Ice-tethered profiling from the land-fast ice on the Arctic shelves

所要求的设备是一对ITP（冰系剖面仪）CTD（电导率-温度-深度）和浊度/叶绿素荧光/CDOM（彩色溶解有机物）冰下剖面仪。ITP能够在海底和水冰界面之间频繁（每小时）进行垂直CTD和光学剖面测量，垂直分辨率约为2-5厘米。这种剖面数据对于评估冰盖下垂直湍流交换的强度是必不可少的。国际试验计划预计将用于三个NSERC-DG研究项目，题为“北极大陆架陆地固定冰下的垂直混合：效率和驱动机制”、“变化中的北极环境中辐射强迫对海冰融化-增长周期的作用”和“冰雪覆盖海冰的动力学和热力学过程”。所要求的设备将取代现有的不可靠和不适当的设备，以便对陆固冰下的水温、盐度和光学特性进行频繁和长期的自动剖面分析。现有的租借设备设计用于公海应用，不适合在陆地坚冰上作业。相比之下，ITP只是专门为部署、频繁和持久的自主CTD和冰下浊度/叶绿素/CDOM剖面而设计的设备。两个ITP剖面仪相距约15-20 km，与声学多普勒海流剖面仪（ADCP）一起部署在陆地固定冰上，从10月/11月到5月/6月，为期约7个月。实地观测在哈德逊湾的大鲸河口、加拿大群岛的雷索卢特海峡和剑桥湾以及格陵兰岛进行。每年，ITP和ADCP在不同地点之间重新分配。该项目将澄清不同环境条件下不同北极大陆架上垂直混合的作用。这将显着提高我们的理解区域变化的垂直混合和机制负责不稳定的北极大陆架下的陆地坚冰与北极建模的潜在影响。这对加拿大北极大陆架特别重要，预计将在那里广泛勘探石油和天然气。

The requested equipment is a pair of ITP (Ice-Tethered Profiler) CTD (Conductivity-Temperature-Depth) and turbidity/chlorophyll fluorescence/CDOM (Colored Dissolved Organic Matter) under-ice profilers. The ITPs are capable of frequent (hourly) vertical CTD and optical profiling between the sea floor and water-ice interface with vertical resolution of ~2-5 cm. Such profiling data are indispensable for assessing the intensity of the vertical turbulent exchange beneath the ice cover. The ITPs are expected to be used for three NSERC-DG research projects, entitled "Vertical mixing below the land fast ice on the Arctic shelves: Efficiency and driving mechanisms", "Role of radiative forcing on the sea ice melt-growth cycle in a changing Arctic environment" and "Dynamic and thermodynamic processes of snow covered sea ice". The requested equipment will replace existing unreliable and inappropriate equipment to conduct frequent and long-lasting autonomous profiling of water temperature, salinity, and optical characteristics below the land-fast ice. The existing loaned equipment designed for open ocean applications is unsuitable for operations from land-fast ice. In contrast, the ITP is only the equipment specifically designed for deployment, frequent and long-lasting autonomous CTD and turbidity/chlorophyll/CDOM profiling below the ice. The two ITP profilers separated by ~15-20 km are deployed from the land-fast ice in combination with Acoustic Doppler Current Profilers (ADCP) for ~ 7-month from October/November to May/June. The field observations take place at the Great Whale River Estuary in Hudson Bay, Resolute Passage and Cambridge Bay in the Canadian Archipelago and in Greenland. Every year, ITPs and ADCPs are reallocated between different locations. This project will clarify the role of vertical mixing on the different Arctic shelves for different environmental conditions. This will significantly improve our understanding of regional changes in vertical mixing and mechanisms responsible for instability below land-fast ice on Arctic shelves with potential implications for Arctic modeling. This is of particular importance for the Canadian Arctic shelf where the extensive exploration of oil and gas is expected.