Collaborative Research: Arctic Land Fast Sea Ice Formation in the Presence of Fresh Water Input

近年来，北极最显著的变化之一是海冰范围和时间的变化。 近岸海冰的性质和季节性周期的变化，对利用近岸海冰作为狩猎和运输平台的土著社区特别重要。 观测和模型预测还表明，由于冰川和冰盖的融化、永久冻土的融化和陆地上的降水增加，流入沿海海洋的淡水径流也会增加。 这些径流会影响秋季形成的海冰。 在淡水影响下形成的海冰揭示了盐度、孔隙度和渗透性的差异，从而揭示了其光学和机械特性。 该项目将提供在淡水影响条件下海冰形成和结构的独特观测。该项目将通过为研究生培训提供支持，为STEM劳动力发展做出贡献。 它也将吸引来自达特茅斯的本科生？妇女参与科学项目。 一名本科生将参加春季野外工作。 该项目还将申请对PolarTREC教师的支持。 将提供K-12年级的外展活动，并将利用华盛顿大学的现有项目，例如参加太平洋科学中心的极地科学周末。 向沿海海洋的淡水排放通过改变经历冻结的沃茨的盐度和温度来影响海冰中的热力学过程。 这个为期三年的试点项目旨在研究沿海海洋的海冰形成和结构，同时解决以下重要问题：1。与开放海洋中的海冰相比，在有大量淡水输入的地方形成和生长的海冰的微观结构和盐水袋网络有何不同？2.我们能否在远程收集数据的同时，在敏感的近岸地区就地监测冻结的开始、冻结速度和冰的类型？3.微结构如何影响沿沿着冰芯长度的热传递？该项目将联合收割机结合最近开发的观测和取样技术，并综合实地监测以及海冰物理和化学特性方面的专门知识。海冰的形成，增长速度和盐度将在现场监测的淡水输入的位置在生长季节的过程中使用钢丝梯。 氧同位素比率和光学薄片地层学将用于量化淡水影响。 将使用X射线微计算机断层摄影术来表征冰芯上每沿着1厘米间隔的孔隙度和盐水通道拓扑结构，并提供关于受淡水影响的冰的微结构差异的定量数据。 实验室测试和建模将被用来检查通过海冰核心在其原位温度梯度，作为微结构地层学的功能，通过热传递。

One of the most notable changes in the Arctic during recent years has been the variability in sea ice extent and timing. Changes in the character and seasonal cycle of nearshore sea ice is of particular importance to indigenous communities that use the nearshore sea ice as a platform for subsistence hunting and transportation. Observations and model projections also suggest increasing freshwater runoff to the coastal ocean from increased melting of glaciers and ice sheets, thawing of permafrost, and precipitation over land. This runoff impacts the sea ice that forms in the fall. Sea ice formed under freshwater influence reveals differences in salinity, porosity, and permeability, and thus its optical and mechanical properties. This project will provide unique observations of sea ice formation and structure under conditions of freshwater influence.This project will contribute to STEM workforce development through provision of support for the training of a graduate student. It will also entrain undergraduate students from Dartmouth?s Women in Science Project (WISP). One undergraduate will participate in the spring field work. The project will also apply for support for a PolarTREC teacher. K-12th grade outreach activities will be offered and will leverage existing programs at University of Washington such as participation in the Polar Science Weekend at the Pacific Science Center. The freshwater discharge to the coastal ocean affects thermodynamic processes in sea ice by changing salinity and temperature of the waters undergoing freezing. This three-year pilot project is designed to study sea ice formation and structure in the coastal ocean, while addressing the following important questions:1. How do microstructure and the brine pocket network differ in sea ice that forms and grows where there is significant fresh water input compared to sea ice in the open ocean?2. Can we monitor the onset of freezing, freezing rate and ice type in situ in sensitive nearshore areas, while collecting data remotely?3. How does microstructure affect heat transfer along the length of an ice core?The project will combine recently developed observation and sampling technologies, and integrate expertise in field monitoring, and physical and chemical sea ice characterization. Sea ice formation, growth rate, and salinity will be monitored in situ at a location of freshwater input during the course of a growth season using a wire ladder. Oxygen isotopic ratios and optical thin section stratigraphy will be used to quantify freshwater influence. X-ray micro-computed tomography will be used to characterize porosity and brine channel topology at 1 cm intervals along ice cores and provide quantitative data on microstructural differences in ice influenced by the freshwater. Laboratory tests and modeling will be used to examine heat transfer through sea ice cores held at their in situ temperature gradient, as a function of microstructural stratigraphy.