the water column in an area that experiences ice cover during 7-8 months of the year. This project will also include seasonal shipboard sampling on three cruises over the course of the one year field study. A successful deployment of these long-term mooring arrays and retrieval of data from the field will contribute to a greater understanding of how epipelagic communities function under pack ice in the Southern Ocean. This is a jointly sponsored project of the Office of Polar Programs and the Division of Ocean Sciences. ***